Im putting this post up for a friend of mine. Me I'm into Mopars ( Hey we all have our down falls).

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

Altering the relief valve spring should not be necessary. Make sure the plunger travels smoothly along the bore. If it is getting caught somewhere, the pressure will increase as you rev the engine and something will have to give.


Lawrenceville, GA

We did check to make sure the plunger in the relief valve was moving freely, and it was. It does have a new melling # M42 oil pump. We cant even get the motor to run more than 30 seconds or so before it blows oil.

Thanks

Ray

What weight oil are you using? Does pressure go past 80psi?

I had ones same problem and I found that the relief valve plunger in oil pump was there wrong way.


Tero from Nurmijarvi, Finland

56 Country Sedan, 61 F-100, 61 F-600, 55 F-620, 52 Mercury

http://www.dlc.fi/~teros

http://www.y-block.info

http://www.hollowheads.net

http://www.fordnationals.net

good morning 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.

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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

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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.

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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.

Lorena, Texas (South of Waco)

Weight of the oil he is using is 10/40 ( Not my choice ). Oil pressure goes from 0 to 80psi with in seconds.

Ray

A 10w40 is a good choice. sounds like the spring in the oil pump is simply to strong but yet could be something else as Ted suggested.

-Gary Burnette-

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