Lister Engine Forum

Lister Engines => Petteroids => Topic started by: Rob PetterPJ2 on October 18, 2018, 12:01:52 AM

Title: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 18, 2018, 12:01:52 AM
Hi, I'm Rob from Amsterdam, NL, new to any forum.
English is not my native language, and with the technical stuff I have to look up the english words and I may not understand everything you may try to tell me, right away, but let's give it a try.

I had no experience working on a diesel engine before 4 years ago, but I do have a technical insight. I learn while doing, and I ask a lot and read a lot, especially now that there have been and are serious problems with this old machine. I'm used to open every household thing that's broken and try fix it, and mostly I can. But I know I'm still very much a beginner with diesel engines, compared to the advanced hobbyist mechanics.

I wish I had a manual for exactly this engine Petter PJ2, 22 HP air cooled. Motor nr 13724, put in a Harding life boat in 1972.
When, after a few years the engine started to show problems (smoke, overheating) small pieces of one piston appeared to have broken off, I had an engine revision workshop find me 2 new pistons (they got them from the Lister-Petter company) and have the cylinders honed by them.
Now that I've put the engine back together, and both cylinders firing, after little time (2 minutes various speeds, 10 minutes slow speed) the engine slows down, and when I turn it off, the flywheel can't be turned for a short while, and after that only with force. When the engine cooled down, it all turns easier, as normally. I guess it's a result of the pistons expanding by the heat and then get stuck in the cylinders. The oil in the carter is Shell Rimula R4 Multigrade 10W30.
A manual of a similar engine says, with new pistons one must indeed let the engine run first for just 2 minutes, without any load, then 10 minutes let it do some work, and then longer and longer before really having it run for a normal, longer trip. What worries me, is that the first two times the engine stopped after 2 minutes, for blocking itself. The third time after about 10 minutes running slow. The pistons, or at least one, gets stuck and the flywheel can't be turned for a minute or two.
How normal or abnormal is this? To me it doesn't 'feel' good, that the pistons get stuck.
Both cylinders seem to warm up normal, and develop an equal temperature.

1. Should I be worried about the piston clearance being too little?
2. What else could cause this rapid blocking, that seems so related to the heating up?
3. Who could provide a manual for exactly this engine?

I'll of course be happy to hear some responses
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 18, 2018, 01:18:20 AM

Your english is excelent so do not worry about that.  By " Blocking" I take it you mean  Siezing.  That is when the engine locks up and  won't turn because the parts tighten up on each other.

There is no way the engine should Sieze because the pistons heated up and swelled. The clearances are way too tight. The only way this could fix itself is to wear either the pistons or the bore or both so there is adequate clearance and neither is at all a good thing.  You will get the sides of the piston scrubbing and smearing and possibly breaking again as before. The place that did the job botched it.  Most times bores are  honed out then Finally finished to suit the pistons.  Maybe they missed the last step and only bored the block to the piston size not allowing for final finishing and clearances.

The engine needs to be torn down again and the clearances Checked and corrected. Make sure someone competent also check the barrels are round and Square to the block. I would also be checking oil pressure just in case it's not the pistons but the bearings. Unlikely but there is defiantly a substantial problem somewhere.

If the engine was overheating before rebuild, was this checked for blockages in the water jackets and passageways? If not you may be getting localized heating which is causing the Piston to Seize.
In any case, the engine needs to be pulled down again and these things Checked because engines should NOT sieze while running and the engine is doing a LOT of damage to itself by doing this.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 18, 2018, 10:14:40 AM
Hey Rob, I agree with every piece of advice from Glort, however he missed one thing(not like him), I would be looking at the piston ring gap. Piston rings grow as they get hot, if the gap between the two ends is too small the engine will seize after about five to ten minutes. Very easy to fix: remove the piston rings and place them in the cylinder, use the bare piston to push them down the cylinder so they are square to the bore. Use a set of feeler gauges to measure the piston ring gap at the top and bottom of the bore. If the gap is too small, file or grind the end of the ring until they are within specification. Do this for every piston ring and then reassemble. The problem should be solved.

Your English is very good, good luck, let us know how it goes,

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 18, 2018, 11:02:27 AM
Hey Rob, I agree with every piece of advice from Glort, however he missed one thing(not like him), I would be looking at the piston ring gap.

Didn't Miss it, never even occurred!

Good pickup Bob!
With a bit of luck, it might be that simple and easy to fix.

When I used to do hi performance 2 Strokes, I used to like to use " filebacks" for rings. These were oversize rings that you Filed the gap back to that you wanted. You could get real trick and file the ends back at an angle so they over lapped and gave even better sealing.  Never had a problem with them heating up and sticking, maybe I put more clearance than I realised. :0(

I marvel at modern engines with just one tiny thin ring even on 4 Strokes.  Probably explains why they only last 20 hours and you have to replace the rings.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 18, 2018, 11:45:55 AM
Hey Glort, used to do similar stuff with Cord over sized rings in the UK, my thing at the time was Mini Cooper engines. Had a few seize after a few minutes because we went too tight on the rings. Had a lot of fun with those simple engines, miss the reliability, simplicity and cheap parts.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 18, 2018, 12:07:42 PM
I SEE NOW, THERE ARE MORE RESPONSES. I'LL ANSWER THEM RIGHT AWAY.

Thanks, Glort, for your quick reply.
Ha, you meant seizing, instead of siezing. Yes, it gets jammed.

Cooling.
There's no water cooling. It's air cooled. I'll attach a movie of an identical engine, that I found online.
https://www.youtube.com/watch?v=TxLd4O31AMY

As also that movie shows, after just two minutes of running stationary, no such engine will get jammed for overheating, even if the air cooling system isn't attached, as was also the case when I had my test runs. Do you agree, or am I mistaken? Before it was never a problem.
After two minutes running I could still touch the cylinder fans, without getting burned. But the engine was slowing down and getting jammed.

Oil supply pipe. Seems OK.
Oil does flow to the rockers of the valves. When I turned the flywheel by hand (feet, actually), and the oil supply pipe not yet attached to the cylinder heads, I saw oil was coming out at the top side of the pipe.

Oil between cylinder and piston. Seems OK.
When I had already taken the cylinder heads off, after the second jamming, to check if there was any visible damage, and then turned the flywheel by hand, I saw the cylinder wall got oil.
I'm not sure where the cylinder gets the oil from, by the way. Does it come, partly, from the oil of the valve rockers through the valve of the air inlet, or does it just splash up, from the carter, against the bottom side of the pistons and cylinder, as I read somewhere?

New pistons, slightly different from old ones.
The new pistons have fewer of those little holes for the oil to go through. The engine workshop guy says these holes are to drain off the oil, while I thought they're meant bring the oil to the cylinder wall, after it splashed up against the bottom of the pistons.
In any case, turned by hand, the pistons and cylinder wall show to get oiled.

Oil pressure. Don't know (yet)
I don't have a meter for that. But I know the oil is supplied to the valve rockers.

Bearings getting oil?.
The bearings of the pistons at the crankshaft, right?
Hm, I hope I never have to get in there, that far. Do they get oil through the crankshaft itself, or from oil splashing up? I don't have a manual of this particular engine.

"check the barrels are round and square to the block"
You mean the cylinders, right?

Barrels square to the block.
What could cause them not being attached square to the block?
When I bolted the cylinders back on the block, 6 nuts per cylinder, I took care of bolting nut 1 and 4, then 2 and 5, then 3 and 6, building up the force used in 4 phases.
But maybe the gaskets that are placed under the cylinder make one cylinder tilt a tiny bitty?
Somehow, one of the pistons doesn't reach the same height as the other one, and therefor, to get even compression, one cylinder gets a stack of gaskets under it, and the other one just one, a fraction of a millimeter thick.
Maybe that stack of 5 super thin gaskets causes a problem? Maybe some dirty under it, that I overlooked, makes a barrel tilt a tiny bit? Because tilting is what you mean, not?
What had surprised me, is that one of the (identical!) pistons didn't reach the same height to the cylinder head. What could be the cause? And earlier fixing of a problem that was before my time? Anyway, I decided the bump clearance should be equal, and therefor I took some gaskets away there and put them under the other barrel. The bump clearance is about 1 mm, now, as seems ideal for an almost similar Petter. When turned, the cylinders seem to have equal compression (very hard to get over it, pushing the flywheel with the feet) and when the engine is started, the seem to do fine, both cylinders fire and the cylinders get equally hot (felt by hand).

So, when I take the engine apart again, I'll check these gaskets and if anything would be there that make a barrel tilt.

Check the barrels are round.
OK, I will find a way to do that.

Piston clearance.
The manual of an almost similar Lister-engine "type LD" says the clearance should be no less than 0.005", being 0.127mm. BUt this is what I need  the right manual for...
Now I wonder, what did the guys of the workshop use as reference, then? I know they don't have that manual either. They surely didn't know what the bump clearance of this particular engine should be.
The new pistons definitely had a lesser clearance than the old ones, but I found that logical, for the old ones, and the barrels had been worn out.
But when I was putting the honed barrels back over the pistons, I was already worried about one not going in so well. Both of the pistons would lift the heavy cylinders up along their long bolts, when I turned the flywheel. No sliding. With oil, no sliding either. When I told the workshop guys about one piston needing more force, they said it was not unusual. Which I found strange, because it shows a difference that you don't want there to be, right? But they're the professionals, and they sometimes shake their heads when I talk with them, obviously not knowing the right terminology, the right names of the engine parts (I earlier had them check the fuel injectors, when I started with bringing this engine back to life 4 years ago, by cleaning the pipes).

When you say, the engine revision workshop guys may have 'botched' it, it is the first thing that came into my mind, when I was putting the engine back together and one piston clearance seeming so cramped.

Oil scraper ring. One more problematic.
One of the pistons went back in the barrel with more difficulty, especially for the scraper ring at the bottom. That needed some work to get it in. Different from the other piston. A second time that I took it all apart and back together, same thing happened.
Could that cause this engine getting jammed after a few minutes idle running?

Clearance again
I'll go confront the workshop with the clearance problem, again, then and ask them what measure they applied.

Glort, I'll be happy with some more of your thoughts about it all.

Cheers
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 18, 2018, 12:28:06 PM
Hey Rob, every symptom you have posted suggests that the piston rings do not have sufficient gap. It`s an easy fix but takes a little time. Much better an engine that is a little tight than one that is too loose before it`s done any work.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 18, 2018, 12:51:40 PM
[quote author=ajaffa1
"If the gap is too small, file or grind the end of the ring until they are within specification. Do this for every piston ring and then reassemble. The problem should be solved."

Hi Bob,
oh, that'd be great, if that would be all. As I wrote as a reply to Glort, one scraper ring seems to be problematic, and also the second time I worked it into the cylinder.
These rings came with the pistons from Lister-Petter. Could they put the wrong rings on it, then? But how do I know "If the gap is too small"? I haven't found the manual for this thing yet. Is there a way to calculate it?

Anyway, I'm happy to hear that such a small thing could indeed jam that robust engine.
So, I happy to have found some guys at this forum who are really helping, and not speak technical 'chinese' to me leaving me puzzled about what the h*** they mean.

One of the bolts connecting the oil supply pipe to the cylinder head (to the valve rockers) appears to be a wrong one, slightly off size, too short, wrong thread, and when I bolted it back in, not yet knowing that, it decided to end it's working life (the thread got too damaged), so I need to find me one of have it made, before I can start the engine again. That will be somewhere next week I hope.

Glort and Bob, thanks!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 18, 2018, 01:13:11 PM
Hi Rob, there is sure to be a formula for working out what the correct gap should be, sadly I don`t know what that is. If you post the diameter of your pistons I am sure that someone like Dieselgman or 38ac will give you that information.

I am also a little concerned that you don`t have the same bump clearance on both cylinders, please check out how to set this correctly on the WOK at the top of the home page, courtesy of 38ac.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 18, 2018, 02:06:20 PM

I don't see anything " Normal" about the pistons fitting the bores different.  They should all be the same size so why would one be noticeably Different to the Other?

When You pull the engine down I would take the rings off and see how the pistons fit and measure the clearance.  There may be a tolerance difference but not so much that one piston actually Binds.

As for lifting the Cylinders when Fitting the pistons, yes, that is not unusual but if it did it without the rings fitted, I'd be very wary of that.
The difference in piston height in the bores I also think is a concern.  Could be a bunch of things,  Deck heights not right, uneven piston heights, different rod lengths.... Again none of these things good or what you want.

You have a difficulty here in it seems you assembled the engine and the workshop did the machining. I would expect if they did the lot they would have checked things like ring gap and  piston heights and corrected them properly.
You don't need a manual for everything. Many things on engines are roughly the same and close enough is good enough and you know when something is not right.  For an engine that size, any Engine, I certainly wouldn't want a piston tighter than 5 thou and that sounds pretty tight to me.  On the skirt I'd be thinking at least 10 thou or more.  For the ring gap, it varies with which ring generally but something around 10 thou would be common.  It does depend on the ring type as well.

I doubt the oil ring would be causing the problem unless it has no gap because that shouldn't get very hot like the compression rings and expand that much but then again, if it has no gap....  Unfortunately this is all stuff that should have been checked as the engine was re assembled.
The holes in the piston should not be critical. The rings are generaly scrapers so are in fact drain holes.
One thing I always do on engines I assemble is to put a 2mm chamfer on the piston bottom edge. This allows the piston to ride up on the oil film and get between the piston and the bore instead of the lip scraping the oil away and there being no oil film between the 2.  The oil rings are to control the oil film so you do not want the piston skirt taking it all away before hand.

If the thing has been seizing  repeatedly, The bore may now be scuffed or scratched.  I'd be giving it a Close look over and probably running a hone through them  anyway just to make sure there are no high points now. If the ring gaps are too tight, you can almost guarantee they will have dug in and put scratches in the bore.  The gap is where the rings will try to push out the most and have the sharpest corners.  Something I always file a bevel on as well so the ends won't scratch if they are not pinned and can come round the thrust side of the engine.   Depends how deep any scratches are but if they are bad enough, the proper practice would be to go back to the start and hone the bores again and put in oversize pistons and rings.
  Again, depends on what you find and how critical a duty the engine has to do. You can get away with a lot if the engine is more for play but if it's going to do work you need to rely on, at best you will have an engine that probably goes through a bit of oil.

Depending what you find, it may be worth having the engine re assembled by the engine shop so they can check and set all these things.  If they don't do a lot of diesels, I'd be taking it to one that does because they will probably have a good idea off the top of their heads what the numbers should be in the ballpark of.  They don't vary all that much from similar engine to another.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 18, 2018, 02:22:09 PM
I am also a little concerned that you don`t have the same bump clearance on both cylinders, please check out how to set this correctly on the WOK at the top of the home page, courtesy of 38ac.

Hi Bob, but I wrote I had adjusted the bump clearances. They are the same now by putting more gaskets under one cylinder. I did that after I saw that one piston didn't reach as high as the other one. Somewhere further down there must be something that creates a 1 mm difference. This engine has been worked on before I got it. It shows at various spots.
Cheers
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 18, 2018, 02:25:55 PM
Hi Rob, there is sure to be a formula for working out what the correct gap should be, sadly I don`t know what that is. If you post the diameter of your pistons I am sure that someone like Dieselgman or 38ac will give you that information.

Diameter of pistons: 99.6mm = 3.9212598425"
I've contacted dieselgman.

Thanks
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 18, 2018, 11:52:37 PM
Hey Rob, When you fitted the new pistons did you fit new small end bushes (wrist pin bushes in the USA)? generally these are made of bronze and are pressed into place. They require reaming afterwards. If the machine shop reamed these out of square the piston will bind at the top one side and at the bottom on the other. When you checked the bump stop did you use two identical length pieces of lead, one either side of the piston above the gudgeon pin. The two pieces should measure the same thickness after performing the bump. If they do not then the bush is out of square.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 19, 2018, 01:31:29 AM

Hi Bob, but I wrote I had adjusted the bump clearances. They are the same now by putting more gaskets under one cylinder.

You shouldn't have to do that, it is really bit of a band aid solution.  Packing anything with multiple gaskets where there is not meant to be to take up dodgy tolerances is never a good practice. All the heights should have been checked as things went along.  The cylinders for instance should have been checked they were the same height and machined if they were not. I would hope the machine shop did that but they might have done as asked and nothing more and if not asked in the first place..... same as the pistons, rods  and normally the crank throw out would be as well. Bob found his bearings were out when he did his engine. It starts at the beginning and goes from there.

I think this is a concern that the engine has been put together without these basic and fundamental things done.
Unfortunately you can't ever assume things fit together right because they are new or refurbished.  There are tolerances for a start. Everything has a margin of this to that rather than one specific. If it is within the range then it's good. The thing is on occasion, all the margins go to one side instead of balancing.  If the bore is tight and the pistons are large and the ring s are a fraction oversize..... it all adds up to a tight engine that could cause problems you are seeing.  you really need to pull it all down and check everything to see where the problem lies.

It could be none of the things we have suggested. It's not easy to diagnose things when you can't see them and only relying on the info you are given. Possibly one look at the engine would make the problem obvious, maybe not but there is nothing like seeing and playing with something yourself same as not actually being able to see what the engine does when it stops.

I have often found the shortcut to problems is doing things the long way.  There is every possibility you may have more than one problem so pulling the engine apart and starting from scratch may in fact be the quickest and easiest fix.  Start with you bump Clearance and find why that's different.  are the Cylinders 1mm different? if so then you can get that fixed. maybe the pistons are different heights in the crown, are the clearances OK or is one far too tight? What ARE the ring gaps, is the bore still OK or does it need re machining now?..... so it goes.  If the cylinder heights are out and the Ring gaps too tight then you have fixed both things.

Also, if you don't have a manual, how did you determine and what did you set the rocker clearances at?  Won't have any effect on the problem but it's a measurement that needs to be set for best performance.  10-12 Thou would be ballpark on these too but just wondering how they were set and where the number came from?

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: 38ac on October 19, 2018, 03:18:18 AM
The bump clearance on a PJ is indeed set via the number of and various thickness of the base gaskets which are actually steel shims. As I remember three different thickness are available to be used in combination as needed. That being said 1mm is a LOT or variance. Much more than,would be seen normally and can be due to issues that are not readily apparent. From what I have read on this thread you need to put down the tools until you have a manual. A person can feel his way through a simple overhaul but when an engine has suffered previously in unknown ways all that can be accomplished by me from a distance is to throw darts at it. One possibility that will not be in a manual is that the shop that honed your cylinders did not use a fixture that simulates being installed on an engine. The bores are pulled around by the clamping forces thus A cylinder that is made round while not clamped will not be round when installed.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: 38ac on October 19, 2018, 09:54:32 AM
Thought I should add that "genuine" Lister Petter parts does not mean what it once did. The current owners of that mark are sourcing parts from India along with selling old stocks. They claim higher standards are applied but I have two experiences that dictate otherwise.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 19, 2018, 09:59:31 AM
Thought I should add that "genuine" Lister Petter parts does not mean what it once did. The current owners of that mark are sourcing parts from India along with selling old stocks. They claim higher standards are applied but I have two experiences that dictate otherwise.

So often the way now.  So many things come from the cheapest source and are simply re branded and marked up for manufacturers while the no names sell the exact same thing and are labeled Chinese crap because they are sold cheaper.
 
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: 38ac on October 19, 2018, 10:59:41 AM
It is not hard to understand why the parts are currently being out sourced if one is aware of the former pricing structure. Prices were not simply high, they were totally insane and a lot of L-P engines were scrapped because of it.  Dont get me wrong, I applaud the effort to supply parts at a reasonable cost which seems to require sourcing said parts from the 3rd world.  I just dont like the fact they hide behind the legendary L-P quality while stuffing green and red boxes with parts made in India with (seemingly) no more quality control than any other supplier.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 19, 2018, 11:52:01 AM

Here in Oz they are selling Chinese knockoff generators and I think it was pumps with the LP branding and painted green.

They are about as LP as I am but they are still priced to kill especially when the next ad down on fleabay is the same thing in another colour and 1/3rd the cost. They may not be bad units but they sure as hell are not anything other than the typical Chinese clone unit.

Having some experience with the things, I consider them the entry level machine.  The horizontal Cyl Chinese engines IMHO are superior and then you go to the proper Jap engines like yanmar and Kubota and the euros like Ruggerini, Lombardi and others.  I can't split them but the base Chinese engines to me are only better than the Crap petrol engines like Briggs and Tecumseh.
Kawasaki, Subaru/ Robin, Yamaha and of course Honda all are vastly better than the other 2. Most of them do diesels as well but I have not had my hands on any as yet.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 19, 2018, 12:16:05 PM


Just came across this Vid which explains how to do rings gaps which may be helpful for new engine builders.

https://www.youtube.com/watch?v=gs0Fg3tvhoc
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 19, 2018, 01:16:14 PM
Dear Glort and 38ac,

when I noticed the difference in the height reached by the pistons, I went to search for the cause and measured all details of the cylinders and the pistons, over and over again, and then there was not other conclusion to draw than the piston rods, or maybe the way they're attached to the crankshaft made the difference. I really didn't feel like going into the block, to avoid "fixing a thing that isn't broken", when I saw, with the shims I could adjust it. It may not have been a 1mm difference but 0,6mm, btw. Sorry for that. Taking shims away from one cylinder and adding them to the other doubles the effect. The measure for the bump clearance I copied from a manual of an almost equal Lister engine. The same for the inlet and exhaust valves.
I've just contacted the Petter specialist Jim Perkins in the UK for a manual of this engine, that he says he has.

For me, "taking the engine to a company that will fix it" is not an option. It's 300 lb and it sits in the boat. I have to be careful with my spending, it's a hobby to change this 10 meter life boat into a holiday home, do all the carpenting myself, and try do it all with that old engine still in it. I've made great trips, of months, had great party's on board, but if the fixing of the engine is going to cost a lot, I'd rather get me second hand more modern one that's a bit more sophisticated. This one doesn't even has anything to attach a start engine to and cranking it, to start it, is that heavy (a guy taller and stronger than me could just do it, and be exhausted after), that I made a construction with a scooter's engine doing the cranking, to get the flywheel turning with the speed needed to let the decompression handles go. Though that may seem complicated, it starts the Petter within 6 seconds.

Next monday I'll take the thing apart again, and follow all you guys' instructions and tips. And I may have the proper instruction book in my hands as well.

Thanks all so far!
Cheers,
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 19, 2018, 01:26:31 PM
Hey Rob, When you fitted the new pistons did you fit new small end bushes (wrist pin bushes in the USA)? generally these are made of bronze and are pressed into place. They require reaming afterwards. If the machine shop reamed these out of square the piston will bind at the top one side and at the bottom on the other. When you checked the bump stop did you use two identical length pieces of lead, one either side of the piston above the gudgeon pin. The two pieces should measure the same thickness after performing the bump. If they do not then the bush is out of square.

Bob

Hi Bob
no I didn't do any of that. The engine sits in a boat. Since the pins of the pistons were such a tight fit, I didn't suspect anything worn out, there. It's me who removed the cylinders and the pistons (hammered the pin out with a wooden same size 'pin' in between). I brought them to the engine shop, and had them find and order the new pistons, hone the cylinders, after which I picked them up and did the reassembling.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 19, 2018, 01:35:19 PM


Just came across this Vid which explains how to do rings gaps which may be helpful for new engine builders.

https://www.youtube.com/watch?v=gs0Fg3tvhoc

That's a video about fire arms, Glort!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 19, 2018, 02:19:59 PM

Ah, so it is!
Great Vid though! I'll take a Dozen of each of those and a crate of ammo to go with them!  :0)

The more mundane but appropriate vid is here:

https://www.youtube.com/watch?v=_gyv-xtG51M

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: dieselgman on October 19, 2018, 06:00:30 PM
PJ1 and PJ2 ring end gap  .029 to .037 inch
bump clearance .036 to .042
bore 3.8175 to 3.8185 inch

dieselgman
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 20, 2018, 02:12:52 AM

Pretty wide gap! Almost 1mm at the far end.
If the rings were tight, this would certainly explain the Seizing. More expansion there than I would have given credit for especially in that size bore which isn't even 4".

  I'll be the piston clearances are pretty generous as well.  Hopefully the gaps weren't installed on the thrust side of the bore otherwise there will be scoring for sure.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 21, 2018, 08:39:50 PM
PJ1 and PJ2 ring end gap  .029 to .037 inch
bump clearance .036 to .042
bore 3.8175 to 3.8185 inch

dieselgman

Thanks, dieselgman, for these exact numbers!
I'm happy to see that the present bump clearance of my PJ2 engine is exactly in the middle of the two numbers you gave.
Coming tuesday I'll have the time to check the rest.
Cheers,
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 22, 2018, 12:25:10 AM

Will be interesting to hear what you find!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 22, 2018, 09:56:56 AM
Hey Rob, Glort is right as usual ( I hate him,  :laugh: ). There is a chance of scoring in the bores, it is very unlikely to be severe. Do you have a cylinder honing tool? They are not expensive and can usually be purchased at you local automart or tool store. They fit into an electric drill, give the cylinders a quick hone to remove any scoring/high spots. Then wash out any residue with soap and water, please be diligent in doing this as metal particles and carborundum have no place in a cylinder or engine.

Adjust the ring gap and reassemble, all should be good. Recommend using flushing oil when doing the first oil change, I also recommend that you do the first oil change at half the running time stated in the manual.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 22, 2018, 10:36:21 AM

Lucky you can take the barrels off this engine. If you couldn't it would have to come out to clean it after you honed it because there would be no way to get all the grit out of the sump in a boat. If you se a line ( or several) run your fingernail across them and see if you can feel them.  If you can, will definitely need a hone, if you can't.... probably OK.  I used to run 2 strokes with all kinds of marked bores and they were fine. The speed they run at means there is not much time for blow by and other things and they are a bit inefficient anyway in their gas flows but there is an awful lot you can get away with in 2 strokes that diesels are probably more particular with.

More I think about this the more I think Bob nailed it.  If the engine shop sourced the pistons and did the bores, they would set the clearances to match unless they really stuffed up. It would be automatically assumed that the person assembling the engine would check and set the rings gaps.
Kinda why it slipped my mind, it would never occur to me that they would be put in without checking.  Bit like putting a head on without a gasket.

Given the gaps are so wide on these engines, it's almost an odds on bet they would be way too tight from the factory, the fact the engine locks up so quick makes sense it would be the rings because they would heat up first from the friction alone and as soon as the piston swelled.  Ouch!

How many times have you run the thing when it locked up? Was it ever under load or making any power as in above idle?
Locking up an engine like that is a mechanical cringe fest.  Hopefully nothing bad has happened.

When you take the thing apart, I would try to lift the cylinders just enough to stuff rag over the top of the block so nothing can fall in the sump before you liberate the piston from the bore.   It's possible you may have snapped a ring which would  still likley be in place given the tight clearances ( you'd sure want to hope it is!) but may drop out into the sump when you pull the piston out. Probably better not to have bits of hard metal ring floating round in the sump or wasting hours trying to find and remove it.

Also you will probably want new head gaskets as well.  May be able to re use them but i'd be putting in new ones anyway.  Last thing you will need is to be pulling the thing down again or chasing some problem related to that. Shims may be re-usable but check. 1MM is a Lot to be padding out with shims/ gaskets.

Hope it goes well.
Be interesting to see some pics of the rings in the bore, the insides of the bores and the piston walls.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 22, 2018, 12:32:15 PM
Does anyone have a tip for the best way to remove the piston rings? I'd of course do it extremely careful, but I don't know what I don't know. The scraper ring has a spring in the gap. Would that thing cause a problem?
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 22, 2018, 12:42:40 PM
How many times have you run the thing when it locked up? Was it ever under load or making any power as in above idle?
Locking up an engine like that is a mechanical cringe fest.  Hopefully nothing bad has happened.

Also you will probably want new head gaskets as well. 

Hi Glort
I ran the engine a few times with no load. The first time it stopped itself after 2 minutes. The second time, I stopped it when it slowed down. The third time I had it run as slow as possible, no load. It then slowed down after 9-10 minutes so I turned it off. After each time it was impossible to turn the flywheel by hand, for like a minute or two.

The head gaskets I cut from material with metal thread in it, especially made for the hottest parts of an engine. Don't know the name of it. It's been awhile that I bought it. But yes, I'll cut new ones.

I'm very curious to see what the ring gaps are, tomorrow!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 22, 2018, 02:09:09 PM

The rings are removed as they say in the classics, Reverse of installation.
You just carefully spread them and ease them over the top ( or bottom) of the piston. You can put something thin like feeler gauges between the rings and piston and slip them over that way but as long as you open the part where  the gap is and ease that up and over you should be right. just be careful and try to spring them as little as you can.  I normally lift one end and then work the ring around till it pops off but see what feels best.  Just go slow and gentle.

It sounds like the damage may not be significant. Lot different to having the thing working hard and welding itself together.
I have no experience with engines locking up this way. Normally it is lack of oil or overheating or they become one in the same.

You have the best chance of getting out of this as easy as possible which is good.

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 23, 2018, 05:28:11 PM
PJ1 and PJ2 ring end gap  .029 to .037 inch
bump clearance .036 to .042
bore 3.8175 to 3.8185 inch

dieselgman

Hey dieselgman, I just measured the gaps of the first pistons' rings, when taken from the piston and put into the cylinder at the top side, and that was a bit over 0,4 mm, less than 0,45 mm being around 0,0165 inches.
(Photo attached to next post)
So, then indeed, the gaps are too small. They'd need double the size.

It means that ajaffa1 was spot on with his first comment!

Now shit happened. I still broke the 4th ring, the scraper ring. Dang! Got a bit confident I guess after the first three went OK. So, I'll see if Jim Perkins has one for me, part from the manual and an oil banjo bolt (replacing a wrong one put in by the life boat's former mechanic) he'll mail to me.
I still have the old pistons with intact rings, but they're a fraction thinner. I guess, worn a bit. What you think, guys? Would that indeed be a cause a problem?

I also see the tiniest vertical scratches, all the way down, in the wall of the first cylinder I just removed. How would I know which scratch is severe enough to demand new honing? And what if a second honing means a tinier wider cylinder, for the same pistons?

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 23, 2018, 06:02:26 PM

If you se a line ( or several) run your fingernail across them and see if you can feel them.  If you can, will definitely need a hone, if you can't.... probably OK.

Be interesting to see some pics of the rings in the bore, the insides of the bores and the piston walls.

Hi Glort,
I now see you already gave an instruction to see if the scratches caused by too cramped piston rings are a problem. Most of them I can not feel with the nail. One I felt, though. I'll check again, all around.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 23, 2018, 07:34:40 PM

Yep, Bob is a clever fella with a nose for potential problems.  I don't think too many people would have picked that one up straight off the bat!

So far you are very lucky.  Hopefully the other Bore is just as undamaged.

As far as using the old rings, it would seem likley that they overbored the cylinders when they did them and the pistons are also larger. You'll need to know what size they went over. Generally the first oversize is  5 thou. If this is what they did which is likley, You'll need to tell the guy you are ordering the broken ring from. You won't be able to fit an old ring if the thing has been over bored.  Have a look at the pistons. They may have something like +.005 stamped in the crown. Might also be .010 if the bores were heavily scored or worn to start with.

When you rebuilt the engine, Did you do any of the bearings or just the top end? Also, did you get the specs for the head bolts and torque them down with a tension wrench in the correct order to the right specs? If not, best you do this time.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 23, 2018, 08:10:11 PM
As far as using the old rings, it would seem likley that they overbored the cylinders when they did them and the pistons are also larger. You'll need to know what size they went over.

When you rebuilt the engine, Did you do any of the bearings or just the top end? Also, did you get the specs for the head bolts and torque them down with a tension wrench in the correct order to the right specs? If not, best you do this time.

Ah, yes, of course. The engine revision guys said they'd order slightly bigger pistons, because of the honing.

I didn't do any bearings. I took the cylinders off, and removed the pistons. Nothing else.

And with the reassembly I followed instructions for how to bolt in the right order as I wrote earlier. No 'force meter', but an instruction of how the force used should feel/ I don't have all the specialists' tools.

I MAY BUY ME ONE, though, after reading about the importance of it (protecting the gaskets).

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 23, 2018, 08:40:12 PM

Have a look at the pistons. They may have something like +.005 stamped in the crown. Might also be .010 if the bores were heavily scored or worn to start with.

The new pistons say 020 at their top side.... I guess that's 0.020 inch extra, then.
The old pistons have "196695  S" engraved, there. Now what can that mean?
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 23, 2018, 10:34:02 PM

New Pistons are  20 thou over. Old rings definitely won't fit that large.
The old pistons probably just have the part number on them.  The S could be part of the part number or stand for something like Standard Compression.

You might want to feel the Rods and make sure there is no freeplay in the bearings. If there is any detectable movement especially in the big end, You'll want to do those as well whether it's a big job or not. Otherwise you could do damage and be pulling the whole thing down again anyway pretty soon.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 23, 2018, 10:44:53 PM
You might want to feel the Rods and make sure there is no freeplay in the bearings. If there is any detectable movement especially in the big end, You'll want to do those as well whether it's a big job or not. Otherwise you could do damage and be pulling the whole thing down again anyway pretty soon.

You're not making me happy with this... I expect horizontal movement to be not a problem (even a necessity). Vertical it would be problematic. Before I did not feel any vertical freeplay, when I checked it for that purpose.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 23, 2018, 11:27:01 PM
Hey Rob, looks like you may have dodged a bullet if the scoring is only very minor. A cylinder honing tool should fix the problem without having to do another re-bore. A tool like this is cheaply available in the UK https://www.ebay.co.uk/itm/CAR-ENGINE-CYLINDER-BRAKE-HONE-BORE-HONING-FLEXI-SHAFT-TOOL-51MM-TO-178MM/222367752202?epid=1146057264&hash=item33c626a00a:g:Ur8AAOSw2xRYbWnC:rk:3:pf:0

I know the purists are going to start throwing spanners at me for recommending such a low tech solution but you are only trying to knock the high spots of the scoring.

After honing clean the cylinders and then clean them again! (detergent and water and lots of clean rags) Now check the piston ring gaps and adjust as needed.

If you contact the machine shop that provided the pistons, their supplier should be able to send out a replacement piston ring. Might be worth asking for a complete set in case you break any more during assembly.

Glort is right about checking for play in the big end bearings, does your engine have a crankcase door? If it does then the cost of a new gasket and a pair of white metal bearing shells is a no brainer.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on October 24, 2018, 12:37:29 AM
Greattings to all

Sometimes I feel the same as Rob, but the guys around here have a long-standing experience - that's what I call masters.

I'm afraid the workshop where Rob had the job done knows less about it than he does.

As we say - a problem never comes alone! and maybe they've seen the bottom of Rob's pocket.

And also, as I had already said: "the machine works as it wants and not as we wish!"

Of course sometimes we doubt what our eyes are seeing, but the engine starts to take its weight in gold! and that does not cheer anyone.

Rob, dismantle the whole engine and resemble it again, each step makes sure that the whole assembly rotates freely - attention to the clearences because the engine heats up.

I'm sure it will get better!

Cheers
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 24, 2018, 01:14:02 AM

I know the purists are going to start throwing spanners at me for recommending such a low tech solution but you are only trying to knock the high spots of the scoring.

Dunno about that Bob. I don't think it's the low tech solution, I think it's the right solution.
Bores have just been done, it's only a bit of light scuffing... so far.  To bore them again and have to go to more new pistons and rings would be I think idiotic.
Like you said, run the hone round to knock off any high spots and that's it.  Not an F1 or Aircraft engine being built here.  :laugh:

Rob have you got the other piston out yet and have you also checked the pistons for signs of scuffing? I doubt now the pistons will be too tight BUT, I also don't know what effect having the rings so tight and jamming may cause as well.

Have to laugh at the description of the Hone.... BRAKE hone...... 51mm to...... 51 MM would be some BIIIG arse brake Cylinders! Maybe if you are working on Terex Mining trucks but...... Hmm. Then again, if you were working on anything with a 7" bore at the other end of their capacity...

RR Merlin was only 5.4".  Maybe for a ship engine 7" would be handy..... and then it would be the right tool for the brake Cylinders on them as well!   
Oh, ... wait.... Never mind!  :laugh:

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 24, 2018, 08:10:31 AM
Now I'm confused. In a catalogue in Dutch, the "schraper-veer", which, to me, seemed the Dutch word for scraper ring, is not the one I thought it was.

The one I broke was the 4th one, at the bottom side of the piston. It hides a spiral in it, that goes all around the piston and it has horizontal slits in its side. The Dutch catalogue has another name for it, with the word for "oil" in it.

What's its proper name in English, for the bottom ring that I broke?

Jim Perkins says he may have one, the plus .020 size. He's going to send me some stuff anyway. Otherwise I contact the online lister-petter shop.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 24, 2018, 10:10:15 AM

The bottom ring is often called the oil ring or the oil control ring.  The scraper ring is generally the 2nd ring down although may be the 3rd if there are 2 compression rings. It's usually tapered ( although might be hard to see) and also helps control the oil on the bore for the Compression rings and to steady the piston in the bore and keep it centred.

The oil rings are  hollow or have slots cut in for the oil to pass through and go back to the sump through the holes in the piston.

The extra piece behind the oil ring is the expanded. It's job is to help the oil ring exert more force on the Cylinder wall as the oil ring is supposed to have the greatest force on the bore of all the rings.
The top ring especially is helped to be forced against the bore by the combustion/ compression getting behind it and helping force it out but that doesn't happen with the oil ring which is the lowest on the piston.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 24, 2018, 03:41:15 PM

Hi guys!
This video shows a honing tool. I knew it was something like that, but would this size be OK for my bigger cylinders?
https://youtu.be/-NRUZNX0IAg?t=642
Indeed, I'm not going to buy new pistons. They were expensive: 245 euro each. But I could do some light honing, to just get that one hardly noticeable scratch away, right?

I took both cylinders off, with the finger nail I can detect just one light scratch. Other lines are visible but I can't feel them, and I'm quite a sensitive guy, really ;-)! Most of my working hours so far were spent on illustration and design.

I let the pistons sitting on their rods and the crankshaft. There's really no vertical 'play' of the pistons. All the pistons can do is move sideways, over the pins they're attached to the rods with. The rods can not tilt one bit. I see no reason to dig into the block and take it all apart.

I got all other rings off the pistons without breaking any. Did that with sliding them up over three thin metal strips, one of them being a valve clearance feeler gauge.

I'll wait for the manual to arrive in the mail (and stuff) before adjusting the gap of the piston rings. The manual I was using so far, of a one cylinder air cooled Lister LD, actually had measures of the gaps equal to the ones of the new piston rings.

I'll ad the flyer for this engine (earlier I wrote it weighed 300 lb, but that's in kilos. It weighs 611 lb).
I also ad a photo of the boat it sits in, parked in an Amsterdam canal. It was an open life boat coming from a cruise ship. I build the cabin over it. Last summer I painted the black figures at the white hull. The wooden roof part and windows can be taken all off in 2 minutes. There it also has a fire place in it, for wood fire, oh yes! So, that's why I need this engine to work again. I missed 3 months of boating fun already!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 24, 2018, 10:41:33 PM
Hey Rob, honing tools come in different sizes for different size bores. Look on fleabay for one that will adjust to at least four inch. They also generally come with different abrasive heads, coarse, medium and fine.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 25, 2018, 09:07:31 PM
Hey Rob, honing tools come in different sizes for different size bores. Look on fleabay for one that will adjust to at least four inch. They also generally come with different abrasive heads, coarse, medium and fine.

Bob


Hi Bob, today I mail-ordered the proper honing tool with the proper 'sanding stones', honing oil, a piston ring opener, a 'tension wrench' that can handle the in the manual described force for the cylinder head bolts, and some more delicacies from the tool candy shop.
Before all that arrives, there's plenty to do: draining the oil from the block and cleaning it, cutting new gaskets, checking the shims or making a new one with the desired thickness.
And when Jim Perkin's package arrives with the manual, operation handbook, oil banjo bolts (one put in my engine wasn't properly fitting!) and two piston + .020 oil rings, I bet I'm going to have an interesting week after this weekend!

Here's the monster in the state I got it in, in 2011 (here without air cooling cover). It took me three years before I dared touch it. But all it needed for its first start was cleaning the fuel pipes (and a scooter engine to get the flywheel turning with enough speed).
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Matt12 on October 26, 2018, 01:41:24 AM
Hi Rob,
            I'm a newby to this forum but am an ex motor mechanic, (retired).
Did you notice any scars on the piston skirts, assuming they are alloy pistons, if so, the pistons are 'grabbing' the bores, due to insufficient clearance, if not, then it's likely the top rings are too tight, ( too little end gap), this gap should in your case be around 4 thou per inch of bore, 4x4 = 16 thou.
Hope you have a successful outcome.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 26, 2018, 12:01:39 PM
Hi Rob,
            I'm a newby to this forum but am an ex motor mechanic, (retired).
Did you notice any scars on the piston skirts, assuming they are alloy pistons, if so, the pistons are 'grabbing' the bores, due to insufficient clearance, if not, then it's likely the top rings are too tight, ( too little end gap), this gap should in your case be around 4 thou per inch of bore, 4x4 = 16 thou.
Hope you have a successful outcome.

Hi Matt,
thanks for the extra info. I'll check for scars at the pistons, today. But the 16 thou may not be correct, at least not for this particular engine, as earlier written by dieselgman. According to his data is has to be like double that distance. The Petter engine collector Jim Perkins says the same. He'll snail-mail me the manual today.
When pushed the rings into the cylinder for about 2 inches, the gap is only 0.3 mm, which is 0.118 inch. According to the proper manual for this engine (PetterPJ2) it should be 3 times that.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 26, 2018, 02:24:12 PM

Have you got both cylinders off and checked the gaps of both lots of rings yet?

If so what were the gaps on each one with each ring?  Did you measure piston Clearance.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 26, 2018, 02:31:49 PM

Have you got both cylinders off and checked the gaps of both lots of rings yet?

If so what were the gaps on each one with each ring?  Did you measure piston Clearance.

Hi Glort
yes but I'd already written so. at the top pf the cylinder the ring gaps are 0.4 mm. But 2 inch lower the gaps are just 0.3 mm (0.118 inch). All rings the same.

The piston clearance is around 0.3 mm (piston, when I had it lowered in cylinder, pushed to one side, feeler gauge at other side).
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 26, 2018, 03:18:55 PM

OK, thanks. must have missed that.

About the only thing I can't relate to in metric is clearances.  Thou, not a problem. .4mm?? NFI what that looks like.  :embarassed:
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 26, 2018, 03:46:47 PM
You can't be that helpless, Glort! I have to do it all the time, go from mm to silly inches...
Here's a tool
https://www.rapidtables.com/convert/length/mm-to-inch.html
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 27, 2018, 05:22:26 PM
Hi Rob,
            I'm a newby to this forum but am an ex motor mechanic, (retired).
Did you notice any scars on the piston skirts, assuming they are alloy pistons, if so, the pistons are 'grabbing' the bores, due to insufficient clearance, if not, then it's likely the top rings are too tight, ( too little end gap), this gap should in your case be around 4 thou per inch of bore, 4x4 = 16 thou.
Hope you have a successful outcome.

Hi Matt,
i can't believe I hadn't noticed it yet, but indeed, one piston is clearly damaged in four places at its skirt. The other one a tiny little bit, but hardly.

So, then I thought, is it the cylinder, or is it the piston? I measured the clearances, at the top.
Piston 1 had 0.3 mm, piston 2 had 0.4 mm clearance.
Then I had the cylinders change place.
Piston 1 had 0.3 mm (0.0118"), piston 2 had 0.4 mm (.0157") clearance....
Meaning: the pistons aren't exactly of the same size, right? Not at the top, at least.

In inches, the measured difference between the pistons' diameters would be 0.0039".

Your suggestion and Glort's very first response (and my own in my 'opening speech', but that more due to not being hindered by any other knowledge) that the clearance between pistons and cylinder might not be enough, seems to be correct.
That fits to the picture of the damage.

Two inches down from the top, the clearance is about 75% of that at the very top of the cylinder, I noticed when I measured the ring gaps at the top (0.4 mm) of the cylinder, and further down (0,3 mm).

I'm not happy with these traces at the piston skirt, can you imagine...
I have to wait for the manual Jim Perkins sends me to see what the clearance should be.

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: mikenash on October 27, 2018, 08:15:26 PM
Rob - quite a long way back in this thread you said that you had been supplied with oversized pistons because the cylinders had been honed.  When I read that I assumed you meant the cylinders had been bored to an oversize and you were just speaking casually. 

But, reading your comment re the piston skirts, I wonder if the cylinder has been bored correctly to suit the oversize pistons.  Do you know?

Just checking . . .

Cheers, Mike
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 27, 2018, 10:39:04 PM

So, then I thought, is it the cylinder, or is it the piston? I measured the clearances, at the top.
Piston 1 had 0.3 mm, piston 2 had 0.4 mm clearance.
Then I had the cylinders change place.
Piston 1 had 0.3 mm (0.0118"), piston 2 had 0.4 mm (.0157") clearance....
Meaning: the pistons aren't exactly of the same size, right? Not at the top, at least.

Be aware that pistons are not round, they are in fact ovalised.  This is to allow  for heat expansion.  You could get very different readings  depending on where you measure the clearance.  If you measure it on the wide side obviously going to be different to if you meausre it on the narrow side that is allowed for expansion.

I also suggested you check the pistons a while back because I did not know what potential effects having the rings bind would be, but I could imagine the possibility of the pistons being rocked sideways as the force of the rods tried to make them go where they didn't want to.

Sorry to say but there seems to be a LOT going wrong here.  Perhaps it is time to call in an experience mechanic and have things looked at and you may be wise and save money in the long run having them re assemble the thing for you.  I think if you are going to have any need for reliability on this thing, It would be a very smart move to at least have an experience eye look it all over for you.  There could very well be other problems in the making that you are not aware of now.

Clearly your skill set is in other places which is fine, we all are experts in some things and not so much in others.  Not gapping the rings was a huge oversight and potentially very expensive. I know you like anyone else does not want to part with any more money than you have to, but I think the investment in an experience person may save a lot of money  at best and give you good peace of mind at a Minimum. As you have seen, as straight forward as an engine is, there is a bit more to it than just meccano where you put the bits back in place in order.

I hope your pistons are OK but if they are not, the cost of replacing them will probably make the cost of a mechanic the cheaper option straight up. In my experience as limited as it is around marina's, there is always a knowledgeable mechanic  hanging round some where so start having a look at places close by and see whom you can turn up.  At very least they can tell you if the machine work has been done correctly or not so you know which way to go.
Also having an experienced and knowledgeable person argue any warranty work will give you infinately better chance of getting somewhere and eliminate the chances of you getting baffeled with bullshit and fobbed off.

I really think the problem is going to be your own than theirs but in any case, you are in a very bad position now having put the engine back together your self incorrectly.  Have it at least checked out by someone in the know and find out about them putting it back together for you so you have some peace of mind there won't be any more problems down the river as it were.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 27, 2018, 11:42:06 PM
Rob - quite a long way back in this thread you said that you had been supplied with oversized pistons because the cylinders had been honed.  When I read that I assumed you meant the cylinders had been bored to an oversize and you were just speaking casually. 
But, reading your comment re the piston skirts, I wonder if the cylinder has been bored correctly to suit the oversize pistons.  Do you know?
Just checking . . .
Cheers, Mike

Hi Mike,
I had brought the engine revision shop the old piston that had little pieces broken off, and the two, scratched cylinders, and had them do what they had suggested: find a supplier of new, slightly wider pistons for this particular engine (given the type, model and engine number) and hone the cylinders accordingly.

When I later picked up the new pistons and honed cylinders, how could I expect the clearance then to be not OK? It was their suggestion to do it like that, and their job to do that right, wasn't?

I don't think I did anything wrong, with the reassembly, or it was that it didn't come up in my mind, that I should find a way to check if they'd done the job right.
I think... but correct me when I'm wrong.

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 28, 2018, 01:43:52 AM

To me, checking clearances and Gapping rings would be as fundamental and basic as putting gaskets in. Mechanic that workd for my father is always saying and PROVING, " Just because it's new, Don't mean it's good". Yes, the engine re conditioners should have made sure the clearances were right and this is why YOU need to check them.  In the end, the responsibility ALWAYS lies with the guy assembling  the engine not the guy that supplied the parts. Anything wrong should be picked up during the build. I'm not trying to give you some highbrow industry rules or culture here, it's really just the way it is and logic.


The fact you weren't aware of checking clearances is why I think it would be a real good investment  to have someone look things over for you to make sure there are not any other problems you might be missing that will save you much more money to take care of now rather than later.

Sometimes the ultimate shortcut is not to take any at all and go the long and through way round.  :)
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 28, 2018, 12:30:55 PM
Yes, the engine re conditioners should have made sure the clearances were right and this is why YOU need to check them.  In the end, the responsibility ALWAYS lies with the guy assembling  the engine not the guy that supplied the parts. Anything wrong should be picked up during the build.

ASSEMBLY GUY's FAULT...
Dang, that's what I once told a publisher who had the emailed LOW RESolution example of my illustration printed on a book cover, instead of the high res, sent on a CD together with the typography and the design. 2000 books were printed with low res cover, not showing the fine details I'd put in. I said the production leader screwed up, for not noticing the mistake, that those who assembled it, had made. So, I get the point you make.

But still, what were the honing guys thinking?
When the engine seized after the first two tests, I wrote them an email about it, asking them what could have made the engine seize. All they replied with was: "A pity it didn't work out as we'd planned".

OVAL shaped PISTONS, or not?
I've also been measuring and measuring, over and over again, both the old pistons and if there's a difference between the longer and the shorter diameter of the oval, it's not more than 0.05 mm, which is 0.00197 inch, roughly 0.002".
The Lister LD manual I have doesn't say anything about the oval shape, when measuring the piston clearance doing maintenance. It just says: "measure it, it should be not less than this".
Could it be, that with these old engines, the oval shape wasn't yet invented, or that it isn't applied for every engine? Or is the 0.00197 inch difference in length and width of the oval shape about the expected margin?

DAMAGE TO PISTON
Here's a picture of the damage to Piston 1. It has similar damage at the opposite side. The grooves rubbed off, here.
Piston 2 has tiny traces of damage. The grooves still there, and all around.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on October 28, 2018, 10:15:03 PM
Hey Rob, pistons should be round and the sides should be parallel. The cylinder bores should also be round and the the same size all the way up the bore. The manual should tell you what the correct clearance between the piston and the cylinder should be. Some pistons have a mark on them indicating which way they are to be fitted, this is usually because the gudgeon pin (wrist pin) is slightly offset in the piston.

The wear on the piston in the photograph suggests that the piston is not round and that the clearance with the cylinder wall is too small. Alternatively the cylinder walls are not parallel. Take them back to the shop that did the work and shout at them until they put it right.

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 29, 2018, 11:52:50 AM
Hey Rob, pistons should be round and the sides should be parallel. The cylinder bores should also be round and the the same size all the way up the bore. The manual should tell you what the correct clearance between the piston and the cylinder should be. Some pistons have a mark on them indicating which way they are to be fitted, this is usually because the gudgeon pin (wrist pin) is slightly offset in the piston.

The wear on the piston in the photograph suggests that the piston is not round and that the clearance with the cylinder wall is too small. Alternatively the cylinder walls are not parallel. Take them back to the shop that did the work and shout at them until they put it right.

Bob

Hi Bob
you might encounter a dispute with the other guys here about the possible oval and parallel shape of pistons in general. I've read there are even barrel shaped pistons, and the oval shape would be normal when the piston is cold. It would get round when heating up. It's all about fractions of mm. When I measure the old pistons, the difference in length and with of the oval would be no more than 0.05 mm (roughly 0.002"), as written earlier.
The Lister LD manual, of a 1 cylinder engine, does mention the  direction of the pistons and says it would show the right positioning by the word "Camshaftside" on it.
My old-, nor the new pistons mention any such thing and do not show a mark, or sign. It only shows a number.
When I look into the bottom side of one of the old pistons, I see a tiny desaxation. It could be as little as the thickness of a penny, or even half of that. It goes to the side of where also the number is written at the piston's top.
I understand the function the desaxation (now that I've read about it).
I may have put the new pistons in wrong, both of them with the number at the other side. But could that have resulted in seizing after two minutes running stationairy without load?

I'm waiting for the better manual to be dropped in my mailbox, that's being sent by Jim Perkins from the UK.
It's a pity he had to tell me its a manual of a slighty different model, still... hm. I'll know how 'slightly' when I have it in my hands and see the illustrations.

I wait for that, study the book, before I dare go back to the engine renovation garage to show them what happened. I bought the honing tool and oil, but if honing needs to be done, I may still have them do it.

And yes, I will consult an expert, Matt!

There's one more unusual thing, with this engine: one injector has 4 spraying holes, the other one only three. This was discovered when I had them tested. For the rest, they're identical.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 29, 2018, 02:13:23 PM
I'm not sure I have any helpful advise left.
Good Luck with it.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on October 29, 2018, 04:31:42 PM
Hey Rob

Cheer up!

Unmount everything until the last piece, rebore cylinder to next oversize (or get new standards), fit new pistons (send damaged ones to recycle to get some pennies to help buying new ones).

I'll get there, with more acurate patience, and more burned eyelashes.

Think of the new pistons as less of a headache pill you did not spend at the pharmacy.

Don't forget its your boat engine, it must be reliable.

Thumbs up!
BR
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 29, 2018, 05:41:19 PM
Holding back again Glort! You should say what you think
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: mikenash on October 29, 2018, 05:47:58 PM
Holding back again Glort! You should say what you think

Yes.  Man turns to the forum for some advice and support and gets this.  Dickhead
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 29, 2018, 06:11:33 PM
Glort

I'm of the opinion that your reply is rude, indeed, as you suspected, but then, you didn't care.
Your remark about the level of embarrassment is way out of line. You fill in for others too quickly. I'm very embarrassed. Still, I want to be honest.

To answer to your concern about the injectors.
This is how I got the engine. Understanding that three holes may deliver fuel different than four holes, I measured the delivered fuel of each, by letting turn on the start engine, and let the fuel be spit into two of those thin laboratory glasses, that make measuring liquids easier. I did that over and over again, and adjusted the delivery of the two fuel pumps according to it.

Pistons not reaching the same height.
This is how I got the engine. One of the pistons rods is a fraction shorter than the other, as I had guessed it was. It has nothing to do with the bearings. The rods aren't exactly equal. Noticing the difference, I took the shims, that were there when I got the engine, away, there, and put them under the other cylinder, to equal the bump clearances, and with the cylinder head gaskest, that I cut from material especially made for cylinder head gaskets, that I only do not remember the name of, because I bought it years ago, from a shop for Classics and old timers, after which they were exactly right, according dieselgmans notes.
I've been endlessly measuring the bump clearance in all kind of ways, to get to the 1 mm, and I was happy to see the engine fire at the first attempt, the two cylinders responding the same way, with equal force, and the cylinders warming up equally, as never happened before.

Suspecting the pistons to be slightly different
I had been measuring the pistons sitting in the cylinders and came to the conclusion they've not exactly the same diameter. I had measured them at different spots. My main conclusion was: they're different.
Well, THEY ARE. But why?
Now that I took the cylinders and pistons all off, again, and slide the pistons through the cylinders (WITHOUT THE RINGS), one immediately feels a difference. Piston 1 has to be pushed, doesn't like to go through, but will with a continuous push. Piston 2 slides through easily.
For Piston one, I can not imagine it expanding a bit through heat and then still going through. It seems to have its maximum width already.
Now I am aware there could be a reason for piston 1: it's damaged by the seizing. May be it got deformed, but....

But let me tell you:
BEFORE ANY TEST RUN a POSSIBLE PROBLEM WAS NOTICED by me, with THAT PISTON!
When I put the new pistons in the very first time, when I reassembled the pistons and cylinders I noticed getting piston 1 into the cylinder was more difficult than piston 2. And I told the engine revision garage right away. When turning the flywheel, piston 1 would lift the heavy cylinder up. Remember, they said it was "not unusual". They had said this happens sometimes when they assemble engines and they didn't think much of it. They had actually said sometimes force is needed to get a piston in, while another pitons easily slides in into the cylinder next to it. For me THEY were the specialists that I thought I had to trust, for them doing this work day in day out.
I think my suspicion was more right than their denial.

Blame?
I have already written about this, but when I called them about the problem of the broken piston, it was THEM, the specialists, telling me what they could do for me: bring the pistons, and the cylinders and we have a look.
I went there. They said: We'll measure the things, check things out, and you pay 40 euro for that and our advise.
When I came back after a few days they presented me with their idea: because of the scratches in the cylinder wall, we'll have to hone them. We'll search for new, slightly bigger pistons.
And when they found the piston supply shop, they let me know the price for the pistons, the shipping and the honing, and I said OK and then they went to do their specialists thing.
They didn't ask for measures. They gave me the impression they knew what to do and how to do it. Their workplace is a hall full of engines they are fixing (I hope). I earlier had good experience with them.
I don't know how they decided about the measures for the honing, how deep to go, how much the clearance should be. They seemed to know what they were doing!

Did they supply the rings? Yes, they came with the pistons they had ordered.
No, the ring gaps I did not put in the wrong positions. I could figure out all by myself, what was the logical thing to do, there.

If new honing clearly has to be done, then I'll be ready to pay for it again, when they think they have done it right the first time, even when it doesn't seem to have the right clearance.

Glort, thanks for your advises, so far.
You added a whole list of things to check. I have that list already. It's all in the Lister LD manual that I have mentioned a few times.
You forgot one thing: the fuel. That I should put diesel in.

BTW, the tank was loaded with red diesel, when I got the boat. I brought it away. I had to clean the tank anyway. And the fuel pipe. And the filters.

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 29, 2018, 09:11:18 PM
Is it possible that someone had replaced a barrel at some stage in the past? If you switch barrels do the pistons level correctly? Measure the conrods and barrels and see if theres a difference. Glort is a good bloke albeit with a low frustration tolerance.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 29, 2018, 09:39:47 PM
Glort

I'm of the opinion that your reply is rude, indeed, as you suspected, but then, you didn't care.

I apologise.  I really did not mean to be rude and if I was I am sincerely sorry.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 29, 2018, 09:43:02 PM
Glort

I'm of the opinion that your reply is rude, indeed, as you suspected, but then, you didn't care.

I apologise.  I really did not mean to be rude and if I was I am sincerely sorry.

Dripping sarcasm and bitter irony I love it!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 29, 2018, 09:48:35 PM
That's a bit rough.  I was not trying to be sarcastic at all. Just apologise for something I should not have said and my poor judgement in saying it.

Not trying to be an arsehole even if I come across as one.

Rob,
I apologise to you for my rudeness and misplaced Comments. I was out of line.  I am sorry for any insult caused and my lack of decorum. 
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 29, 2018, 09:50:39 PM

Yes.  Man turns to the forum for some advice and support and gets this.  Dickhead

Hey Mike,

I'll be in your part of the world in a fortnights time. 
Why don't we meet up and have a chat?  :laugh:
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 30, 2018, 11:00:36 AM
Is it possible that someone had replaced a barrel at some stage in the past? If you switch barrels do the pistons level correctly? Measure the conrods and barrels and see if theres a difference.

Hi Johndoh
it has become a long thread with lots of text. It says somewhere I measured everything (barrels, pistons) and, together with there not being any freeplay in the piston rods' bearings, I was left with only one conclusion: the piston rods aren't equal, and that's why the pistons don't reach the same height in the barrels. They don't even LOOk equal. There's a slight difference in shape (a light curve in one), though they show the same code, "P57" and a "J" on them.
Now I'd be surprised if someone would say the light curve in that one rod (think of a saber) would have been caused by a mishap. Though, were it straight, it may just reach the same height as the other one... That's one for you, Glort, to add to the list ;-)!

So this engine has definitely been doctored on by a creative mechanic of the ship line it came from (in a life boat). As I wrote earlier one of the two bolts connecting oil banjos to the cylinder heads was wrong as well. A fraction too big and 6 mm shorter than the other one. Thereby damaging it's thread and by the latest re-assembly, causing oil to leak. Therefor I'm waiting for Jim Perkins delivery of an original bolt.
The old pistons weren't equal either. One was original Lister Petter, had this name engraved on it), while other one, the broken one, had only a number engraved.
I see no reason to believe that one of the cylinder barrels were ever replaced. They're identical.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 30, 2018, 11:58:31 AM
I sure understand your frustration, Glort, when you observe this guy, me, treating an old Petter as a learning object. I indeed thought that taking the thing apart and putting it back together in the reverse order would do the job. But what kept me busy was also: what was the cause, or were the causes, of the old piston to break? Why that one piston and not the other one? And that I had to check whatever could be checked, like
- equal fuel delivery
- fuel injection timing
- oil supply, oil leaks
- type of oil
- compression
- valves
- exhaust pipe
It was noticeable, due to the blue smoke, that there was a problem there, before this shit happened. A friend, very experienced in renovating classic cars and engines, helped me adjust the valves. I talked about the blue smoke to the owner of the oldest oil shop in town, having all the various oils for the old classic engines, and he suggested I should try thicker oil, for the engine having worn out. There was logic in it, so I did. Using the thicker oil may have been wrong, for being a possible cause for even quicker overheating.
While on a long boating trip, the engine had severely overheated, and seized, when the air cooling had been accidentally blocked and I had not seen it, steering at the front of the boat.
Since then, the engine kept heating up quicker, and the exhaust smoking more (and blue). I needed 9 hours of boating to get the boat home, which I did in steps, altered with cooling periods. And then one cylinder showed to be overheating extremely fast, making it clear there was a mayor problem in there. And then I found that one piston being broken.
And that's when I got my confrontation with the unexpected fine details of the Zen of Diesel Engine Assembly...
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 30, 2018, 05:28:54 PM
Was there any rust or water in the cylinder or sump? conrods arent easy to bend in service usually hydro-locking is the cause in my experience. You'll have to start at the beginning with 2 equal conrods and machined bores. 
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 31, 2018, 01:54:52 AM
Was there any rust or water in the cylinder or sump? conrods arent easy to bend in service usually hydro-locking is the cause in my experience. You'll have to start at the beginning with 2 equal conrods and machined bores.

Hi Johndoh
Water in the cylinder? Not that I know. Not in my time, at least. By me, the engine was always used in a dry place.
https://www.carthrottle.com/post/how-can-hydrolocking-occur-and-why-is-it-a-potential-engine-killer/
When I see the pictures of the bent piston rods at this webpage, mine is just very slightly bent. Not as bad as any of the examples there. As I wrote before, it results in a difference of only 1 mm in length. It even looks like it's made like that. But a bent rod, just to connect two points in this engine, doesn't make sense. So it's bent by some accident. Jeee. When, and by what, I have no idea. The piston that sat on it, was not the broken one. I guess it was bent somewhere in the 40 years before I had it.

The more I learn about this engine, the more I feel like selling it as scrap and getting me an other one built in!

Thanks for the tip!
Cheers
Rob

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 31, 2018, 04:42:40 AM
The more I learn about this engine, the more I feel like selling it as scrap and getting me an other one built in!

That may well be the smartest option. You should be able to get more than scrap for it I would think.  Slap it back together and sell it as needing a rebuild.

It would be unwise in the extreme to rebuild the engine with a bent rod. That is just asking for more problems waiting to happen. The geometry of the throw will be out and that could lead to  Thrusts and forces on the piston and other places in the engine that are not meant to be there.
 The new piston that was scuffed and chipped, was that attached to this rod by any chance?  Could be the rod is no longer clearing the piston skirt properly at BDC.

If you are going to replace the rod, you would be unwise not to rebuild the bottom end while you are at it.  Being in a boat there is a good chance the engine will have to come out to remove the rod and install a new one anyway.

If you take the engine out, replacing it with a newer, smaller, lighter water cooled unit would have many benefits.
Water cooling would be quieter for a start and if you live on the boat you could use the cooling water for heating the Boat and even showering if it has one.

Kubota, Yanmar and Isuzu all do small water cooled engines and your other option which may be cheaper is to fit a small car diesel like out of a Golf or similar. These would be easier to get parts for and I believe in Europe Diesel car engines can be had quite cheap.  You'll just want to find one with a manual rather than electronic Pump.  You would undoubtedly get much more power, probably better economy, have a smoother engine and it would weigh no more.

There would be a lot of other aircooled designs that are more up to date as well. Ruggerini, Lombardini, hatz, Deutz and others should be pretty plentiful in your part of the world and are all excellent engines. maybe you could even get a Chinese Yanmar clone.  Available in any HP and configuration you want up to about 30 HP. Very tough and reliable engines although not too quiet. Come in water and air cooled flavors.

As a matter of interest, How is the engine compartment air Circulated on your boat?  Does it just have big Vents on the deck that push air through with the movement of the craft of is there some sort of fan forcing air through?
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 31, 2018, 08:30:09 AM
A VW 1.9 diesel indirect injection engine can be got here for about 50.00 Wiring consists of the starter wire and the wire for the cut off solenoid. In a car they return north of 50 MPG. These are simple engines to work on too and are water cooled. They idle about 850 RPM have about 68 HP and a load of torque. They aren't governed like a stationary engine but I bet glort is right it would work in a boat. (might need an electric fan in a confined space)
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 31, 2018, 09:36:33 AM
The more I learn about this engine, the more I feel like selling it as scrap and getting me an other one built in!

 The new piston that was scuffed and chipped, was that attached to this rod by any chance?

If you take the engine out, replacing it with a newer, smaller, lighter water cooled unit would have many benefits.
Water cooling would be quieter for a start and if you live on the boat you could use the cooling water for heating the Boat and even showering if it has one.

As a matter of interest, How is the engine compartment air Circulated on your boat?  Does it just have big Vents on the deck that push air through with the movement of the craft of is there some sort of fan forcing air through?


Hi Glort,

the old, broken piston as well as the new, rubbed off piston were on the other rod, not the bent one.

I used to be happy with the air cooling, for it being simpler. A pump less that could malfunction, and less pipes to worry about, like leaking, getting stuffed, freeze, forgetting valves to open or close.
A later project would have been, to give the hot air two options out: one straight out, and one through a system through the boat, for heating.

Since it was just an open life boat, the engine was covered with a fiber glass case, and the fan of the flywheel pressing the air along the cylinders and out at the side. Not a place where you wanted to be sitting.
Since I built a cabin over the boat, it couldn't stay like that, and have the hot air fill the cabin, so I made a noise absorbing case around the engine, and built a system that reversed the stream of air, so that it sucked out the hot air through a wide chimney.

There's one problem with new investments in an other fuel driven engine or spending much on this one. Amsterdam wants to forbid having any boats with fuel driven engines and allow electric engines only. First they aimed at 2020 for this rule. But it is being delayed. Till when, we don't know. But the thousands and thousands of boats in the many canals have no loading unit nearby. The boats become worthless. At the same time, the city raised the tax for fuel driven boats to 5 times and makes a lot money from the boats it has criminalized (Like with the cars in London). Maybe that's the reason for the delay: the council counts on the tax revenues it gets from the fuel driven engines and already knows on what great projects (of friends..) to spend it on..
If this law passes, most people will try to sell their boat around the same time and no one will want to buy one...

This is why I thought I have this engine fixed and sell the boat and get me small one (because of the size of it I pay way more tax than I could have envisioned when I bought it, before Amsterdam started to raise the tax 5x) when it may still be possible. I thought it would be harder to sell a boat with a rotten engine.

It may be nice to have an electric engine for short trips through the Amsterdam canals, but not long trips. It makes a lot of boat owners, 99% of whom have their boat in 'their canal' near their home, pissed at the Amsterdam council. It's the destruction of capital. Where would they load the batteries? I now need a cable of 50 meters (over the street) to get from my apt to the battery of my boat, or power the tools. I'm lucky to have it that nearby For the bigger boats the electric engine and batteries cost a lot.
It's the uncertainty of the near future law what's disturbing. Also, as soon as 'everyone has an electric engine, they'll raise the tax for it as high as now for the fuel driven boats!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on October 31, 2018, 10:22:45 AM
Hi Rob

If you change engines do not forget to match the weight of the current engine with the next one, even if it is necessary to add ballast.

It is necessary to keep in mind the laws of archimedes and dynamics.

And yes, an air-cooled gives less problems, especially in the channels that are shallow.

BR
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on October 31, 2018, 11:12:22 AM

I thought it would be harder to sell a boat with a rotten engine.

It sounds like the thing will be worth nothing and you'll have to fire sale it anyway. Whoever does buy it will probably have to replace the engine.
Get it running and sell as is.  Might also be worthwhile looking at what you could get for it now as against what you will have to spend on it to get it going.
Might be better just to take a lesser price and save yourself the headaches.

Then again, if the decision becomes unpopular enough, they may scrap it.

Quote
Also, as soon as 'everyone has an electric engine, they'll raise the tax for it as high as now for the fuel driven boats!

Yep! All this environmental calp trap is nothing but a revenue raiser for Gubbermints and big Biz.

As I have complained before, this whole environmental, green save the planet thing is a complete crock of shit.  My Daughter was in Amsterdam last year and went back again this year. Loves the place and the boats on the canals. All their environmental do good crap will ruin that and they will all disappear and a tradition lost forever. In years to come when the drawbacks of this rush to everything electric wears off they will look back at their mistakes and people will realise they lost a lot and gained nothing.

It's all posturing and feel good crap! I'll bet there are 100 things on the rivers that are causing more pollution and problems than the boats which are ignored.  It's always the same. How do the authorities propose these boats all be charged up?  The Netherlands is still hugely Fossil fueled for it's power generation so where is the benefit? No exhaust from the boats but loads more pouring out the power stations.
I'm not against coal at all, it's being made a scape goat, but I am against bullshit and insults to my intelligence.

If the power supply there was like Norway and 99% Renewable Hydro, yes, they would have a point and I would have to agree with it but when it's all just  a load of crap to get on the green bandwagon and achieve nothing.... It's bullshit.  I spose some of the greenwashed will say you can put solar panels on the boat without having a clue that you'd need to cover a house with them to get any sort of power output practical for the application. Yeah sure, great if you take the thing out once a month  for an hour but if you actually want to go anywhere.....
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: mike90045 on October 31, 2018, 02:34:48 PM
here's a theory concerning a bent rod and a replaced piston:

Starting Fluid (ether)

At some point, someone may have dosed the engine with ether while attempting to start it.   The ether fired, the engine broke a piston and bent a rod.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: dieselspanner on October 31, 2018, 09:29:35 PM
+1 for the bent rod being caused by a lung full of 'Angels Breath'

I've got an old Mccormick that had been well abused, when I pulled it apart one of the main bearing caps was broken in two, it had to have been the huge amounts ether (Start Pilot, ect)

I rebuilt it farmyard style, not having line boring kit I 'machined' the hump off the cap with an angle grinder and made a 'strongback' out of 1" square bar and bolted the bugger down as hard as I dare with plenty of Loctite to fill the gaps and lock the threads, 3 summers on and she's still holding together.......

As for the vehicle engine in a boat, I put a Perkins Prima, 2 liter DI from a small van (Meastro) in a 14 ton, 45' Dutch barge and it performed faultlessly for 9 years.

Non turbo and using the original water pump to circulate the cooling water through 20 meters of 2" pipe as a keel cooler, it was great. The only mod I had to make was having the prop re pitched a whole lot finer, the Perkins wanted to rev a bit more freely than the Merc unit it replaced.

As for the 'New Diesel Free Regulations' could you get away with having the boat as a hybrid?
Leave the diesel motor where it is and belt drive the prop shaft with a DC motor with the gearbox in neutral (assuming you have a 'box that will tolerate it, some have the lube pump driven off the input side) . When you run the diesel engine the motor could be used to recharge the batteries or you could run the diesel motor as a generator to charge the batteries (using a very small bank - who's going to legislate?) and propel the boat with the electric motor, keeping within the letter of the law, if not the spirit. After all you only need to leave the 'exclusion zone' and then you can return to the original system.

Cheers
Stef

Cheers Stef
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 31, 2018, 10:51:04 PM
here's a theory concerning a bent rod and a replaced piston:

Starting Fluid (ether)

At some point, someone may have dosed the engine with ether while attempting to start it.   The ether fired, the engine broke a piston and bent a rod.

Smart!
Yep, the guy who sold me the boat started the engine a few times for me, with start spray. I never used it, because I then read one shouldn't.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on October 31, 2018, 11:10:06 PM
It sounds like the thing will be worth nothing and you'll have to fire sale it anyway. Whoever does buy it will probably have to replace the engine.
Get it running and sell as is.  Might also be worthwhile looking at what you could get for it now as against what you will have to spend on it to get it going.
Might be better just to take a lesser price and save yourself the headaches.

I saw that there are two Lister Petter part resellers in The Netherlands, that sell also the old stuff.
Now I think,

Plan A could be: go with the slightly bent rod and guess it won't break, since it hasn't done so yet in 4 years, get me a new piston again, and hone the barrels according what the manual will say.
Or get me a new rod as well, if it's not too expensive and when I can put it in while the engine stays where it is. The block has doors on either side, I think I can reach the nuts of the rod on either side.

Plan B: maybe I should take the hole bloody monster apart, as the job for the winter, check all details, clean it all, and see if I discover the cause of it being too hard to start by cranking it by hand (without start pilot, as the dealer who sold me the boat did!), and, if its worth it, rebuild it all and make it look gorgious and function well.

I wish Perkin's shipment would be delivered (the manual especially!)
I'll keep you guys posted!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on October 31, 2018, 11:44:16 PM
I think the barrels will need rebored rather than honed. As for the rod it will affect compression and possibly make the engine run poorly, a bent conrod is a weakened conrod. A new conrod isn't too expensive. You may need to check the valves to make sure they are sealing properly and are in serviceable condition. From experience there really aren't any shortcuts to get the engine running right, but it would be worth it.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: mike90045 on November 01, 2018, 12:22:48 AM
What is the availability of BioDiesel and using it to avoid the Tax ?
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on November 01, 2018, 12:47:57 AM

Are you planning to keep the thing short or long term or intend to sell it?
If you want to sell it for something smaller then I'd be spending the least money to get it going and put it towards the new boat. If it's running or Completely rebuilt, I don't see the price you will get being all that different.

I thought about the Train alternative ( Engine> generator> electric motor) but I figured the do gooders have decreed fossil fuels as the devils work and would have Kyboshed that as well.

Maybe Rob needs to get a hold of the specifics of the proposed stupidity to see if that or the biofuels idea is within loopholes he can exploit and what the wording of the proposal actually is.

mate and I have had a Pact for some years now. Either one of us Comes into money we are going to build ourselves a gas turbine Driven jet boat.
Nothing like the smell of Jet-A1 in the morning or the coolest engine startup sound in the world. Might even be able to run it on a Veg oil blend?
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 01, 2018, 08:33:01 AM
Hi you all

Amsterdam just doesn't want any engine that smokes. No hybrids either! Not even two engines (electric for city use, fuel for out going trips) That's what they'd announced, earlier. Actually they want to get rid of all the private boats, so you should always hire one for a canal trip. Everything commercial. They do gooders seem to envision a Disney Park. Indeed, Amsterdam would not be Amsterdam anymore! If there's anything I like, it is taking pictures of all the crazy boats. Nowhere as colorful a collection as here!

Electric cars can load the batteries at the border of town, where diesel generators standing next to the loading units, produce the electricity...
Biodiesel is already standard. And then we have to put a drop of extreme poison in it to kill the bio, to not let it stuff the pipes...

I've tried to separate from my boat earlier, but it's also my darling, that I love and sometimes hate. It's also my floating garden house, in front of my place, and a guest room for two. Hard to decide. But getting the engine to start by hand, which is now too difficult, is where I'd love to get.

The valves are really OK. To turn flywheel with valves closed is a hard job. I need two feet at the flywheel to get it over the compression.
I'll investigate the costs of a proper renovation. And be happy to use all you guys knowledge.

Johndoh
why you think the barrels need a new bore? To keep the barrel walls perfectly straight, maybe?

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Johndoh on November 01, 2018, 08:50:48 AM
I thought you fitted over-size pistons and rings? 5 or 10 thou is a lot of metal to hone off if the pistons are oversize.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: ajaffa1 on November 01, 2018, 09:15:17 AM
Hey Rob, when I read your earlier posts I assumed that a re-bore was what you had done. The way this works is: you measure the wear in the bore. Oversize pistons generally come in increments of +.010 inches. If the wear is less than .010 inch you re-bore to allow for a +.010 piston. The cylinder is then honed to provide a key for the new piston rings and very small groves/indents for the oil to sit in to lubricate the new piston rings.

If what your engineers have done is to hone a cylinder out without a re-bore and then try to fit an over sized piston they should be shot for criminal incompetence.

Very sorry to hear the Dutch government have joined in with the all pervasive green stupidity. Could you find a mooring outside of Amsterdam, so you can continue you passion without being robbed by the taxman?

Bob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on November 01, 2018, 09:17:11 AM
I thought you fitted over-size pistons and rings? 5 or 10 thou is a lot of metal to hone off if the pistons are oversize.

It's a HUGE amount to do with a hone. And..... you would NEVER be able to keep the barrels straight and true with an engine hone no matter if you set it up in a drill press or whatever. They would be wide in the middle and narrow at the ends guaranteed.  Definitely needs to be done on the proper machine by an expert.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 01, 2018, 02:05:53 PM
I thought you fitted over-size pistons and rings? 5 or 10 thou is a lot of metal to hone off if the pistons are oversize.

What about 20 thou... as +020 are the new pistons. But it was that engine specalists plan to do it like that, and they carried it out, so they said. If you look back in the posts, there are all the details about this.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 01, 2018, 02:16:40 PM
It's a HUGE amount to do with a hone. And..... you would NEVER be able to keep the barrels straight and true with an engine hone no matter if you set it up in a drill press or whatever. They would be wide in the middle and narrow at the ends guaranteed.  Definitely needs to be done on the proper machine by an expert.

They talked about honing  and I think, indeed, the barrels aren perfectly straight, because that one piston that does seem a fraction larger (or deformed), when I push it through the barrels, the resistance is not equal everywhere.

And sure, that's exactly what I thought about honing. They way it's described, "never have the stones go out of the barrel" means everything away fro the ends of the barrel will be touched by the stones more than the ends.

So, Glort, I should go there and...
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: glort on November 01, 2018, 02:35:20 PM
The 20+ thou should be the original bore plus 2o Thousandths of an inch to get to the right size.
That size should allow for the required clearances as well.  Normally they would check the piston size, whatever it was then bore  to allow 1-2 though MAYBE for honeing/ final finishing and check that was over size enough to allow clearance for the piston fitted.

Maybe your guys got the numbers wrong, only bored and didn't do the final finishing, the pistons they got were from another similar engine and were 20 thou over that engines bore not yours or...... who knows?

Thing is whatever the size, the pistons should have had the required clearance in the finished bore whatever size that was and then the rings would also be ajusted to their gap even if the bore was not 100% to spec.
As the pistons and rings were very tight, the only conclusion can be the bores were not finished to the proper size for the pistons supplied.

If you are going to get a new Piston(s)  get them first and see how they fit. Might just turn out they do fit the bores correctly.  The finished size is not as important as it being correct clearance  for the pistons fitted.

 If you have any intentions of keeping the boat and running it for more than a few hours DO get a new rod. When you change the rod, put new bearings in.... both big ends. they will probably only come as a set anyway.  You do need to check the clearances on those as well and tightening the big end caps with a tension wrench is CRITICAL.  Install bearings, torque them down with a plastigauge or similar in place, unbolt, check clearance, if OK, put something like cam assembly lube in the bearings, reassemble and torque Down.

Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 01, 2018, 03:23:20 PM
I wait for the manual t be delivered, look at the advised clearance, then check it with the one OK piston, and then see.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on November 23, 2018, 02:16:33 PM
Hi Rob

How things are going with your JP2?

BR
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 23, 2018, 02:31:03 PM
I've sent the engine workshop who bought the pistons and did the honing the info from the manual, about the exact measurements for the cylinder for a +020 piston and asked if they'd want to take a look into it all being right, and do another measuring, when I'd bring the stuff over. I also asked where they'd bought the new pistons because I wasn't all that happy with them being different from the originals at various points and that I considered doing some shopping again. I didn't mention any blame. Just the things as they are: I have these questions.

10 days later, still no response.

I got very busy with other stuff, though.
The plan, now, is to contact the two resellers of Lister Petter parts and see if they have pistons that look more, like the originals, preferably, identical!

I have ONE question, that I do not find the answer to in the manual: what the clearance should be between the piston skirt and the barrel!

Cheers
Rob
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on November 23, 2018, 02:33:54 PM
I understand I may find the exact measures of the barrel and that of a piston, and then deduct and find the clearance.
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on November 23, 2018, 04:46:53 PM
Hi Rob

see may thread (reply 131 >>): http://listerengine.com/smf/index.php?topic=8320.msg97563#new, and pay attention to 38AC's notes.

BR
Pedrosa
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on December 04, 2018, 12:04:54 PM
Hi Rob

No news, good news, or not so?

BR
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: sirpedrosa on December 20, 2018, 07:03:11 PM
Hi Rob

How things are going with your JP2? Any improvement?

BR
VP
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: Rob PetterPJ2 on April 23, 2019, 10:11:52 PM
Hi guys,

I'm sorry I didn't reply to your questions for an update, but just recently I picked up the project again, and I think I have some good news. Jee, 120 days have past...

When Jim Perkins, from the UK, had sent me a copy of the Petter PJ2 manual, he had somehow overlooked that many pages were missing. Something I first noticed when I couldn't find certain info in it.
Anyway, he has then sent me a complete copy.
But I just kept measuring and measuring the cylinders and the pistons and tried to find out, to what degree the cylinders needed to be bored or honed again, in a friends garage, but I kept being insecure about it. The manual didn't and doesn't mention the ideal piston clearance, or margin it should stay within, anywhere! It just kept me puzzled too much.
First when the cold of the winter left us, it became tempting again to occupy myself with this boat engine. SO, I had to decide what to do.

Now, the good news is, that, with a friend, Jack, who had worked in a garage, and knew more about repairing engines than I, I took the stuff back to the engine revision workplace and simply asked them: "Can you just look at it, measure the cylinders and pistons again, and see what could have gone wrong and what can be done to get it fixed?"
And the guy of the shop, Mike, did measurements right away. He saw there were slight differences in the cylinders they had honed 4 months ago. He did accept the possibility that the pistons they had bought for me were maybe not such good quality as I acknowledged that I had screwed up by not knowing I had to adapt the piston ring gap myself according to a manual that I then didn't yet have.
They were very busy but they would see what they could do. This Mike called me a week later and said they fixed the stuff as good as possible. The cylinders were honed 0,02 mm more (about 0,008" is that?) and the damage on the pistons was polished away a bit. Not ideal, but buying all new stuff again was not the option I'd go for.
There was no bill attached.

So, I went back to the boat with the engine sitting in it, and was then thinking about that slightly bent connecting rod... I was advized to not keep that one there. I apparently thought it would have been quite a job to get the rod out, but I could reach the two bolts from the already open side of the engine and it took me just about 20 minutes to get it out.
My friend Jack said it could be bent back by a professional. I took it to the same engine revision shop, but Mike said it can't be bent back. On internet I also saw it's 'not done'. It would be stupid. OK, new problem...
I called a spare part supplier in The Netherlands. They didn't have it.
Then I tried Jim Perkins, this evening. Sent him an email, and, YES, he has the connecting rod and a new bearing and he has already shipped it to me!

So, I hope soon to have put the engine back together. I don't know how long the not so good pistons will do the job. I think of selling the boat, or move it out of Amsterdam, because, again, the city wants to raise the tax and thinks of doubling it! The past years the city said they raised the taxes (x5!!!) because 'fossil' fuel engines are bad for the climate. Now they want to raise the taxes because they need the money to maintain the canals and the bridges!
Title: Re: New pistons Petter PJ2, block after short time engine running. Clearance?
Post by: buickanddeere on May 01, 2019, 04:55:39 AM
As previously stated by numerous others, probably too right on the ring gap.
 As for your skill using the English Language? Superior to the majority of persons born speaking English as their native tongue .