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Messages - mikenash

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Original Lister Cs Engines / Re: CS 3/6/8 - 1 rebuild
« on: September 21, 2016, 09:21:25 PM »
Hi Stef!

I think that would be superb what you have done gone and done... (Hows that for a convoluted a reply!)

As to oiling into the "oil here" hole, I wouldn't worry... Others can correct me if I am wrong, but I only use the "oil here orifice" when the engine has been standing a substantial length of time, for daily startup, u shouldn't need to worry... If its a "Show" engine, a quick dash of oil prior to running would be all that is required,along with the general slop over the rockers and links before you wind it up... Possibly install one of those "Lathe-Bed type Oil cups".... Makes life a bit easier and simpler in the long run...(As well as keeps the grit out too! More often than not, grit from a spanner ends up in a machine uninvited!)

Actually, come to think of it, I haven't used the "Oil Here" hole for many moons.... Even after standing.... I simply turn my beast over for an extended period on the 220v starter motor until it gets well and truly juiced up...... The friction starter spins it over at about 100RPM or so(Guestimated of course!)....


Hey Ed

What's the 220V friction starter?  I'd be interested to see an image if there is one?  Or some details?

Thanks, Mike

PS - the projects are still piling up...Life is fun!! Last quickie was a Timney on a 30-06...and change the cyl head on TM1, and replace the head gasket, and clean the radiator header tank, and sort a leak on the oil pump, and de-carbon the exhaust, and clean up the driveway after the de-carbon job, and.......Damn, no wonder I'm knackered!

Mike, gidday. Pretty much all parts that are cam actuated are mounted slightly offset so they turn during use, this cuts down on wear and grooving. You will notice the valve lifters do this, as does that pump lifter you mention. Here in NZ, they spin in the opposite direction to the northern hemisphere where almost all things run backwards....... thats why noone up there has noticed, its  the new normality for them    :)
An easy way to set injector timing is to temporarily mount the injector so it squirts on the flywheel rim as the engine is cranked. The oil deposit will show you exactly where in the cycle it opens. This too isnt so critical, but better slightly retarded, ie, at TDC or very slightly after.  This timing can be changed to better suit the fuel you are using, Ive found it can quieten the engine with some fuels. Eventually you will find the best compromise.. Unlike ignition timing with a petrol engine, the pump timing is "flat". Its not an explosion engine but a long burn throughout the expansion stroke, the static timing just sets when the burn  begins, the rack position sets how long it burns for.

G'day Dayle - interesting thoughts, mate, thanks.

Made myself a pointer and a mark on one flywheel rim for TDC exactly and now have all timings good, I think.  Need to buy a dial gauge and a stand, maybe

 Did the spill timing at 20 degrees BTDC; but noted several comments saying "later is better/safer" here and there - so we'll see.

Marked the valve openings and closings on the flywheel using the "when the pushrod gets loose/tight" method to decide actual opening/closing points then calculated their positions with the steel tape.  Three out of four were only one degree away from "nominal" which says something about a seventy-year-old machine . . .

Have had it firing but not running & it chuffs out smoke from the COV; so I took that out for a look & the gasket ring is shot.

Did the bump/squish measure (I forget what it came out at, might have been 60 thou? I have the figure at work not at home) a bit on the low-compression side even though it only has one base gasket in place.  So while thinking about that and about the COV gasket I bought a glow plug insert from England as my compression - according to the bump - is just the right compromise for that . . . so that will be something to play with as well

Have had the injector pump & injector stripped down to component parts so hope the rack is right as no marks on it - we'll see.  Kept getting slight blockages of the injector nozzle where it would spray a few times and then stop.  Cleaned it out many times with brakleen & compressed air and a piece of very thin copper wire & gthe magnifying glass as my old eyes can't see hole properly otherwise . . . a modern filter is on the shopping list.

I don't have a mental picture of how well/how far/how much that jet/mist from the injector should be, so we'll see if it's OK or not.  Both injector & pump are cheap to replace ex Rob in Australia anyway if I am suspicious of them

Just scavenged a couple of metres of heavy-wall 300 X 70 X 12 channel to make a base that should bring the crank up to a good working height - I'm sure I have some big long 20mm TruBolts somewhere . . .  need about three tonnes of concrete I think.

Tim will tell.  Thanks for your thoughts

Cheers, Mike

Everything else / Re: Blasphemy..... Solar power.
« on: August 16, 2016, 04:00:29 AM »
It occurs to me that some types of geothermal should be practical in some places. Perhaps those active zones are just not stable enough?


I have been to new Zealand a few times to do Photoshoots.  The geothermal in areas there is amazing. You could literally sink a steam well in your own back yard and some people have.
Around the most active area, rotoroua, Geo is huge for heating and spas.  I don't think there is a motel in the place that doesn't have a geo thermal spa in every room.  The water is so hot you generally have to add cold water to make it bearable.  Depends where you are and what your tolerance is but it isn't lacking in warmth, put it that way.

There is no tap to turn off the Geo water, don't know if they can't for physical reasons with pressure etc or they just don't bother. It just overflows 24/7 and no greenee seems to whine about water wasteage.

The rotoroua convention centre/ indoor stadium is totally geo powered. They have a turbine for power and of course the place is heated the same way.  It's on a very active lake where you can walk around and see small steam geysers coming out of the lake shore and around.  It's got a 18" fence around it but of course like all good tourists we couldn't read Kiwi english so walked around and had a good look. It was amazing.
We went to a thermal park and the gysers there were the ones that shot into the air on command and smaller ones coming out of no where. there was a lake that steamed even though the day was near 30C and was far too hot to put your hand in.

They have a few geo power generation plants around the area mainly around Taupo where the geo park we went to was. They are building more plants ATM but the Rotorua council has of course laws on tapping the go power even for homeowners.  They have regulations ( read taxes) on this basically inexhaustible supply of power.  The temps of the geo ranges from 40 which is warm to 140 which is well past saturated steam.
Being the type I am, I'd be looking into a mini Geo powered Turbine no worries.

One thing about the place we learned, it stinks.  We were looking in a tourist guide and in a sub headline on an ad from one place it had " No Sulphur Smell". We wondered what that was about till we were about 20 Km away ans started accusing one another of ripe gaseous emissions.  Of course when they hadn't subsided for 10 min, the penny dropped. You do get a bit used to it after a few hours but when you first get near the lake... Hooley dooley!

As an aside, the place really did my head in. having been self employed about 90% of my life and studied business, marketing and sales, I was surprised how quiet the place was. There was a strip of over 1KM down the main drag where it was only hotels one beside the other, both sides of the road.  each one only appeard to have a few cars there.  we went into town for dinner and the end;ess restaurants were the same.  miles of them, hundreds of seats and about 10% occupancy and that's being generous.
We found a Pub with a nice outdoor setting and when the girl brought us our food I started chatting her up saying that I supposed the busy season, Christmas was just around the corner. She looked a bit blankly and said , no not really. I said oh, when do all the crowds come?  She looked again and said we don't really get a rush at any time, it's pretty much constant.  I said Oh, ok, is this the quiet time then? No, it's always like this.

I'm thinking WTF?? I said, thinking she may not know the area, Have you been living here long? She said yes, I was born here and still live at home.  By now I'm thinking the nice girl must be on drugs or something.
You can't have 5000 hotel beds in a little tourist  town along with endless restaurants and have them survive at 10% saturation.
I asked some more people about the rush and got the same answers, it's the same here all the time, just like this..... W T F ???

Don't know how that works. It's just not little owner/ operator places, there is an international Chain hotel there with a 7 storey building and that probably didn't even have 20 cars in the carpark either.
I felt sorry for the locals so we stayed a couple of nights in the smaller places but although clean, they were woefully out of date.  No wonder the owners rolled out teh threadbare red carpet though and thanked us like we saved their lives.  the 3rd night it was the big hotel though for some real comfort and a bit of luxury. Didn't even take much talking to get a massive upgrade with them into a suite for a middle range room price.

I got to admit, my real "Idealistic" power is Hydro.  Solar is nice and practical and all that but not enough real fun involved as in no moving parts.  Hydro would be great to play with in my old age.
Of course i live on the driest freaking continent in teh world  so water  sufficent for hydro is limited here even if we do have the worlds largest hydro scheme at one point.
I have spent many hours looking for properties that I could do a hydro setup on and there are some around although always distant from any major town let alone city.  I could probably pick something up for $100K  But that is a lot of money to pay for a hobby!!  Not to say I wouldn't do it anyway.  I am not much of a traveler but I and the Mrs could be very happy in a remote bush location with a shack built from a few shipping containers and spend some quiet time away from the rat race.  I think we would still have to have a place in the rat race as well, too much quiet freaks me out so i'd have to acclimatise.   :0)

Lister in the shed, panels on the roof, water spinning up some various home made turbines and hydro generators.....  I could set up my own power company!  :0)

Hi there, Glort

Rotorua is an odd place - you can't extrapolate the Rotorua experience out to the rest of New Zealand

It had a big tourism development a bunch of years ago when overseas tourism to NZ was basically bus-load after bus-load of Japanese tourists . . .

That model doesn't exist any more but the infrastructure still does

And tourists want a lot more these days than some hot pools and a Cultural Experience or two - and so they should

I am oversimplifying here, of course, but that's the guts of it.

New Zealand is almost completely "renewable" electricity generation - lots of wind turbines and a big "battery bank" of hydro

Electric cars would be great here if the price came down - we pay around $0.20 - $0.25 per kw/h; but almost $NZ 2.00 a litre (sort of $US 10.00 a gallon-ish) for our gas

And we are ripped-off on our back-into-the-meter solar just like everywhere else in the world . . . .

I have an off-the-grid property in development at the moment & the budget looks something like:

(1) Old 1939 6/1 CS and 5kW ST-clone - about $NZ 2000-2500 once all up and running
(2) Solar panels, inverter, batteries - around the $NZ 4500-7000 depending on spec
(3) 6kVA Honda generator in use whenever I am there at the moment - I think it was $NZ 1600?

Call it $NZ 10,000 and it is workable at that level in combination with a house with solar hot-water in summer and wetback hot-water in winter, LPG (Propane) hob in the kitchen, and a bit of a hands-on approach to managing the technology

If the average NZ power bill is something like $NZ 200 a month - that's a lot of months to pay it all back . . . .

But what isn't mentioned is the cost of getting the power to a rural site like mine - often $NZ 10K - 40K up front

Got the old Lister in the workshop now with the head off - a work in progress

Very interesting Forum you guys run here.  Thanks

What ever the 'rest' say I had no trouble following the tutorial.

I had plenty of time and deliberately assembled the gear train a tooth out in either direction so I had an idea of how wrong wrong could be, still didn't take me an hour.

Mikenash, when you adjust the IP - having loosened the bolt - start low and work up so as not to jam the injector pump, otherwise, at the top of the adjustment it's possible to lock the whole thing up,. Well it was with my 'Indian' injection pump.

I found marking one flat of the bolt with Typex - white typing correction fluid - helped.

Cheers Stef   

Cheers Stef, good advice, I will do that

Hey I have a concern re the oil pump and would appreciate an opinion

It looks and reads like an idiot-proof simple device - plunger, balls/valves & a spring - and it has a formed tin tubular cover over the plunger that the manual pump actuator/primer thingie bears on . . .

On my unit that cover will tilt-and-jam sideways when th priming lever is used and there's a funny bit of flat steel between the top of the tin cover and the priming lever.  it looks like a piece of 5 X 20 flat cut about 25 long ( sort of inch by quarter flat ) with a dimple in one end to accept the end of the cam follower/plunger that actuates the pump

It's just jammed/balanced there and will fall out at the drop of a hat - the dimple in its top sort of retains it below the cam follower end

And inside the cam housing, where the IP and oil pump cam runs, there's a vertical actuator rod thingie that follows the cam and operate the oil pump.  It has a mushroom head with a couple of flats machined off two sides of the mushroom.  I can't see anything to stop that rotating; nothing to keep the muhroom head flats parallel to the plane of rotation of the cam lobe - or perpindicular to the cam shaft if you want to think of it that way

Looking at the other things done inside this engine, I wonder if any of that is "non standard"?

I'd appreciate any thoughts

And is there an easy way I am stupidly missing to cut-and-paste an image here - picture worth a thousand words etc?

I appreciate the wisdom

Thanks, Mike

One thing that I did not place in my video on cam timing is that seldom does the valve lift overlap ( or center of "rocking" as you say) happen exactly at TDC, but very close. In other words looking by eyeball is centered but if you were to use a couple indicators on the lifters to get that part exactly at the middle of the overlap and a degree wheel on the crank shaft you would find that the gear will not mesh :(   On a CS the split happens just a few degrees ( 2 as I remember? )  prior to TDC,

 Reason this is important is my tutorial was designed to be easy to follow and done via eyeball. However if half science is applied as some have tried  a person can get into trouble and I have received some questions and indeed some terse scolding from people who say the entire deal is no good becauser it just doesnt work out.  Sooo, let me ad this.

 If you eyeball the relationship of the lifters and the placing of the crankshaft (and you have not had too much to drink) the correct gear mesh is the one that places the names parts and pieces in the relationship stated. SPlit the lifters and crankshaft at TDC.  However under close scrutiny the exact center of overlap and crankshaft being at TDC cant happen. It actually happens just  a couple prior to TDC is proper and NEVER after TDC.  As I said in the video, a tooth off is a LOT off and you will be obviously out of time via the eyeball. 

Hi 38ac

I didn't notice you had a video, duh! 

But your instructions were good

It's much much better to play with something you understand the functions and relationships of rather than to just slavishly follow instructional steps and sweat over getting something you don't understand wrong . . .

I figure:

(a) once you have your head around the rotational and timing relationships then you can tinker with it until it's OK - it wasn't until I read Ed's helpful post that I realised how easy it was to poke around in the cam area & pop out the idler & re-time stuff. (Thanks for that, Ed)

and (b) worst comes to worst, I can just take off a main bearing bell, re-time everything by the marks, and move onto the next problem/challenge/opportunity

When I had the idler and its pin/shaft bolt/thingie on the bench for a clean, the gear eyeballed-up good but I could feel some burring at the edges where repeated contact has just spalled a wee bit of metal out from the sharp edges of the teeth.  Normal?

And I figure that bolt/shaft goes back in slot upwards to catch a bit of splash oil for the bushing?  Or is that another newbie assumption

Thanks again for your advice

Cheers, Mike

Hey Ed

Thanks again for that simple fix.

I had an hour this evening so simply took the front cover off, reached in and popped out the idler, rotated the cam until the followers were rocking and - with a bit of fiddling around the crankshaft - put the cam back in.

Just very quickly it looks as if the inlet cam follower starts to come up maybe 50 or 60mm BTDC around the flywheel - maybe 6 or 8 degrees?  Can't be far off right

Ran out of time to do anything more but it's a five-minute job to change if I have to move it a tooth

Of course with the pump cover off I can see a few more jobs - small flats developing on the roller that follows the governor, what looks like should be a roller on the cam-follower for the oil pump but doesn't seem to go round . . . and so it goes

It's so easy to lever out a gib key and slide a flywheel outwards that they are no barrier to working in those areas at all

Unsiezed the 15/16 head nut on the IP adjustor while I was there so once I have the cam timing right I will enjoy tinkering with the spill timing.  Got an old 24mm ring-and-open-ender here I can cut in half to do that adjustment if space is tight

Thanks again for the advice

Cheers, Mike

Hi MN,

Looks like your cam is indeed around 90 degrees out.... Don't stress, its easy to sort, don't even need to pull off a bearing trumpet... pop off the cylinder (its loose anyway) and pull off the piston, just to get it out the way. Put the crank to around 90 BTDC and loosen the top right bolt of the IP side trumpet... this would loosen the idler gear shaft. Take out the idler gear and check it over for missing teeth and damage while you are at it. If its serviceable, put it back in place and just ignore the timing marks, there is a way easier way to do things.

Now turn the crankshaft to TDC as viewed from above through the "top hole" .... as close as you can judge it. Slip the idler shaft out the idler gear and unmesh it... While looking in the CC door, turn the camshaft and judge the cam followers until they are level with one another, ie intake starting to close, exhaust starting to open.... Pop the idler back into place and your timing should be pretty much spot on. One tooth in either direction gives a BIG change to the position of the crankshaft when the cam followers are level with one another and "on the rock"....

Sometimes, you might have to try and jump the mesh one way or the other by a tooth or so to get things right.... Turn the motor over in the direction of "normal" rotation to confirm your setting, a bit of wear on the gears will give "false" estimates!!

Job Done!

Once this is done, do your IP timing too, it is well worth it!!

Keep it spinning....


PS - A bit of an afterthought....Check your exhaust rocker for damage/bending... If the idler and other gears' teeth are intact, it looks like the last person to PM the unit didn't know about valve timing.... A solid smack on the valve from the piston, might have buckled the rocker too....and...there is no way it could have run as it is now...

Hi Ed


Can't fault that for KISS

I'm just beginning to appreciate the simplicity & elegance of these things

First time I took the gibs & flywheels off it took me an hour of hammering and wedging.  Now with gibs & keyways tidied up and shafts polished and a bit of coppercote it's a two minute job.

I suspect much of the machine is like that

I was going to buy a Lister-clone but decided, eventually, an original one was a better bet, simply in terms of original build quality

I have an ST-clone 5kW unit coming from China for it (a good Stamford one, 20 years old, is still worth $2K here, sadly) and I'm hoping it'll just need maybe bearing/housing work to be a solid, serviceable unit

We'll see how it pans out

Plus I have the wonderfully helpful OldTimer Engines man, Rob, in our big Offshore Island, who seems to have all the parts I'll ever need

Interesting times ahead

Thanks for your input & everyone else'

Cheers, Mike

A large degree wheel can also be helpful, although not strictly necessary. I do like the practical approach that 38ac covers in his write-ups. Look at the WOK section.


Okey-dokey.  Thanks, Dieselgman, folks, for all your advice(s), this is what I did

(and excuse me again while I am long-winded, sorry)

Step one - used the vernier-down-the-injector hole to find TDC - rotating the engine in both directions.  The two marks are about 6mm (one degree) apart so that will do.

Step two – my good steel tape says the flywheel is 1906mm in circumference; and George’s Utterpower spec page says the 23.5 inch wheel is 1887mm in circumference.  So that will do.

(1906 divided by 360 = 5.2944mm per degree)

Step three – using your recommended technique (valve opening begins when the pushrod tightens up and valve closing ends when it comes loose again) I marked my actual Intake Open, Intake Closed, Exhaust Open and Exhaust closed on the flywheel with a big black felt pen

(Newbie/idiot comment: Rotation is clockwise if I am facing the flywheel on the injector/oil pump side, and thus, say, the mark for the nominal opening point of the intake valve at 4-8 degrees BTDC is 4-8 degrees CLOCKWISE - ahead -  around the flywheel?)

Your specs say:
Intake Opens 4-8 degrees BTDC say 6 degrees nominal
Intake Closes 14-18 degrees ABDC say 16 degrees
Exhaust opens 42-48 degrees BBDC say 45 degrees
Exhaust closes 6-10 degrees ATDC say 8 degrees

Now, I don’t have a degree wheel but I can measure, calculate and count.  So, if TDC is 0/360 degrees, then:

I.O. nom. 354 degrees?
I.C. nom. 196 degrees?
E.O. nom. 135 degrees?
E.C. nom. 8 degrees?

These are good nominal points if my calculation is OK

Measuring my markings around the flywheel (actuals garnered by the “when the pushrod tightens up/comes loose” method - so not TOO bad probably – gives me these figures below
(not corrected in any way):

I.O. at 105 degrees – 111 degrees ahead of nom at 354
I.C at 308 degrees – 112 degrees ahead of nom at 196
E.O at 273 degrees – 138 degrees ahead of nom at 135
E.C at 95 degrees – 87 degrees ahead of nom at 8

I had previously set the valve clearances at TDC as per advice at 0.017 (my 0.45mm feeler gauge) and 0.032 (my 0.8mm feeler gauge)

They seem like very big gaps but I take on board the wonderful 38ac lecture on valves/lash/timing/breathing . . .

(Just a thought that if my ACTUAL exhaust valve duration is from 273 degrees to 95 degrees – fully open around 6 degrees perhaps, depending on cam profile – no wonder the valve hits the expletive-deleted piston?)

(I haven’t figured a way to copy/paste images onto here, otherwise I would post one showing the line on one tooth of the cam gear nestled between the dots of two teeth of the idler gear)

Looking at the above makes me wonder if my cam train’s timing is maybe 90 degrees out of whack or something similar?

I guess next I’ll pull a main bearing housing off and check the drive gear-to-idler gear marks?

Do I have my thinking right or are there some Newbie Dumb Assumptions being made here?

FWIW I am a 59-year-old engineer who grew up with old pushrod/points/carbs Bedford trucks, and spent a chunk of life repairing sawmill machinery; so while the Lister Diesel is unfamiliar to me, many of the concepts are not . . .

I’m interested/amused that this engine was sold to me as “used to run OK, won’t take much to get it going . . . .”

Once again I appreciate the interest and advice

Here is the valve timing diagram... this may help you check your valve clearance issue. I would try doing the valve adjustment at tdc on compression stroke.


Hi Dieselgman

Did I say "thanks" for this?  I may have forgotten to do so

Wonderful.  It's just what I needed and what i spent a half-hour this morning googling for unsucessfully

I will mark TDC with care, do that 24 qnd 3/4 inch (actually will measure in MM) diameter to circumference to degrees thing and draw some pictures on the flywheel

Cheers, Mike


Couldn't be something simple like someone has put the wrong Pushrod in Could it?

Hi there, Glort

I wondered the same thing myself, since it had "allegedly" "been running" with it bent

I have ordered two new pushrods to eliminate that possibility

In the meantime - armed with all the wonderful information from your colleagues - I will measure and think

Thanks, Mike

Hi there Mikenash,
                          Am sure there are experts here who can pinpoint your problem, but if you are sure the timing gears are correctly meshed, then time to look elsewhere. The hollow cams are fixed to the camshaft with taper pins. Is it possible that a pin is broken or wrongly fitted ? Time to check valve train timing. First properly locate TDC. Rig a pointer near flywheel timing marks. Pull injector and poke a rod down on the piston.  Rotate crank till rod is say 20mm down on piston before TDC, mark flywheel at the pointer. Then mark again when say 20 mm down after TDC, Measure half way between flywheel marks and this is accurate TDC. Now rotate and watch valves at the junction of intake and exhaust strokes (not compression stroke). Exhaust valve should be just closing and intake about to open right at TDC. If this is not happening then you still have a valve timing problem somewhere. Hope this helps. Regards,

Hi there, combustor

Thanks for your thoughts - a good insight

I had thought, since the exhaust valve seemed to be affected but not the intake, and since the engine arrived with a bent exhaust pushrod,  that there might be a problem with that exhaust valve train specifically . . . .

But on further thought if the intake valve begins to open as the piston descends on the intake stroke (as seems sensible?), whereas the exhaust valve is open during the exhaust stroke and maybe begins to close as the piston approaches the top of that stroke, it may be that - relatively speaking - the exhaust valve has more open duration around the top of a stroke that the intake does, so that, if there is a general clearance problem, the intake valve may not be affected whereas the exhaust one might be?

I'll have to think and measure further

I will get out the vernier caliper or some such and stick that down the hole for a start-off

Thanks.  I appreciate all the advice

Cheers, Mike

When you put the barrel back on and put the straight edge on it, I assume you mean that the gap was between the straight edge and the top of the piston?  Did you have anything clamping the barrel down?  It could be that you are compressing the gaskets at the bottom of the barrel more than you realize when torquing the head bolts and the bump clearance isn't what you expect.  I'd get the lead/solder/plastigage and check the bump clearance before messing with valve clearance and timing.

Hi Thob

Thanks to you and all the other very helpful chaps here - I hadn't expected such a flow of advice and I really appreciate it all

Yes, just a skerrick of daylight between the straight edge and top of the piston.

And, yes, re flattening the gasket, I had thought of that - it seemed to me that the base gasket at about 0.5mm? wouldn't compress enough to use up all the headspace donated by the head gasket at about 2mm ?  Bu that's pretty rough thinking

Yep, plastigauge is next'

Thanks, appreciate the help

Cheers, Mike

Maybe the cylinder block has been machined too many times eg it is too low

Thanks for your thoughts, Gippslander

Yep, you may be right.  History is unknown

I had thought, since the exhaust valve seemed to be affected but not the intake, and since the engine arrived with a bent exhaust pushrod,  that there might be a problem with that exhaust valve train specifically . . . .

But on further thought if the intake valve begins to open as the piston descends on the intake stroke (as seems sensible?), whereas the exhaust valve is open during the exhaust stroke and maybe begins to close as the piston approaches the top of that stroke, it may be that - relatively speaking - the exhaust valve has more open duration around the top of a stroke that the intake does, so that, if there is a general clearance problem, the intake valve may not be affected whereas the exhaust one might be?

I'll have to think and measure further

Thanks again for your thoughts. 

Cheers, Mike

Hi guys.

I have been browsing here for a while while playing with an old CS and appreciating all the wealth of wisdom and experience.

Perhaps someone can help me with a dilemma - excuse me if I seem long-winded; it seemed a detailed description was in order.

I can't understand how to post images here?

Down here at the bottom of the world in New Zealand I have a 1943 CS - the ID plate says # CS43345 and 5.6 HP and Spec 5/1/35 and RPM 650.650

Its provenance is unknown except that I got it partially seized and with a bent exhaust pushrod.  The previous owner stated it was "either hydrauliced or something like that and the pushrod will bend as a safety valve" - in his opinion

I have had the head, piston, conrod, barrel etc off and stripped.  Big-end shells, pin-to-bush etc seem really good

For some reason (possibly related to the problem below) it had two head gaskets fitted - both shot

I have cleaned all the sludge out of the crankcase and inspected the crank and cam and they looked OK.

Yesterday I stripped the head and cleaned out all the old carbon and looked at the seats (90%) and guides (70% but serviceable) and cleaned out all the old sludge around the springs etc

Today - after cleaning everything thoroughly - I refitted barrel, piston, head etc

Before fitting the head I put a straight-edge across the top of the barrel with the piston at TDC and there's a just-visible smidgen of a gap.  It seemed to me I was justified in fitting the head on the assumption that the thickness of the ring of the head-gasket would provide an approximation of a working clearance piston-to-head - figured I'd get some lead or plasti-gauge tomorrow, Monday, and have a proper measure

I torqued the head down, fitted pushrods and rockers, rotated the engine so the intake valve was fully open, set the exhaust valve clearance to around 17 thou, rotated the engine further, and found the exhaust valve was hitting the piston.

I increased the valve clearance incrementally until, at a ridiculous 2.5mm (approx 1/10th of an inch) the engine would rotate without contact.  I guess the exhaust-open duration is about half what it should be?

Things I checked:

Short pushrod on exhaust, longer on intake

Cam followers, pushrod ends, "tappet" adjusters etc all clean

Cam timing seems OK (line on cam gear tooth is between dots on two teeth of idler gear)

Took the head back of and looked at valves etc and re-assembled.

Same result?

What am I missing?  It seems to me something in the exhaust valve-train is about 1/8 inch longer than it should be?

Maybe I have made some dumb newbie mistake?

I'd appreciate any thoughts

Thanks, Mike

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