My buddy has a 1956 Merc 312 he bought it from a guy who had it sitting in his front room since 2001. New, rebuilt everything. The engine is truly a work of art. I have added a picture of it to this post. We went to fire it up a couple of weeks ago the motor fired right up and in less than about 20 seconds it blew the seal around the oil filter adapter. He has one of those canister to skrew on oil filter adapter kits on it. We fixed the seal tryed it again and this time it put so much pressure into the filter it lifted the filter off the block. Both times oil pressure went from 0 to 80 psi in nothing flat. I got on the web found a few things and pulled the motor. We did find that the shop that built the motor did have the 2 shorter main cap bolts in the wrong spot, thought that might be it. Reinstalled the motor tryed firing it up today same thing blew oil out around adapter kit. We have checked to make sure the oil pressure relief valve was in right, and it is. Anyone have any thoughts. Can you cut a pressure relief valve spring down to drop your pressre?

Any ideas or thoughts would help. Thanks.

Ray

Thanks

Ray

i think i'd pull the valve covers ( easy enough to do)to see if oil is reaching the top end.

nice looking valve covers

also consider turning oil pump by hand

stu

What’s the high value on the oil pressure gauge? If the gauge values stops at 80 psi, then try another gauge that gives a higher value to confirm exactly how high the oil pressure really is. I run up to 100 psi pretty regularly on the Y’s and no issues with blowing gaskets or filters. You didn’t mention the brand of oil filter and there are filters out there that are problem prone when it comes to pressure or free flow filtration. The Wix 51515R filter has a heavier shell and is designed to handle higher than usual oil pressures. I typically have no problems with the standard Wix and Motorcraft oil filters with most stock pumped applications.

The oil relief valve installs with the stud on the valve going into the hole first and then the spring going after that into the hollow of the relief valve. The assembly is then held in place with the threaded plug. If this is how the assembly is installed, then the oil pressure relief valve is installed correctly. At this point, check that the oil pressure relief spring is stock and hasn’t already been replaced or shimmed too heavily. For the georotor pump, the relief valve spring tension is 9.2-10.4 lbs at 1.800”. For the spur gear oil pump, the relief valve spring tension is 9.76-9.84 lbs at 1.56”. Also check that the relief valve itself works freely. Additional oil pump specs are at the following link.

http://forums.y-blocksforever.com/Topic22717-3-1.aspx

Also verify that the oil filter plate is not deformed and not sealing tightly to the block. With the oil filter plate off of the engine and sitting on a flat surface, the center hole should be raised above the flat surface at least 1/16”. Anything less than this and the plate needs to be reworked so that adequate pressure to the block sealing gasket can be maintained. Also check that the plate itself is not warped.

If everything else checks out, then it's worth the time to double check the lengths of the main bolts in the oil filter side of the block. If those are too long, then they can block the oil gallery to the mains themselves and drive the oil pressure up.

Ray

When we had the motor out the first time we and found the 2 rear main cap bolts not in the right place we turned the oil pump over with a drill and did get oil to the top end.

Ray

the reason i enquired about to end oiling was because i was thinking along the lines of what Ted told you.too long a main cap bolt intersecting the oil gallery. other possible restrictions contributing to a higher oil pressure could be rocker shafts installed wrong or centre cam bearing not aligned correctly. but as you have oil up top maybe you are ok

i agree with Jepito 80 psi should not blow filter seals. i stand to be corrected on this but i believe those seals should be installed dry??

good luck

stu

Hey Ted

The oil pressure peaks at 80psi. Right now the motor is out of the car so I will have to wait untill we reinstall it to try another gauge. I did give my buddy the oil filter# you sugested to use ( he was running a fram ). The pressure relief valve was installed right and moves freely. When you talk about the main bolts are talking about the rear main bolts ( shorter ones ) or are there other concerns about the length of the other main bolts?

Thanks Ray

Any of the main cap bolts on the oil filter side of the block being too long would be a problem.  Those particular bolt holes intersect with the oil gallery at each location.  Just insure that the bolts themselves do not extend into the oil galleries and subsequently block the oil flow.  If the bolts are original then there is likely no issue but at this point, assume nothing.