Classic/Antique Car Repair: 31 Coupe leaking oil out rear main

Question
We have a 1931 Coupe that was leaking oil out the rear main. Have read through several posts regarding this issue, but still need a bit of extra advice.  We started with basic tests, made sure the oil fill tube was open. Oil was dripping off the bolts on the rear main. Dropped the pan and checked the oil tube on the rear main and it is open. Oil slinger looked good. Replaced shims on all three mains and all are approximately twenty-thousandths. We did not pull the engine, but used the old method of removing the shims from each cap, replacing them with new ones and removing them until the engine couldn’t be cranked. We then added one more shim until the engine could be turned. Torqued all main bolts to 80 lbs. Oil seems to be running out more now than before. Any suggestions?

Answer
Wow, it sounds like you know what you are doing and you have done all the right things. I assume you put in new rope seals, top and bottom.  Make sure the oil is not coming from the front of the crank and dripping down in the rear of the pan.  If your engine is 100% model A original, it should not leak very much oil, but it will leak a little.  We have had some rebuilt engines where "improvements" have been made in the rear main area and no one can stop the leak.  Hope that is not your case.  I'll ask my friends and see if they can offer any suggestions.  Remember that the bearing is outside of the pan and that slinger and tube were designed to get most of it back into the pan.  Someone may have made some changes in that area, mixing new and old methods and screwed it up.  The book says two things that could go wrong.  If the oil tube is screwed in too far, into the cap, the end could get blocked.  And be sure the shims are against the crank bearing surface.  I assume you have Les Andrews Red book.  Sorry I can't help you, but let me check around.  If you figure it out, let me know what it was.  jack