question Why no oil pressure on my Willys MB engine? Bristol rebuilder?

[thefoxhat]

Spent 18 months on and off fully restoring my 1943 Willys MB Jeep. Finally got to cranking the engine and firing it up but NO oil pressure anywhere.. I stripped the engine down for inspection and bore wear, crank bearings, etc and everything looked in good order. Drained out all the fluids of course. Cleaned the oil pick up and mesh screen, etc.... Oil pump inspected and again its in good order and is sucking / pumping when immersed in a bowl of fresh oil..

 

SO Question 1 - Is there something I should have done, like pre-priming the pump or filling some oil galleries? I've seen various things said on some other forums but nothing that makes it very clear to me !

 

And Question 2 - is there a person / company here in the Bristol area that could be trusted to strip and rebuild the engine as I fear I may have already knackered the big ends......

[earlymb]

Maybe this is helpful?

 

http://www.1943mb.com/c-15-G503_WWII_Jeep_Configuration_of_First_Engine_Start_after_a_Rebuild.aspx

 

Good luck!

 

Greetz

 

David

[Pete Ashby]

You don't say how long you ran the engine before you turned off ?, you should see pressure building in one or two seconds from start providing the pump has been primed before installing.

Some people use Vasaline and pack the pump on rebuild I prefer to use engine oil. I assume you removed the pump if so have you got the correct gaskets replaced in the correct order?

Did you remove the floating pick up pipe from the block flange? if so did you replace the small gasket ?, if not you can draw air and the pump wont prime.

Another useful thing to do when starting an engine after a full strip is to prime the main oil gallery via the oil pressure gauge pipe using an pump action oil can, takes a bit of time but well worth the effort as it fills the feeds to the mains and big ends

 

Why do you think you have a problem with the big ends? I'm afraid if you have knocked the ends out you may also have caused a problem with the mains and possibly the camshaft:cry: sorry to be gloomy but oil pressure is key without it the engine is toast I'm afraid.

 

Pete

[FourFox]

When re-building Jaguar J60 engines this is a commom problem. The Jaguar racing boys sometimes use thin grease to pack the oil pump so that it wiil prime OK. I just use engine oil and fill up the pump and the suction and delivery pipes to the pump.

 

A useful trick is to crank the engine with the ignition (or electric fuel pump ) switched off until the oil pressure builds up.

This can take several 10 second bursts on the starter. Thus loads on the new bearings will be much less than running under its own steam! It also gives you a chance to sort out any mis-assembly problems before major damage occurs. We all make mistakes !

 

I also liberally soak all the valve gear and bearings with heavy oil during assembly just to give the new bearings a chance before the oil pressure is primed.

 

Jon

[Richard Farrant]

Vaseline was recommended by Rover for their V8 engine due to the pump being high. I have also used it in jeep engines, as if you use oil and do not test run it in a short time there is likelyhood of that oil seeping away, Vaseline creates suction and after all it is a petroleum product and disapates once the oil is up. I usually spin the engine on the starter without plugs before starting, and watch the guage, once it flickers you know the oil is present.

[Jack]

Hi FourFox,

 

Not a problem - you need to speak with Jim Clark who owns Allied Forces Canvas and his sister company Red Ball Restorations. Jim is not far from you either 01454 261100 or 07831 378904

 

http://www.milweb.net/go/alliedforces/

[thefoxhat]

Thanks for the replies guys.

Never removed the pump in the first place so it had some residual oil in it, but the rest of the sump was drained & cleaned out, etc. Pick up was fully cleaned and the gasket replaced. I did spin the engine with no plugs but didn't get a reading on the pressure gauge (that should have been the time to ask these questions!) however we ploughed on thinking that with some revs it would pick up and pressurise quite quickly but it didn't... I guess we ran it for 3 or 4 minutes before switching of hence I am pretty sure we have ruined the bearings by now....

 

Wasn't aware about packing or priming the oil pump or how to go about it.... For what effort is involved I think we will fill the oilways via the oil pressure gauge pipe as Pete Ashby suggests - is there another way of doing this via the valve timing cover?? Then we'll start it again and see what state its in.......... If we've ruined the bearings already then this little exercise wont make it any worse than it already is !

 

Thanks for the recommendation of Jim Clark... I've been passing his place on and off for the last 12 months and kept meaning to pop in and see what they do but just thought they were canvas makers..... !

 

Will let you know the outcome in due course but probably wont be till after xmas now.......... thanks

[Jerrykins]

When you ran the engine for 3 or 4 minutes did it rattle/knock? If it didn't chances are the bearings will be ok. Are you sure the oil pressure gauge works? Loosen/remove the flexxy oil pipe to the filter you'll soon know if you've got oil pressure, have rags handy!! Don't be too hasty to strip the engine, all may not be lost. Good luck. Jerry

[commander]

I know this might sound stupid but have you taken the oil pipe off which is on the rear off the engine

to see if oil comes out I say this because I once built an engine and the oil gauge it self had a blockage

in the end so it did not register but when I took the pipe off by the block it pumped out every where

presto oil pressure sorted just a thought

Commander

[paulbrook]

When you ran the engine for 3 or 4 minutes did it rattle/knock? If it didn't chances are the bearings will be ok. Are you sure the oil pressure gauge works? Loosen/remove the flexxy oil pipe to the filter you'll soon know if you've got oil pressure, have rags handy!! Don't be too hasty to strip the engine, all may not be lost. Good luck. Jerry

 

I couldnt agree more with checking both the guage and the pipe to it - and any junctions. I also agree with the idea of undong things and sacrificing a little oil to the garage floor. Top tip though - don't do what I did one with a Diamond T. I was being towed from one part of where it was stored to another and I thought ooo I wonder if it will start? So I bunged it in gear and eased the clutch out. It fired up a treat and about 2 seconds after striking gallop I realised that the oil pressure guage was out and the pipe was just poking out of the guage socket. The moment I realised this the oil squirted out. For some reason that I cannot recall my reaction was to stick my finger over the end. All that did was change the jet of oi to a spray of oil. By heck it took some cleaning up.

 

Still. It ran and it had decent oil pressure.

 

Also on the subject of Jeep bottom ends I ran a big end on the way to Carlisle (I was taking it to the DVLA to get its registration having imported it) No problem I though, carry on quietly and once things get too bad Ill call for recovery. It got me to Carlisle and the 45 miles back (about 65 miles in all) and when I stripped it expecting all sorts of carnage it was relatively easy to sort, just a 10 thou grind.

Edited December 19, 2012 by paulbrook

[thefoxhat]

Thanks for all the suggestions.... We assumed no oil pressure because the oil filter canister never filled up and no oil came out the feed pipe joint to the pressure gauge, plus it sounded pretty awful..........

 

HOwever over the course of this week the pump was packed and refitted, the oil ways filled via the oil gauge flexi pressure pipe and via the valve cover. Today, the engine was cranked with no plugs/ignition and we got 25 lbs pressure on the gauge (oil also dripped all over the floor as we hadn't tightened up the connection on the back of the gauge either!). After fitting the plugs & connecting the ignition the engine was fired up and the gauge went up to 60 lbs falling back to 40 lbs on tickover after it had been running for a while to get warm... Stopped the engine, took the cover off the oil filter and it was full of oil as it should be. Seems as though we have cured the oil pressure problem BUT it still sounds like a flipping diesel tractor engine so I am not sure we are out of the woods just yet.............! Started the engine several times and got 40 lbs at tickover every time. If the big ends were toast then surely we wouldn't have got such good pressure? The oil gauge is a new item.

 

Then the next problem cropped up............. could not disengage the clutch and get it into gear. Fairly sure the clutch plate has stuck to the pressure plate by looking at whats happening through the inspection cover... and we couldn't break it free either....

 

So its running OK but can't get that first drive round the yard just yet..............

[scammellmark]

hi. as standard practice when waking up a rebuilt engine i leave the rocker cover off, take out the distributer and make a drive tool, i then turn the oil pump by drill( making sure of direction) and check for oil at top end, this only moves the pump, and then when oil appears you turn the engine by the crank, thus coating all moving parts. then refit plugs,dizzy and rockercover. i have looked at a rover v8 recently that had been rebuilt, it had been fitted with a high volume pump and this had sheared the the drive gear, luckerly the engine did not run, so removing the dizzy showed the problem and was run up after priming and fitting uprated gears, so i never take anything for granted. hope theres no,or little damage,

[commander]

ref the above post how do you mange this without stripping the oil pump gear drive

Commander

[Richard Farrant]

ref the above post how do you mange this without stripping the oil pump gear drive

Commander

 

I see what you mean, but some engines have the drive gear on the distributor, so once removed the pump is free to be turned.

[commander]

Richard I see ref other engines but it would be a disaster if you tried it with a jeep engine

Commander

[Richard Farrant]

Richard I see ref other engines but it would be a disaster if you tried it with a jeep engine

Commander

 

Absolutely, in other words, if the drive gear does not come out with the distributor you cannot do this trick. Another method would be to have an external oil pump connected into the gallery to prime, just like the old Meadows 27.5kva gennies, where you pumped a handle to prime the system before hand cranking.

[Scammell4199]

When rebuilding our jeep engine, or anything mechanical for that matter I smeared everything in oil as I put it together. Then did as four fox said and cranked engine with ignition off and pipe in gauge slackened till oil came through to expell air from pipe, did the connection up, cranked a bit more to check pressure was coming up. Ignition on and away she went no probs. I was going to say that we bought a new block and it had cross drillings only accessible from inside the crankcase that should have plugs in them, not sure if the wartime blocks had them but presumably so. I'm now rebuilding the Gardner 6LW from our Scammell and would like to run the pump without running the engine to circulate oil after seeing Jacque littlefields guys doing so with their panther engine but the pump is geared to the camshaft, so might try to circulate it by cranking it on the starting handle tho that might be a bit optimistic.

Glad you sorted it, Richard

[scammellmark]

hi, i understand what you mean, if the pump gear doesnt come out,then i usualy pressurize the system by the oil pressure takeoff in block, ensuring that oil appears at the rockers. let this settle and then turnover engine,lightly oiling the bores through the plug holes, then if the oil appears to be flowing,its time for a start, there are 2 thoughts on assembling engines. 1 is to oil everything too excess, and 1 is to assemble dry, this is dependant on preference. in imaculate conditions then oil everything. if theres any chance of airbourne contamination, the oil traps this and forms a grinding paste. so i assemble engines in spraybooth conditions. but when doing engine work in vehicle, i wash off all parts and reassemble dry, close up engine and prime oilways.

[Scammell4199]

Yeah I suppose you could pump oil into the pressure gauge outlet or something, the pump would act as a block in the system being stationary and force the oil to the bearings etc.

I always put things together smeared in oil and make every effort to keep everything scrupulously clean.

Richard