Author Topic: Lovson 20-2  (Read 168653 times)

okiezeke

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Lovson 20-2
« on: January 06, 2007, 10:54:39 PM »
Hi, folks,  as I've commented a time or two I'm the happy owner of a shiny new Lovson 20-2.  This engine will, I hope, be my primary off grid power source for my mountaintop farm in eastern Oklahoma.  I'm not a mechanic, machinest, engineer, and have no financial interest in any listeroid related business.  I'm a 59 year old good ol boy who does my own routine maintenance on my trucks(and bulldozer), and I own the basic hand and power tools that any DIYer would have.  So, I am not an expert in anything to do with diesel engines and am totally open to all comments and suggestions.
       So, here I am with this huge crate in my garage.  We drove to Dallas yesterday and picked it up from the folks at generator depot USA.  The unloading was uneventful with some 2" oak planks and a come-along directly into the garage.  The first thing I did was look into the sump,  where I found clean amber oil with the usual amount of grit, sand, and cast iron fragments.  Even tho the Lovson web site assured me the engine would be clean inside, I was not too suprised.  I've dis-assembled the engine down to the crankshaft--further work will have to wait till monday when I can get a piece of 1/2" steel to make a gib key puller.  So far, I;ve found:
1.  a small washer on top of a piston with no apparent damage
2.  Scratched big end bearings
3.  tappet guides that came out by hand.  Is this a problem??
4.  scratched crank surface(under the rod bearing)
5.  braided stainless flex low pressure fuel lines.
6.  a servicable looking fuel tank
7.  the cylinder has a mirror surface,  I think this means I need to hone it??
8.  Tappets with a fairly smooth bearing surface, but the edges are pretty beat up.
9.  a very normal looking fuel filter--I'll probably replace it anyway.
10 every piece that came out of the engine looked dirty and had a gritty feel.
11. minor surface rust on many parts.

In summary, no big suprises-except the washer!
I'll let you know how it goes with the rest of the tear-down.
Zeke

 
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger

BruceM

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Re: Lovson 20-2
« Reply #1 on: January 06, 2007, 11:16:23 PM »
Zeke, glad you had a visible tell tale of the grit. When you inspect the liner closely, you may see that there are still a very few deep scratches from the original honing.  The bore was then polished by the fine carbide grit- mosty from the pistion machining, just from the brief full load test! (My Metro 6/1 was like this.)

You definately want to disassemble the piston-con rods, as underneath the piston is the home of the very fine abrasive residue that will polish your bore mostly mooth again in 16 hours of running, even with several oil changes AND an oil filter. This is not necessarily visible with the con rod still attached.  This is what happened with my Metro 6/1.  Rumor has it the governor/camshaft covers can also be a repository of some grit, though not in my case.

I would assume that absolutely everything is wrong, until confirmed otherwise; crankshaft to cylinder bore alignment, idler gear lash, play, head clearance, timing, etc. (As well as all the standard stuff in George's great CD.)

Your washer on the piston is a new one.  Good luck on your rebuild project and congrats on your good start. Far easier to do a very diligent job the first time, than to tear it down repeatedly because you assumed that some basic thing were OK. 

Best Wishes,
Bruce

Doug

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Re: Lovson 20-2
« Reply #2 on: January 06, 2007, 11:23:30 PM »
My advice, strip everything and remove every trace of paint, then seal every surface with a semi gloss industrial enamle paint Like Glyptal 1201A ( in spray cans the cheapest way to go ). SCrew the green candy paint job. Use filler and epoxy where you must for a smooth finnish and I'd do the exterior in 1201A as well or a Polymide epoxy soemthing that won't chip and come off in the course of services...

Doug

Technonut

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Re: Lovson 20-2
« Reply #3 on: January 07, 2007, 12:55:12 AM »
I contacted Generator Depot USA to ask about freight charges, and if their Lovsons had any sand and grit in the crankcase. They replied:

Quote
We haven't, to this day, experienced any problem with sand or grit in the crankcase.

That must have been the day before you picked-up yours okiezeke.....  ;)
Metro 6/1 (4 kW Indian GenHead)

GM-90 6/1 (7.5 kW ST GenHead)

Isuzu 3LD1 (12.5 kW Croatian GenHead)

okiezeke

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Re: Lovson 20-2
« Reply #4 on: January 07, 2007, 04:00:58 AM »
I    plan to do the pistons tomorrow.  I'm also going to strip to bare metal.  Just curious tho---  why do we paint the insides of these engines?  I've never seen the inside of any other engine painted.  Thanks for the comments/advice.
Zeke
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger

rmchambers

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Re: Lovson 20-2
« Reply #5 on: January 07, 2007, 04:29:42 AM »
Couple of reasons:

1. It will seal up the metal and anything that you couldn't remove (grit in pockets) will be sealed up and hopefully won't be able to get into the works of the engine and do damage.

2. In the water jacket side of things it will prevent rust which itself will reduce cooling efficiency.

3. It ought to make oil changes easier as well.  Draining the oil should be more complete and when you take the inspection cover off and wipe it down inside you can be assured of getting a lot more of the oil out (along with any other grit or particles you can check for) since you're wiping it off a smooth sealed surface.

Sounds to me that you're doing all the right things in preparation for using the engine.  Good luck with it and post some pictures when you've time.

Robert

Doug

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Re: Lovson 20-2
« Reply #6 on: January 07, 2007, 04:47:47 AM »
Painting a light colour will also let you see what if anything is being shed durring services.

I painted the inside of my spare block to try and keep the rust at bay but this wasn't possible with my other because it was shipped over from India with water in the jacket and I'm scared I'll never get the liner back if I try and it may also never seal again.

I wouldn't paint the liner, but I would clean it with a descaler if there is obvious corrosion like mine and be sure to use clean anti freeze and change it often as needed.

I'm a firm believer in painting the iside surfaces of ever part where practical. I did this in the motors shops when I repair electric motors and gear boxes because it protected the inner meatl surfaces and sealed all the dirt and cuttings I knew I couldn't clean.

It also looks good.

I like the glyptal 1201  ( or 1201A in spray cans ) because its an extremely good bonding semi gloss that doesn't crack and peel, its also very tollerent of heat and oil. But hey its your engine use what ever floats your boat. I shun epoxies but thats because some of thge older ones I used tended to age fast and crack in hot oily enviroments.

If I still worked in a motor shop I might be tempted to heat up engine castings in the oven and give them a hot dip and bake in some good electric motor varnish like PD George. But thats a finnish no roid actualy needs or deserves....

The Palymide epoxies we used on substations seemed good, extremely tough and green for the purist....

Tremclad in green might be just fine too if you give a chance to dry long enough.

Doug 



Doug

okiezeke

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Re: Lovson 20-2
« Reply #7 on: January 07, 2007, 05:11:38 AM »
Thanks again for the info.  All good stuff.  I'm still wondering about the finger tite tappet guides. 
they have light weight brass stampings that hold the guides down to the deck.  I'm sure I could bend these stampings with my bare hands, so they're not very strong.  I've been wondering about replacing the brass stampings with sone 1/4" steel cut  to the same pattern. Overkill???   Thanks for the help.
Zeke
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger

agroot

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Lovson vs JKSON 20/2
« Reply #8 on: January 07, 2007, 12:11:45 PM »
I'm at pretty near the same stage as you are.  My engine is a JKSON 20/2.  One of the GIB keys was cracked halfway through, and the tang broke off when I tried to pull it.  Welding a new tang on it did not work, and I'm in the process of drilling it out.  I'm drilling three holes, two 3/16" holes within ten thou of the keyway, and a 1/4" hole above their centers joining the two.  This should let me break out the GIB key without damaging the shaft.  I'm going this route, as the other key shows it's only held at the edges.

The oil inside was black goo.  I did find metal filings in the crankcase from threading operations for the head studs. I've found no other grit in the engine so far.  The tappet guides were secured by paint.  I used a strap wrench to break the seal.  Once this seal was broken, and the paint removed they were a slip fit.  The Tappet Guide Clamp should be sufficient to hold these in place, as no great mechanical strain is on these parts.

I'm recommending engraving numbers on the counterweights, so that they can be replaced in the same position on the crank.

For a mount, I'm using two rough-cut 6X6 sleepers.  I'm using 4 X 3 X 5/16" angle iron on top, with 3" channel at the ends.  Bolts will be welded to the 4X3 angle to mount the engine and generator. The generator will be mounted on 5/16 plate with 3" channel for additional support underneath.  I'm machining slots in the plate for adjustment.

I bought too big for off-grid use.  A 6/1 would have been sufficient.  My next project will be a 6/1 with dual Xantrex SW5500's running in generator assist / battery charging mode.  This will provide peak power of 11 KW to the home, and a fairly constant load on the engine.  The engine will run 24/7 on WVO.  My 20/2 with the ST-24 will fall to a backup role.  A transfer switch will allow me to connect to the grid in case of illness or injury.

I could start a separate thread, but  I think a comparison of similar engines may be of value.  We both face the same challenges, and will be able to present different solutions.  If you wish, I'll host your images or webpages for this project on my website.




hotater

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Re: Lovson 20-2
« Reply #9 on: January 07, 2007, 02:49:28 PM »
agroot---

It sounds like you're on your way to getting your unit up and running.

One thing I'd caution against is welding the mounting bolt to the frame.  The vibrations   of a Lister frame will soon crack whatever welds are in tension and they're not easy to repair once the engine is mounted.  My advice is to drill all the way through the angle and the sleepers and inlet wash plates into the bottom for bolts.  Ordinary washers will start sinking into the wood once a little oil gets to them.

A drip pan between the engine and the mount is the BEST thing I did with my set-up.   ;)
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

okiezeke

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Re: Lovson 20-2
« Reply #10 on: January 07, 2007, 06:05:34 PM »
Agroot
Good idea joining this thread.  We'll probably both find a lot similar in the process.  I too have wondered if the 20hp is too big to be kept under load 24-7.  One thing I want to do is see how this engine runs at slower rpm, thus reducing hp.  Seems like it will be a long time before I get to that stage.  I have the counterweights set aside in the order I took them out, and will label them.  The good news for the day---the insides of my pistons are perfectly clean--not a hint of grit.  I'll make my gib key puller tomorrow.  Sure hope it works!!
Zeke
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger

SHIPCHIEF

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Re: Lovson 20-2
« Reply #11 on: January 07, 2007, 06:40:56 PM »
Agroot
Put an oil filter in the crankcase door. It will quicky collect any rag lint or other stuff left in during final assembly.
I totally cleaned my crankcase and all the bottom end, including painting the block,  My filter in the crankcase door is showing 'something' a few paint chips, and a slight bit of some black stuff, but nothing is sticking to the magnets! You can see my door filter under SHIPCHIEF in the coppermine gallery, it's made of 30 to the inch stainless screen. Don't make it as big as mine, I can't put the dipstick in. The majority of the oil thrown around inside the engine is not much wider that the big end of the con-rod, so you don't need to make it fit so close to the edges of the door like I did. Nor does the filter have to be complicated. HOTATER made a very simple one that seems to work very well, and he has pictues too. BruceM also has a door filter and some advice.
I didn't think to clean the insides of the pistons. That was brought up in the forum after I put my engine together.
Consider putting bottom rod bearings on the top, and bottom rod bearings on the bottom, use oil dipper tubes. I have the tubes, but put my engine together before the idea of closing off the top oil holes hit the forum. Read about it using the search function.
I think I have a well put together bottom end, but may do a partial disassembly this summer to get caught up on some of the improvements that have come up on the forum, like sealing the head gaskets, measuring the amount the liner sticks up above the cylinder block, cleaning inside the pistons, match weighing pistons and rods, putting bottom rod bearings on top, measuring pre-combustion chamber volume to calculate compression ratio, etc.
Right now I think my engine runs fine, It just powered my whole house during a 4+ day blackout, and the inspections have been fine. Don't get the impression that I think my engine is bad, I just realize (like you) that these are diamonds in the rough.
About engine speed; Mine is rated at 1000 RPM, and it is just starting to hop around at that speed. When it would speed up after the electric load reduced, it would really get hopping, at about 1050 RPM it was real bad. So I followed the advice on the forum and reduced it to 735 with a smaller generator pulley. Now it's fine and still pulls 9 Kw easy which is enough for me. (I have a 12 Kw head)
Scott E
Ashwamegh 25/2 & ST12
Lister SR2 10Kw 'Long Edurance' genset on a 10 gallon sump/skid,
Onan 6.5NH in an old Jeager Compressor trailer and a few CCK's

hotater

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Re: Lovson 20-2
« Reply #12 on: January 07, 2007, 07:22:01 PM »
ONLY because Scott, in what has to be one of the most informative post in a long time, mentioned the door filter---



Diamond in the rough is a good description, too.  And like a diamond, it can be cut in many different ways and all of the are usually 'right'....but if wrong can be changed easily.
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

okiezeke

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Re: Lovson 20-2
« Reply #13 on: January 07, 2007, 08:51:12 PM »
Hi,
Just back from the garage with another question(I did run a search to see what was already here on the forum)  Alll 4 of my valves show wear on one side of the stem and look bent when I chuck them in a drill and rotate them.  I'm thinking of taking the heads and valves to the local machine shop and tell them to "fix em",  but then I wonder if American made valves are available.  I feel I could probably re-lap them OK, but am reluctant to try to straighten.  Anybody found a source?  The valves are all the same, stems .434, width 1.563, and length a hair over 6 1/2" (my micrometer doesnt go that big)  thanks,
Zeke
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger

okiezeke

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Re: Lovson 20-2
« Reply #14 on: January 07, 2007, 09:02:05 PM »
Hotater,
Great picture of the filter.  I'm going to build one just like it!
Zeke
Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger