Before proceeding further, I'll suggest that the oil pan be put in place with everything clean but without the gasket.  Then take a feeler gauge and see exactly where the distortions are between the pan and the retainer.  Once this is known, then you can make a suitable correction.
  
If that fails, I’ll suggest a thin bead of RTV and then the gasket on top of that but only in the retainer area.  You didn't mention the brand or composition of the oil pan gasket which can be a player.  I can see where cork would be a problem in your case.

Using RTV by itself without an oil pan gasket would be a mess and very difficult to clean the next time the pan would need to be pulled.  I've pulled down other brands of engines where this was done and they were still leakers at the oil pan rail which means RTV is not a cure all.   If the pan is only leaking at the rear seal retainer area, then that would be the only area I would consider putting a thin layer of RTV.  It’s important that the RTV be allowed to ‘skin over’ before actually placing the gasket on top of it.  In your case, you may need RTV on both sides of the gasket at the rear seal retainer area depending upon if the pan or the retainer or both is the problem.

Lorena, Texas (South of Waco)

Ted, Can the RTV Sealer be used in place of the pan gasket? I do not have any leakage at the 2 pan studs or at the seal holder parting line at the block. I used Coppecoat at the parting line. I have been under the motor with it running with a mirror and the leak is definetly at the pan between the seal holder bolts. When I took the pan off yesterday the gasket was stuck good at both surfaces except between the holder hold down bolts. I have cleaned up both surfaces of gasket material and will lay the pan on the block to see if it is level. I tried K/W Coppercoat on one gasket and I used NAPA Form-A-Gasket on the other two.

56 VIC  Gene Stoehr Sr.

For sealer, I use CopperCoat at the rear seal retainer parting line.  You might consider that the seal retainer bolt holes are the source of the oil leak.  Filling those exposed cavities with RTV after tightening the bolts may help in that case.
 
I’ve performed similar notching of the rear seal retainer for studs that have been used with a main girdle without pronounced oil leakage problems from that area.  I do use a thin film of RTV at the pan rail in lieu of a pan gasket when using the main support girdles.  Verify that the oil pan gasket is covering any voids that may be exposed if the gasket is not wide enough.  Also insure that the oil pan itself is straight in that area.  As a last resort, have you considered milling the bolt pads on the rear main cap just enough that would lower the nut/washer combo?  Vics' suggestion of using 12 point nuts is also a good one.

Lorena, Texas (South of Waco)

Wouldn't a 12 point nut be smaller then the 6 point one?

  Vic Correnti

I have the same leak but not the mod you have. Did you check the amount of blowby? Silly me, I thought I could block of the downdraft tube on my 56 312 and rely on just the filler breather but NOPE! when it is over 3000 rpm it leaks, no, it bleeds. I had a broken ring in one cylinder! Argh!


1936 Ford 3W Coupe : 56 T-Bird 312, 47 Packard 3 speed, 40 juice brakes.
1968 Merc Cyclone FB GT 390, Getting a better front clip!
1977 Ford F-250 Supercab RWD Explorer Long box.
1976 Chev Camaro RS LT
Future rebuild : 1949 Ford F-1

Sorry, I meant the two oil pan studs.  They need thread sealer.

I took another look.  You are right, the nuts do not clear with washers underneath on the assembled engine.  So you do need that much clearance.

Did you apply sealer to the base of the retainer, where it contacts the block?



Lawrenceville, GA

Motor is a B9AE, everything standard, looking at all the crud inside I would say it had never been torn down. I marked all the caps as to position of them. Block line bored I believe everything went back as original. Best I remember the studs were installed hand tightened per instructions with no thread cement.

56 VIC  Gene Stoehr Sr.

Interesting.  Maybe the main caps changed throughout the years.  As long as the studs have enough threads, you might have about 1/8" removed from the caps, where the washer rests.  Then use the replacement retainer with only enough removed to clear the studs.

Do the 2 studs have thread sealer?


Lawrenceville, GA

My retainer does not clear the nut. If I remove the washer under the nut it will clear. Can these washers be removed? Attached is a picture of the nut and the new retainer I have bought. I tried to fill the retainer bolt holes to provide more surface contact but so far that did not work. The leak definetly at the rear pan gasket.

56 VIC  Gene Stoehr Sr.

The retainer on my engine clears the rear man nuts.  The clearance is required only for the stud, which is quite a bit less than you have in yours.  On one other engine block and retainer combo, it is the same, the nut clears just fine, only a little is required for the stud.

Are you positive it is the gasket surface of the retainer that is the source of the leak?  One idea is to cut some shim stock to fit on top of the retainer bolts.  Make sure the shim is thick enough to be level with the retainer surface.  Glue it onto the bolt with a dab of silicone.  That may offer a little better support, for a better seal.

You can see, from the change in color of the retainer at the very back, that the gasket seal seal takes place at the front of the retainer, so material removed from that point may compromise the effectiveness of the seal.  You might also want to use a little silicone to level out the valley between the retainer and block.


Lawrenceville, GA