Lister CS puzzle

Had a guy contact me today with a very long and detailed email regarding the cam
followers/tappets on a Lister CS diesel. The enquiry also ran over into the
clones made in India as well.
Seemingly, the exhaust tappet rotates but the inlet doesn't, and the guy was
wondering why.
Now, the Lister cold-starting diesels have been around for a few years, and
there are quite a lot still running, both working and in preservation, so I was
a bit intrigued to see what possible causes I could find.
First of all, the followers that I have both spares and from working engines all
show equal wear underneath, so there must have been a degeree of rotation. The
cam is offset to the follower base as is pretty standard practice, so no
surprises there.
The two followers are different in that the exhaust has a screwed-in cup to take
the pushrod and this forms a collar that the valve lifter hooks underneath. The
corresponding pushrod is therefore shorter. The exhaust valve clearances are not
exactly precise, with nearly 20" of tubular steel pushrod in the circuit, and
the rocker gear is grease lubricated.
The camshaft does have different cams according to the parts book, and I have a
new complete camshaft in the workshop which I will look at later to see if tere
is anything visual between the two.
Lubrication is by splash from a trough in the crankcase, but the exhaust side
bearing is a bit remote, and may usually be expected to run looser than the gear
end bearing.
I can't think of any reason why this guy's particular example doesn't do it, but
would appreciate any other thoughts on the subject.
Peter & Rita Forbes
Engine pages for preservation info:
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Reply to
Peter A Forbes
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Chances are that it picked up in the bush the push rod passes through and this is allowing up and down but not around or maybe the same at the other end.
Martin P
underneath. The
Reply to
Did it run over the quality of build and likely longevity of these clones?
Reply to
Andrew Heggie
Yes, the problems of the curry clones is pretty well documented now, and a picture of an off-line cam follower face was sent to me by the enquirer (George Breckenridge after a bit of discussion about the details of the cams.
It seems that the opening period and the lift of the exhaust is much greater than the inlet, and George reckons that would be sufficient to always make the exhaust follower move while the inlet may not, depending on lubrication etc etc.
I'm keeping an open mind on the matter, the Lister ones appear both to rotate, I haven't got any Indian built engines to worry about! :-))

Reply to
Peter A Forbes
Andrew, The quality is as poor as one would think. If buying one as I just did you would have to look at it as a kit. I'm lucky being a machinist and having the tool to make bushings, shims and everything else I will need to get good use from this engine. The castings are good but the machine work and assembly is very poor. Loose threads and gears. One rocker almost off the valve, warped pushrods, bad bearing on the connecting rod. And the paint is a metalic green I have not seen in 30 years and never want to see again. And they paint everything once it is on the shipping pallet. You get what you pay for with these engines. Caroll F Via
Reply to
Caroll Via
Thanks for that feedback, from later postings it looks like a second hand one may be a better place to look.
I see the comments about tappet wear and it makes me wonder what factors do contribute to longevity? Having had over 20k hours from an aircooled Lister genset, which would have gone on if it hadn't rattled the control box to pieces, I wonder how long an engine will run between major rebuilds.
Reply to
Andrew Heggie
That's why our Iron Toys weigh so much. It helps to damp the vibration and a well supported main bearing is a long lived main bearing.
Massive crank journals stay cooler and can survive with poorer more sketchy lubrication.
Big gears in graphite-laden cast iron wear well, especially if no-one lubricates them with oil in their first few hours/days!
Makes them more difficult to carry about and I wonder how well modern high speed genny last.
Kim Siddorn, Regia Anglorum
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Reply to
J K Siddorn

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