Oil circulation procedure

[volker.halbach]

Terry, I am sorry. You can confirm your suspicion by blowing into the pickup pipe and blocking the copper pipe at the other end where it comes out of the crankcase. If you detect a leak there, I cannot think of another solution than to split the crankcase.

[Mick D]

Hi Terry

You can do a bit more diagnosis before you gain access to the pump, do as I and others have suggested and blow up the pipe, if it passes air easily you have a leak in the system, if it passes air when you kick the bike it has a priming problem, if it doesn't pass air you have a blockage.

Highlighting where the problem may be helps in location when you dive in deeper.

Regards Mick

[Terry.C.]

HI guy's, The saga continues.
So far I have discovered that the oil sludge trap was totally blocked Nd I did not need to strip the engine down as access was possible via the sump.
But so far no circulation of the oil even whr running the engine for a few minutes
Next technical question.
Next to the bottom of the oil pump on the left hand side there is a hole which spews out oil into the timing case.The oil spew is no where near the run of the timing chain.
Looking at Drags parts list from 1941 to 1951 there was a non return valve fitted in there part no's 81 82 and 84 nothing is listed for 1953.
It seems they replaced it for 1956 to 1958.
The question is should it be blocked off and could it be drawing in air at this spot causing the oil circulation problem?
Looking forward to your replies
Regards
T

[volker.halbach]

I am not quite sure which hole you mean. Is it a hole left to the oil pump, and you can see it with the oil pump fitted? Then that will be a hole that connects the outer with the inner timing case. It should be open.

Now it sounds more as if the problem were the supply side. If the sludge trap was full, the oil ways in the crank may be blocked. Are you sure the oil reaches the big end bearing? You can test it by removing the sump plate plus the outer and inner timing case and then pumping oil into the end of the crankshaft. If you use thick oil, it can take some time until the oil drips out of the engine sump. But if you cannot pump oil through the crankshaft, it will mean the crankshaft has to come apart.

[nevhunter]

The quill that feeds the mainshaft is not a good fit, so oil will pass into the Motor anyhow but not through the Big end Bearing. With all the Muck in that Plug the Motor Must have done quite a bit of work and perhaps not been that well serviced. Maybe forcing oil at High pressure into the Mainshaft will Move the grunge? Flush it afterwards to remove all of the sludge. If it's the Tapered Pin it won't have a Cage and will Just be crowded rollers. Chances are, the Big end is Pretty ordinary so JUST replace it. IF it's done 30K Miles it owes you nothing. Nev

[Terry.C.]

Hi Volker,
Did you mean the timing case cover fixing screw to the left of the oil pump? The hole in question is not threaded and lies directly between the left bottom cover screw hole and the pump. With the cover off oil spews out of there quite quickly and checking the cover gasket it does does not cover the hole when the cover and gasket are in position
Nev if this hole does not solve the problem your suggestion is the next move.
T

[volker.halbach]

Yes, the unthreaded hole is the one I mean. I have a prewar bike where the hole is at a much higher level. Oil should come out from there. In the case with the cam you have a certain oil level, and that flows through this hole into the outer case until that oil level is reached in the outer case.

As Nev says, oil can escape from around the quill and fill up the chamber with the cam. If the oil ways in the crankshaft are blocked, this is the only place the oil can go. I think you need to remove the inner case again and check whether you can pump oil through the crankshaft. It can take some time. Have you checked that the oil pump does pump oil? Maybe we asked this before...

[Pete.Silson]

Terry,

The hole to the left of the oil pump is a drain between the cam chest and the timing cover. If oil spews out of there, then oil is getting into your engine from somewhere (presumably from the oil tank). Even if the big-end feed is blocked, oil from the pump will bypass the quill and empty into the cam chest and run down to the sump.

With the pump removed, push an appropriately sized piece of plastic tube to seal into hole (A) and suck on it. You should get a mouth full of oil

Assuming there is oil in the sump, if you can suck air through the tube then there is an air leak between A and the sump. Even with a small air leak between the sump and your tube, you should still be able to get oil out if you suck hard enough.

If you are unable to suck out oil or air from the tube then you may have a blockage in the pipe between A and the sump so try blowing down the tube. You should be able to blow bubbles into the oil in your sump. If the pipe is blocked it can either be debris in the pipe or, as I know from personal experience, the pipe has been flatten inside the crakcase and needs replacing. Unfortunately, the latter will involve a complete stripdown of the engine. If it is debris in the copper pipe, then remove the sump and blow an airline in hole (A) which may shift it. If not, try a piece of plastic strimmer cord in (A) which, with care, it can be manoeuvred round the corner in the pipe and all the way to sump.

Pete

P.S. If you are asking a question about some particular part of the engine, a photo paints a thousand words.

[Terry.C.]

Wow Guy,s Lots of good info from you to get my head around.
Yes Pete I agree with you a picture is a great help. Unfortunatly I am not that good with computors and I do not know how to load and annotate them like you can. Any lessons on that?
One last wild thought. If I blow air into the end of the crankshaft and I get air out of the sludge trap is that any indication that oil is getting through to the big end bearing

[Mick D]

"If I blow air into the end of the crankshaft and I get air out of the sludge trap is that any indication that oil is getting through to the big end bearing"

Hi

No, all this would mean is the gallery between the crank and sludge trap was clear, a better, though not conclusive, test would be to put the trap plug back in and see if air still passes. If it passes air it would indicate that the way to the big end was open.

Regards Mick