Lister Engines > Original Lister Cs Engines

Rebuilding a 1951 Lister CS 6hp

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Mr Lister:

This week I have been rebuilding an engine I bought last February which had a leaky exhaust valve and some fuel injection problems.

Here is a brief account of how I got it running again.

This weekend I have rebuilt the valve gear on a 1951 Lister CS 6/1 by
fitting new valve guides, valve springs and lapping in the two new valves
with grinding paste.

I was a little concerned about the exhaust valve still leaking a bit of
compression, but this has now settled down and a reasonable amount of
compression has been restored.

I had the same problem with my injector pump as Andy was experiencing.  It
was pumping fuel to the injector, but without sufficient pressure to fire
the injector.

After consulting fellow enthusiasts on the stationary engine list, I was
advised to undo the fuel delivery pipe on the top of the injector pump and
check that the delivery valve was working correctly.

On unscrewing the top "nut" from the injector pump and watching out so as
not to lose the spring, I saw the top of the delivery valve which looks a
bit like a bowler hat.   It is located in the centre of a cylindrical
chamber into which the nut screws.  This chamber is normally full of high
pressure fuel and the delivery valve opens with the rising fuelpressure as
th pump plunger rises, and then snaps shut unter the action of the spring.

The delivery valve has to be free to move up and down by about 1/8" inorder
to work correctly.  Mine was stuck in the up position, allowing fuel to
leave the pump when the plunger was pushed in, but also flow back when the
plunger retracted.

The solution to my problem was to free the delivery valve by tapping it
downwards VERY GENTLY with a mandrel made from a short length of small bore
tube. (Microbore copper would probaby do).  The valve had seized in the open
postition and neededa couple of gentle taps to get it to loosen off.  This
could be assisted by soaking the valve and the delivery chamber overnight in

Once free, the valve pops up with the plunger pressure and sinks downwards
as the plunger retracts.

To test the injector, I removed it from the cylinder head and laid it on top
of the head and facing away from me.

(VERY IMPORTANT - this injector will shoot toxic diesel fuel about 4 feet
distance at 110 atmospheres of pressure - it would instantly blind you if
you got it in the eye, and will even inject fuel into your skin if you get
in the way. It will continue to shoot fuel at this pressure even if the
flywheel is turning very clowly or just over the injection point - TAKE

I reconnected the high pressure fuel deliver pipe and turned the engine
over several times. After about 40 revolutions,  the injector fired a good
spray of fuel, and closed with a satisfying creak sound.

Now that I had fixed my fuel problem, I was keen to crank the engine over an
get it to run.

It had no air cleaner, no exhaust pipe or muffler, and the diesel was
temporarily rigged up in a 1 litre bottle sitting on topof the fuel filter
and wired to the cylinder head.

After a few starting attemptsit gave a couple of grey smokey puffs from the
exhaust port.

We then got a small propane torch and held the flame about 6" from the inlet
port. This was enough to preheat the combustion air, but not so close that
the engine only sucked in burnt propane fumes (CO2 and H20).   After about 3
minutes of gentle warming and turning the engine over - decompressed,  with
the starting handle we got it to start.  The first real power stroke blew
out a lot of soot into my helper's face, and I man-handled the fuel pump
rack to maintain a reasonable constant rpm, because this engine was lacking
the governor spring.

I noted that it was quite responsive to the position of the rack, and
pulling out the rack a little was accompanied by a few very loud power
strokes and sparks of burning carbon shooting out of the open exhaust port!

After about 5 minutes of playing the throttle, I shut the engine off,
because I had been running it without coolant, and the old oil in the sump
was less than adequate for continued running.

Chuffed to bits!


Thanks Ken for the very informative posting.  I was getting rather annoyed at all the strutting and puffing on this forum.  It's nice to see someone posting information germain to the subject and stating the steps clearly and concisely to troubleshoot a lister (or oid, as the case may be).  For those of us who are intending to be owners in the near future, this kind of post is a godsend.
Stan's also nice to be able to attach a name to the poster, rather than some enigmatic non de plume.

Mr Lister:

Thanks for your post.

I agree that what this list needs is plenty more sound practical advice on how to work with these engines regardless of their age and manufacturer.

Yesterday I gave up on the injection pump because I had heard a rumour that if you start to mess with them they end up a can of worms.

I sought advice from someone who regularly maintains them, he said that I could proceed with confidence into the elivery valve chamber without risk of damage to the plunger and any of the more precision areas of the pump. This is the sort of knowledge that needs to be shared amongst the group.

I grew up in the 70's and messed around with model glow engines, but had never worked on full size diesels before. 

There is nothing hard or complicated about the Lister, you just need a few correct tools and the confidence to proceed with the repair.

I think that anyone who wants to run a Listeroid should have a go at a strip-down and rebuild to see how straight forward it is.

I now have another working engine, from one that was bought last year in a non-running condition and I have had a satisfying, but oily weekend!


Ken, A very good to know post on stuck injector delivery valve, and a most enjoyable read about your resurrection of a 55 (!) year old Lister.  Thanks! Bruce

Mr Lister:
BruceM & list,

The 1951 Lister is now back on it's trailer.

There are a few of photos of it on my Lister News site:

The new valve gear works fine and it started first swing.   Not bad for something that has not run for 20 years or so.



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