Lister CD 8hp

[cobbadog]

Hi Guys,
I have had this great little engine for a few years now and it is time to get it up on a transporter to make it easy to move around and take to rallies. I have almost finished the transporter and its nearly time to mount the engine onto it. My engine originally was a generator set off a farm about 100 kilometres away but now has no generator. Going by the serial number it was built about 1947 and has a letter M in it which may mean it was a marine engine. This also has a radiator for cooling as I was told it is a 'high speed' model (1200 rpm) and also originally had an external oil tank and ran as a dry sump arrangement. I now need an external oil tank to complete the set up and need to know details on this tank like size and quantity of oil to be held. Hopefully someone out there can help with the sizes or a tank here in NSW Australia.
I have had the engine running by putting some oil in the sump and clamping a flexible hose from the high pressure outlet to the return line. This does work for a short time but then the pressure gets too high for 3 utilux clips to hold the hose in place and then everything within reach gets a dose of 'rust proofing' diesel oil.
Thanks in advance for any further information.
Cobba

[richardhula]

The CDM was the marine version and would explain why it has dry sump system.

I think the scavenge pump flow rate is beween three and five times that of the pressure pump to avoid build up of oil in sump. Looping scavenge outlet to pressure pump inlet (assuming that's what you did), I'm not surprised you have had the issues therefore.

Is there not an external PRV in the circuit similar to this JP one?




Regarding oil tank check out my post here

As mentioned the tank is designed to contain approx 25 litres of oil, with a horizontal tray dividing the tank three quarters of height up from the base. In this tray are locations for two large fine mesh filter screens secured by circlips, and the scavenge outlet via PRV feeds into top of tank. Inspection covers can be seen on top to allow access to each filter screen for cleaning. There is also an overflow pipe located in tray with neck some distance above its base to ensure oil can pass to bottom of tank and hence to pressure pump inlet, if filters become blocked. The tank vent fitting is suitable point to attach a crankcase breather pipe if there is such a point on the engine.

Just found this image which better illustrates tank design and how its plumbed into engine.

[cobbadog]

Hi Richard,
Thank you so very much for that diagram. It resolves the problem of what pipe goes where. My pressure valve setup is similar to the one you posted and yes you are right the pressure is through the roof and is why I could not retain it in the loop, just too much pressure for 3 quality hose clamps on straight copper pipe. Now I can look at getting the tank bent up and I can start on it soon enough.
Thank you once again it is a great big help to me.
John

[cobbadog]

Hi again,
I have been thinking about this set up and for me to be certain that I understand the way in which it is to work,

I should mount the bottom of the tank at a height level to the top of the oil pumps.

When the engine is stopped, does the oil equalise out and sit in the sump of the engine and oil tank as well?

I am planning on using a smaller tank as this is just for Rallies and is not running long term or under a lot of load. I was considering about 4 - 5 litres of oil for my situation.
It also appears that I will have to strip and clean the Pressure Relief Valve assembly to make sure it is working correctly.
Any thought and advise is gratefully appreciated. Chances of finding an original tank out here are next to none so will be making the tank.
Cheers John

[richardhula]

Lister's recommended that the base of the oil tank was level with the pressure pump. I know of several installations mainly with JP's where the tank is higher though including my own which is maybe 12 inches above oil pump, as shown below. You will see the copper one illustrated in my link to tanks above is located even higher, above the flywheel. This of course allows the tank to be drained easily and doesn't seem to cause any issues when engine is running



If you refer to the PRV drawing, you will see there is a check valve that prevents oil draining back via pressure pump into sump when engine is stopped. As you are heavily reliant on this with a higher mounted tank and not trusting it completely, I have a ball valve in oil feed to pump which I close when laying the boat up for a week or more, with suitable sticky note reminder by engine start button  

Note that when engine is started the light check valve spring is easily compressed by oil pressure to allow oil flow, and the more powerful pressure control spring comes into play. The design can be seen to maintain oil pressure relative to scavenge pump pressure.

If you are just going to rally your engine you might be interested to see this trailer mounted demo Lister 9/1 (JP1) installation which does seem to have a smaller than normal oil tank.



Suggest you make the tank large enough to ensure that scavenge flow back to tank is established before tank is drained by feed to pressure pump.

[cobbadog]

Once again thank you Richard for all your advise and especially detailed photos. There is a lot more involved in this exercise than I first thought. With specific quantity of oil required and the need for an external tank I am beginning to think that I should take the gears out of the scavenge pump and run the engine as a normal wet sump.
I had a look at the images you just posted and they are helpful but the smaller pic when opened takes me to you photobucket and I could not find any pics of the 'trailer mounted demo Lister 9/1 (JPI). However I do like the pics of the beautiful narrow boats.
Sorry for being such a nuisance but I need to ask questions to try and learn more.
Cheers john

[richardhula]

The trailer actually carries the engine room part of a traditiional narrowboat as publicity for the Rivetted Narrowboat company as shown below. Since they are affiliated to Marine Power Services who restore vintage diesels, it was this company that fitted the single cylinder Lister within as joint publicity.



Converting to wet sump is certainly possible, but consideration needs to be given to the oil pressure release valve which was integral on the wet sump industrial versions. If you decide to stick with the dry sump system a spin-on oil filter can be fitted in the scavenge return line to tank. This will actually be an improvement on the original as well as simplifying tank design which will need to be vented though. The quantity of oil in the tank is not critical as long as a head of oil is always available at the pressure pump inlet.

[cobbadog]

Thank you again Richard,
The trailer looks so good that I thought I was looking inside a narrow boat engine room. I will follow up on the inline oil filter and tank and ensure a good return line to the pump. Engine will hopefully be mounted onto the new transporter this weekend and I am looking for the 'rustic look' on this project.