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
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
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
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:
18 years ago