Babbit oil groove?

[rexrogers]

My A has a huge oil leak, i dropped the oil pan again today to make sure the return tube was free of obstruction. After some searching on line for some remedies i decided to pull the rear main cap and check th babbitt. I found ou that the oil galley didn't conect. I cleaned out the passage and checked the clearance. My question is would this causes my leak

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[James Rogers]

Possibly. Check the thrust, it can cause a bad leak also.

[Glenn C.]

The face of bearing cap and the cap mounting surface needs to be very clean and flat. Use a very thin layer of Anerobic Sealer between the cap and block mating surfaces. Do not use Silicone sealer for this particular application. Anerobic sealer is used for aircraft crankcase sealing purposes.

[rexrogers]

I just got back from a 12 mile test drive. I added some copper mesh to the oil fill tube cap my car has the breather tube on it already but i figure that it wouldn't hurt.
I still have a few small drips from the flywheel cotter pin but it looks like cleaning out the grove and rechecking the rear shim clearance worked. I messed up and completely forgot about using any sort of sealer on the main cap, some anaerobic sealer would have been ideal.
I think for the time being i will put the oil janitor on and just monitor the situation.
I am still a new bee when it comes to the model A.

[duke36]

For what it's worth, I'd remove the copper mesh as it may restrict blow by. Do you have a flex type breather diversion pipe that connects from the top of the stock breather/oil fill tube?

[PC/SR]

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A "few small drips" is normal. I would take the mesh out of the filler cap because the mesh can restrict crankcase pressure release. Dont worry about no sealer. I would have connected the two grooves, but its done and seems to be working OK.

[Kohnke Rebabbitting]

Originally Posted by rexrogers

My A has a huge oil leak, i dropped the oil pan again today to make sure the return tube was free of obstruction. After some searching on line for some remedies i decided to pull the rear main cap and check th babbitt. I found ou that the oil galley didn't conect. I cleaned out the passage and checked the clearance. My question is would this causes my leak

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First of all, the Babbitt was poured to cold, as you can see the holes in the Babbitt which is caused by sluggish, under temp. Babbitt, as the Babbitt will pull air down in the pour, and will harden, leaving holes. It will be even worse on the back side, next to the casting.

The Babbitt shows no signs of peening, so the crank is left to pound the Babbitt to the cast iron, cracking it with hair line cracks that you can't see from the bearing surface, until it gets worst. With out peening the clearance opens up leaving a bigger space for oil leaks, and less lubrication.

The bearing was poured with a jig that had the groove made right on it, and also the oil wells. As you can see the jig was of poor quality, the oil groove never filled out all the way, as it should have, cutting off the oil supply, as if it had no groove at all.

The oil wells are too small, not going clear to the cast edge of the bearing, where they should be.

End play should be .003, and not over .004. If over .006, fix it.

Herm.

[George Miller]

Also that cap has poor contact at the pass side rear of the cap. It is going to leak oil. To me it looks like a very poor babbitt job.

[rexrogers]

I pulled the copper mesh out. I do have the flex tube breather on the car. THanks for the info on the babbitt. I have another block that i am in the process of tearing down and slowly rebuilding for more of a touring motor for the car. After you guys had mentioned the condition of the babbitt i compared the two rear mains and i could see the difference.

The more i drive the car the more my to do list grows and it is out growing my pocket book right now. For now the leak is minimal and will continue to check on it. Next project on the the list is to for a full tune up check the timing compression etc. I would like to pull the pan off again and go through all the bearings and check the clearance and babbitting. there are few shims on each so i might have room for adjustment there.