Oil leak

I'm with Kube - it surely won't hurt the situation. Another potential is for there to be an issue on the rear cover that bolts to the block behind the flywheel -- it has a thin gasket and potentially there could be a leak in this area. Other than the oil galley plug (underneath it) and this cover, the only other place oil could be coming from is the rear main.
 
Bored&Stroked, I watched the leak with the engine running, and applied a shop vacuum suction close to the road draft tube, it stopped the oil flow. It seems if the oil was from a pressure source, such as the plug or plate over the pump to cam gear the vacuum would have no effect, but it completely stops the flow. I hope to drop the pan and find something obvious. We'll see.
 
Road draft tube?

Oh, by the way, be certain the breather at the front of the pan is "open". The correct pan gasket goes around this area.
 
Bored&Stroked said:
I believe in order to change to the newer type seal, the crankshaft has to be replaced any/or modified? I'm thinking that the 'slinger' cannot be used with a rope type seal? I believe it can be ground off . . . but obviously that is taking the whole engine apart. I don't know of an easy solution . . . but I also am not sure exactly what is causing the issue?

What oil pump is in the engine - how much PSI?
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From page #61 through #66 of the Techno Source ... below


"Rear Crankshaft Sealing

From 1932 to sometime in 1941, Ford used a non-contacting crankshaft thin flange that whipped oil into block and rear main bearing pot metal channels to prevent oil escaping. However,since there was no crankshaft to material seal, i.e., rope seals; leakage could occur due to crankcase pressure or just pour out if the engine was tilted to the back such as parking uphill"

Glenn
 
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37 truck said:
watched the leak with the engine running, and applied a shop vacuum suction close to the road draft tube, it stopped the oil flow. It seems if the oil was from a pressure source, such as the plug or plate over the pump to cam gear the vacuum would have no effect, but it completely stops the flow.
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Could there have been enough vacuum that air being sucked in through the weep hole is what stopped the flow?
 
An update, I made a pan "diaper" to catch the oil and drove it under varying conditions for 20 minutes. In that time it pumped out over a quart of oil. Next I started to remove the oil pan, but can't quite get it out, hangs up on front crossmember, and can't get the front any higher. I did notice that the pan gasket behind the oil pump could be allowing oil out. I don't recall the oil pump to block having a seperate gasket, should it? Could pressure oil leak out there and be the culprit? Pulling engine next, and that is a PITA
 
Pulling the engine won't be as much trouble as you think. I had the engine, transmission and rear end out of my '37 tudor in about 6 hours. I was working by myself until I needed a hand for a few minutes with the engine hoist.
 
You may be able to pull the pan by rotating the motor. Either #1 or#5 rod bearing caps may be causing the hangup.


Firing order is 1-5-4-8-6-3-7-2
 
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37 truck said:
An update, I made a pan "diaper" to catch the oil and drove it under varying conditions for 20 minutes. In that time it pumped out over a quart of oil. Next I started to remove the oil pan, but can't quite get it out, hangs up on front crossmember, and can't get the front any higher. I did notice that the pan gasket behind the oil pump could be allowing oil out. I don't recall the oil pump to block having a seperate gasket, should it? Could pressure oil leak out there and be the culprit? Pulling engine next, and that is a PITA
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NO gasket where the oil pump bolts and mates to the block......WITH that said....I do use a O-Ring in the chamffered groove just under the flange of the oil pump (8BA pump) and just inside where it fits into the block. IT certainly doesn't hurt any thing AND its a seal that keeps oil up in gear chamber and stops ANY potential oil getting out from where the oil pump bolts to the block. Less than a $1 and can't hurt anything!!!!
 
Just an update, I pulled the engine, pulled off the pan, and have found no smoking gun. I still have the flywheel to pull off to check the cam to oil pump cover. The pan to block and around the cork seal at rear bearing all looked really good. I will keep trying to solve this leak situation.
 
What oil pump do you have in there ? With the engines with a slinger at the rear I like a stock pump and a rather tight clearance on the rear main crankshaft journal.
 
Oil dip stick is correct, and I only use 4 quarts of oil at each change. I installed the "standard flathead pump by Melling" sold by Speedway. I can probably check the rear clearance with plastigauge.
 
I have not found the issue yet but have eliminated some things. The oil leak is not from the cam to oil pump cover or the plug in the end of the oil passage in the block. Using compressed air I can get oil to bubble around the pump at the block, and hear it at the timing gear going past the flat spot on the pressure valve. At this point it seems to be either too much oil pressure, too much clearance on rear main bearing, or too much blow by from rings not having completely seated. I will keep digging.
 

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37 truck said:
I have not found the issue yet but have eliminated some things. The oil leak is not from the cam to oil pump cover or the plug in the end of the oil passage in the block. Using compressed air I can get oil to bubble around the pump at the block, and hear it at the timing gear going past the flat spot on the pressure valve. At this point it seems to be either too much oil pressure, too much clearance on rear main bearing, or too much blow by from rings not having completely seated. I will keep digging.
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543076
 
You could try a stock lower-pressure pump - as it currently appears to have the later 49-53 pump - which will put out more volume and pressure than stock.

While I hate to mention an alternative direction, but here goes.

You already have the engine out of the car, so why not think about pulling the crankshaft, having the slinger ground off and switching over to the later rope-type seal plates? You'll only have a few more hours of work to do this . . . and it beats putting it all back together (even with a new pump) - only to see the same problem once again.

Or just put a later crankshaft in it . . .
 
A little update on this oil leak problem. I pulled the engine, removed the pan, put all new pan gaskets in, replaced the oil pump with a rebuilt original style pump from Third Generation. New lip style seal at front of crank. Built a test stand to run it on. The replacement pump lacks the built in pressure release that the Speedway pump had. No significant leaks at front or back at start up, but oil pressure jumps to 70 lbs. at start before settling at 50 at about 1500 rpm and 40 at idle at operating temperature. Thinking a thinner oil might help, using 20-50 VR1. Could perhaps bypass some oil pressure at the rear of the block with a valve? Just don't want this puking oil again.
 
I know you mentioned in post #35 that you could hear compressed air passing through the flat spot in the original pressure relief valve at the front of the motor, do you still have that relief valve operating as normal?
Your oil pressure should not go above the pressure that is set to. 70lb seams a bit high, but it may have been the first time it unseated. If you still have that relief valve set up with an original spring etc. that is all you need. You don't need fit an extra "valve" anywhere. But you do need a relief valve somewhere in the system.
 
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