I tried the two gauge hookup today. The second reads a bit higher but still drops to about 5lbs after warmup. Perhaps it is a bypass blocked open. I didn't put the bottom end togather on this one so I know its right. (good machinest) Should I change the oil filter to see if that bypass is the problem?  Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Chuck:

Your initial post said you had carb problems.  Did it flood?  If so, you may have diluted the oil with gasoline.  Does the oil smell of gasoline?  What weight oil are you using?

John - "The Hoosier Hurricane"

No flooding. I had a couple of old Holleys that just wouldn't adjust properly. Both need rebuilt. The break in oil is still in the engine with no smell of gas. The scary thing is this is the same engine that lost oil pressure 2 years ago. That was a bad main bearing. Everything was rechecked and machined as needed to bring it back. Bored to standard 292 with new Isky cam and lifters. My friend at the machine shop put the short block together for me so I'm sure all the clearances are correct. (this time). I hope something is holding the bypass valve a little open and causing the problem. When the pressure is low it doesn't respond well if I rev the motor. Only goes up a little. I used a new gearotor oil pump that I had on the shelf. Didn't want to take a chance on the old pump. This is frustrating!! Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Chuck:

Have you resolved your oil pressure problem yet?  I had a couple of things you can think about.  You say the oil pump was stored on the shelf for a long time.  Maybe the relief valve stuck closed in its bore, causing the 70-80# pressure initially.  Then, as it warmed and was lubricated some, it opened to the 40# level and stuck there.  Then, as the oil warmed, the pressure dropped because the relief valve was stuck open.  Check the relief valve for free movement as others have suggested.

Another thing that happened on my race car this summer.  I had been fighting low oil pressure early in the season, and finally got it right.  60-70# on startup, 40 at warm idle, 60 on the track.  One day I started it and had 45, and thought, "oh no, here we go again".  Had a small oil leak on the lower left side, rear of engine.  I found the nut for the compression grommet on the inlet pipe was not very tight.  Tightened it, and pressure was back to where it had been.  Apparently sucking air into the pump.

John - "The Hoosier Hurricane"

Thanks John. I plan to take the relief valve apart and check it. Problem is I wont be able to get to it until spring. We are setting out on a business trip this week and the car is going into storage. When I first started to prelube the engine it wasn't bringing up much pressure. Had a long wait to get pressure to the passenger side. I found that the rubber seal that fits into the oil pump had a small leak. Replaced it and the oil flow came right up. I'll recheck all the seals on the pickup when I take it down. I also plan to change the oil filter at that time. Should I take out the break in oil while I'm at it?

I really think the problem will be in the pressure relief valve. Scary thing is this is exactly like the problem I had with this engine 2 years ago when it lost a main bearing shortly after a complete rebuild. I know the bottom end was put together correctly this time as my machinist did it for me. He is as precise a dude as Ted!  Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Chuck:

Maybe I need to see a shrink to make me stop thinking about you.  My latest thought to keep you busy is this: are you using the same pickup tube that was in the previous engine with oiling problems?  How about a crack in the tube above the oil level, allowing air to be drawn in instead of pure oil?  Checking the oil for aeration and bubbles after running the engine would point to air entering the oil system.

John - "The Hoosier Hurricane"

Chuck, you say you had a new gerotor pump on the shelf. If the body is cast iron it is likely a Dynagear pump. I had lots of problems with those pumps. They had great oil pressure cold but it dropped off quickly as the oil heated up. They were made until 2005, more or less.

Dyna is no longer in business.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

Thanks for the input John. My pump is the all aluminum body not cast iron. Did they ever pinpoint a reason for the drop in pressure? Chuck 

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Finally back from the business trip. I changed the oil filter today and the oil pressure came up. It still seems a bit low but it is a stock pump. Starts cold at 40 idles hot at about 15. Also when I rev the engine the oil pressure goes up (wasn't happening before). So I guess the WIX filter had a bad relief valve in it.

Does anyone have the high pressure spring kit for the oil pump? Or is there a trick to changing the relief spring to increase pressure? It seems we used to stretch them but I can't remember the details.

Engine sounds very good and runs well. I have to get the final tune done on it and see what it will do. Question, does the MSD distributor operate on full vacume or ported? There was some discussion about it at the shop today. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

You can shim the spring with flat washers. Go slowly. I over did it once and blew the gasket out of the filter.