Author Topic: Lister CD8 Diesel  (Read 1388 times)

cobbadog

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Lister CD8 Diesel
« on: December 22, 2022, 05:16:08 AM »
I have this CD8 diesel engine and when it came to me it was from a farm and use to drive a generator for the old farm house. When it came home to live with me the generator was long gone. Now I understand that this is a 'tropical' model when they run a radiator (I have the original honey comb radiator but it leaks like a sieve) but when it arrived here it had no oil tank and there was a rubber hose looped around to complete the flow of oil. This idea worked a treat until the engine built up too much oil pressure in the hose and would blow it off but the engine ran beautifully.
Since then I built my own oil tank and plumbed it in also fitting a free flow oil filter in line. I also added a good fuel filter to keep the fuel lines nice and clean.
I had put the engine under cover for about a year and now I am having issues with oil. What happens is I start the engine and run it at about idle and at that speed I hooked up a pressure gauge where the original gauge is and it reads 28psi more than needed going by some paper work I have. After about 4-5 minutes of running at idle it locks up as if there is no oil or pressure. I have to use a plumbers wrench to wind the engine backwards to unlock it. This scares me as I don't want to stuff a good engine and I need some help in resolving this problem please.
First shows the engine on my home made transporter.
Second shows the in line oil filter
Last shows the engine ID tag
« Last Edit: December 22, 2022, 05:22:25 AM by cobbadog »
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cobbadog

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Re: Lister CD8 Diesel
« Reply #1 on: December 22, 2022, 05:27:15 AM »
I will post all the information I have on how the oil is suppose to circulate but I am unsure of some of the pipes and would like any and all corrections pointed out and to identify "B and J" as I do not know what they are suppose to do. Once I have all the correct information I can go out and uncover the engine and start following all the lines and check things over again to make it run again as it should. Sorry I do not have any current pictures but should have some from tomorrow. I will post 3 pages of what I have and the first one I have labelled what I believe to be correct. If there is any other information available I would appreciate it as well.
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broncodriver99

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Re: Lister CD8 Diesel
« Reply #2 on: December 22, 2022, 01:43:22 PM »
Looking forward to the pics. It looks like your suspicions are right to me. Pipe J looks like the oil supply to the pressure pump from the tank and Pipe B looks like the pressure supply line from the pressure pump to the pressure regulating valve.

Where are you taking the pressure reading? I wonder if something is going on with the bypass valve causing the engine to starve for oil as well as not properly relieving to the tank. Seems like maybe the problem has been there since the rubber hose days.

cobbadog

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Re: Lister CD8 Diesel
« Reply #3 on: December 23, 2022, 05:06:30 AM »
Here we go.
After taking off the covers in over 2 years I started checking everything that I had done in order to fit my home made oil tank, in line filters for both oil and fuel. I had foolishly left the oil tap open and all oil from the tank had gone to the sump. So with decompression lever holding the valve open and the oil tap now closed, I cranked and cranked until all oil stopped returning to the tank. It looked a bit low so I added about another litre of oil to it. Now I can only guess the quantity of oil going by the size of the tank and guess that at the level of the oil now it has around 5 litres, just over an Imperial gallon. Next was to make sure that the fuel bowl and filter were good as it looked as if there was a bit of contamination in both. Cleaned the bowl at the tap and then took the bottom off the filter to clean that clear plastic bowl. Not a lot had to be cleaned out but it got done so I could eliminate these things. Rocker cover off and oiled the rockers as they explain in the book and fitted that back in place. I roughly bled the fuel line to the bleed nipple at the filter housing and got fuel out of that. I checked that the rack was free to move fully from STOP to open and this was a tiny bit sticky so I sprayed some Lanox on the shaft and it came good. I set the fast idle metal lug that holds the rack partially open and usually in that position it starts and runs fine. Happy with what I had done I decided to start it up. 2 swings on the crank and drop the decompression lever and it was away ticking over just above idle and sounding so good to hear it live again. After a few minutes it was sounding odd and it was then I noticed that I did not turn the fuel back on and was starving for fuel.
Yes that is over 2 years worth of Mango tree leaves under the home made trolley.
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cobbadog

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Re: Lister CD8 Diesel
« Reply #4 on: December 23, 2022, 05:20:07 AM »
Next are some closer pics of the oil tank I made and how the inline oil filter was fitted and of the twin oil pumps, one constant pressure to the engine and the other is the scavenger pump to run a dry sump.
Sorry you asked where I measured the oil pressure. That was done from the line that goes to the original gauge for oil pressure and engine temp.
With further investigation and help from broncodriver I have now confirmed that;
K is the scavenger pump return line to the regulating valve.
B is the Pressure supply to the regulating valve.
J is supply to the pressure pump.
It appears that all the plumbing is correct and going to all the right places.

Now after having to fully bleed the whole system again. The first 2 stages are easy with just using gravity to get to the bleed screw on the fuel filter. After that I removed the line at the pump and again cranked and cranked until I got a nice constant amount of fuel pushing gently up from the top. Next disconnect it at the injector, or where the fuel line goes into the rocker cover. After a heap cranking again I got the same amount of fuel dribbling out of the line so I connected it up. Did another start up this time confirming both oil and fuel taps were on and away it went again. Still running for a while until again a different sound happened and the engine was shutting down as if it was out of fuel again. To morrow is another day and will have another look at the fuel supply system but maybe I need to really get inside the fuel filter housing and check all is well inside.
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cobbadog

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Re: Lister CD8 Diesel
« Reply #5 on: December 23, 2022, 05:27:55 AM »
Here is a link to Ray running all be it rough. You can hear the rev range alter slightly at times and sometimes the transporter get a bit of a bounce up then goes away.

https://youtu.be/UjEJp8P6FT4
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cobbadog

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Re: Lister CD8 Diesel
« Reply #6 on: December 24, 2022, 12:24:06 AM »
Here is the latest. It appears that I now have all the air out of the fuel system so that is a good thing. I wanted to double check the oil pressure where the original non working gauge sits as this is the end of the oil line after running through the crank shaft. I know this gauge is as old as I am but it works and shows 26 psi which is more than the manual asks for of 15 - 20 psi.

So I started Ray up again and he was happily ticking over with the rack held open using that little metal lug which would roughly be about 1/4 throttle. HE ran for quite some time but then it started to lock up as it did before and I still had oil pressure. In order to free it up I use a set of stillsons to wind it backwards to allow it to let go. I felt the head and I could leave my bare hand on it and the top of the radiator was only just warm. I feel I have plenty of coolant in the system because I opened the drain cock at the bottom of the block and the level went down in the radiator.

Is there a bleed screw for trapped air in the head that I dont know about?

So I let it sit there for about 10 minutes and started him up again and as usual he always fires up easily. This time the lock happened a bit earlier so I am thinking that maybe it has something to do with temperature of the engine, but what?

Could there be a cracked ring that would or could cause this?
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broncodriver99

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Re: Lister CD8 Diesel
« Reply #7 on: December 24, 2022, 04:57:49 AM »
Is there any way to check the oil level in the engine? Any oil slobbering out of the exhaust? Can you see oil returning to the tank through the inspection door?

Definitely something odd going on towards the end of your video. Sounds like either a loss of fuel or compression. The hopping may just be a resonnant vibration.

Could also be hydralocking either from a buildup of sump oil or fuel/oil in a cylinder. If you have excess oil pressure there is no telling what that may cause. If lister specified a certain oil pressure they likely had a good reason. I would be tempted to pull the inspection cover on the engine and have a peek around for anything obvious. You should be able to get a peek at the bottom of the cylinder bores while in there. I would also at least temporarilly install a know good/accurate oil pressure gauge and adjust the bypass valve as needed to get oil pressure within range.

Looking at the design of the bypass valve it looks like it is possible for the scavenge pump to build enough pressure on the back side of the pressure pump bypass spool to prevent it from bypassing if the outlet/return to the tank is not free flowing and unrestricted. I don't know that that could cause any issues but just for the sake of being thorough. Also, if the oil filter housing is not plumbed in the correct direction you could be working against an anti-drainback valve in the cartridge. Again not sure if that would cause a problem but I would check it.
« Last Edit: December 24, 2022, 05:05:20 AM by broncodriver99 »

cobbadog

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Re: Lister CD8 Diesel
« Reply #8 on: December 24, 2022, 10:16:59 AM »
Cheers broncodriver.
With a dry sump there is no dipstick but by opening the top of the oil tank you can clearly see the oil returning at full speed. The diamter of the pipes used for the plumbing I did was exactly the same diamter as all the original pipes so no restriction there.
That bouncing and change in sound is curious but feel that the revs had changed slightly and causes resonnance bounce. Well thats my trian of thought at the moment.
I can easily adjust the oil pressure back at the pressure valve block and that very old gauge has been hooked up with a new gauge at the same time on the old David Brown tractor and read the same. So in time I will drop it back to being with in spec.
The oil filter has been connected in the correct orientation and so we can forget that one.

Later this afternoon after much thought and thinking of the possibilties I will lift thead off and piston out so I can get a good look at the bore and condition of the rings and bottom end main bearing. I believe it is either bearing or ring locking up. Have priced the parts already so will start on Boxing Day and go exploring.

Thank you for your thoughts and help in this matter I appreciate it very much. Have a wonderful Chrisatmas and stay warm over there while we sweat it out here.
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broncodriver99

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Re: Lister CD8 Diesel
« Reply #9 on: December 24, 2022, 03:49:37 PM »
Thank you for your thoughts and help in this matter I appreciate it very much. Have a wonderful Christmas and stay warm over there while we sweat it out here.

You are quite welcome and I hope you have a Merry Christmas as well.

It is quite chilly here this morning. 14 F(-10 C) with wind chills around 0 F(-18 C) and quite windy. It got down to 6 F(-14 C) last night I would definitely trade you for a little of that warmth today. Of course this is Tshirt weather to my Canadian neighbors to the north. Most of North America is going to experience the coldest Christmas in decades this year. I hope you guys aren't getting the opposite.

ajaffa1

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Re: Lister CD8 Diesel
« Reply #10 on: December 24, 2022, 08:21:15 PM »
Hi Guys, merry Christmas to you all. For what it`s worth, Bicheno Tasmania is expecting a balmy 26 centigrade today, I expect it will be around 40 where Cobbadog lives.
Has this problematic engine had any major work done before it came to you? I`m thinking the piston ring gap is too tight causing them to bind as the engine warms up.

How is the piston lubricated? I am guessing there is an oil thrower/dipper on the bottom of the big end bearing cap. Check that it is still there.

Bob

cobbadog

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Re: Lister CD8 Diesel
« Reply #11 on: December 24, 2022, 10:48:45 PM »
Too bloody cold for me over there so stay warm.
Well we are blessed today will only be around 28'c which is good for Summer temps, any hotter I'm looking for shade or somewhere cooler. Get less tolerant to stuff as I age disgracefully.

Oddly enough I have had this engine running for longer periods of time in the past and this issue has started after it has sat around for a couple of years.
Now I have no known history of the engine prior to it comming to live here only that it was coupled to a generator on a farm about an hour South of me at Buladelah. Ring gap is sounding the most likely culprit so will know more once the piston is out. I have check that the ring gap should be 0.012" - 0.016" at the bottom of the bore. So Boxing Day is when I pull the head and piston out and start checking everything possible that I can think of.
Now as to how this engine lubricates the piston is unknown to me as I have not had it apart so I will have a look but thought maybe running a dry sump it must be pressure fed and not splash. The high pressure oil line enters the crankcase on the crank handle side then guessing it runs through the main bearing that side then to the big end then to the 2nd main bearing and finally onto the oil pressure gauge.
Will let you know what I find or dont find soon.
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cobbadog

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Re: Lister CD8 Diesel
« Reply #12 on: December 26, 2022, 04:34:50 AM »
Started the strip down today. Radiator and fuel tank off then the oil tank as well followed by the crankcase cover near the oil tank. Once that was off I could see the bottom of the skirt of the piston and it was very wet with oil which is what I wanted to see.

Does anyone know how this gets oil on it here as there is no sign of a scoop on the conrod but there is a funny shape on the insides of the counterweights that might do the scooping?
But being a dry sump where is the oil being picked up from?

Lister win the race for worlds longest head studs. Never seen anything this long before. Head off and there is no movement in the piston at TDC or anywhere down the bore to BDC. Bore looks great with a small amount of carbon around the top which will have to be removed to lift the piston up and out.
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cobbadog

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Re: Lister CD8 Diesel
« Reply #13 on: December 26, 2022, 04:47:09 AM »
Well the head weighs a bloody ton and when undoing the head nuts 2 main studs unwound as well as one of the rocker gear studs came out. Will fix these up after a clean up and some locktite. The bore measures up quite good actually. At the top just below the carbon ring it measures 4.499" which 0.001" under standard. With the piston at BDC (about the middle of the bore it measures 4.493" which is 0.004" undersize from the top of the bore. Standard size is 4.500"

Tomorrow I need to remove this side to get to the big end bolts. Is there any thing I need to know before undoing and removing the vertical shaft which is on the governor shaft?

How do I check the fuel timing before removing this side cover or is it a fixed setting?

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ajaffa1

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Re: Lister CD8 Diesel
« Reply #14 on: December 26, 2022, 08:29:29 PM »
Unusual to find the bore is undersized, I would have expected it to be worn and oversize. Have a look at the piston skirt when you get it out, could it be binding due to lack of clearance? You could probably hone it but 4 thou is a lot to remove with a hone. I think I`d have it bored out to 4.5"

Don`t know the answers to your questions, good luck,

Bob