Losing oil pressure at end of run relief valve stuck open.

I’m running a complete Milodon dual pickup oil system with swinging pickup.
At idle I have 70 lbs, finish line 100+ at 7200 rpm using 20w50 oil.
At the end of 2016 I had the same this same issue, I replaced the Milodon 21206 cover which fixed it.

No issues through the 2017 season.

First race out 3 weeks ago lost oil pressure at the end of the run. I always shut the engine off at finish line. Restarted to go to pit and no pressure. Towed back and took relief valve cover off and valve was stuck open again. The rest of the day I popped cover and “unstuck” valve each pass.

Returned home and removed cover, removed relief valve then chucked it up in lathe to radius the edge of valve. Polished the leading edge of the valve but I could still feel the valve clicking as it slides over the inside relief valve bore to seat. Seems there is to much clearance between the bore and valve allowing the valve to drop down and the leading edge of the valve to catch on the bore opening thus hanging it up. Kinda like checking valve guide clearance by wiggling the valve in the guide.

I thought radiusing the valve would fix it but it didn’t. Another thought would be to make a stop to prevent valve from opening as far and catching.

I called Milodon prior to buying this one and was told they have never heard of this issue. Just my luck, I'm the only one..lol

3000.00 to put a dry sump on it would fix it but since I’m a bracket racer it just doesn’t make sense. Hell any of the other wet sump pumps cost half or more of dry sump, Titan, System One, P&P ect. Not to mention I'd have to do a remote filter which would add more clutter..

Anyone else had this issue and if so what is the fix. 285.00 to buy another cover to repair this for maybe 2 seasons is not economical plus it’s stupid. Anything out there other than a Milodon?

Thoughts?

Dave

Is it the 21225 or 21235 cover?

bypass the system with a Peterson external bypass valve plumbed into the pump cover and remove the Milodon hardware
If you can't easily rework it.

quote:

Originally posted by imakehp:
Is it the 21225 or 21235 cover?

It's the 21206 cover.

Dave

quote:

Originally posted by B.C.Malibu:
bypass the system with a Peterson external bypass valve plumbed into the pump cover and remove the Milodon hardware
If you can't easily rework it.

Didn't know about this.. I'll check into it.

I took the valve out and went back to the lathe. Rounded the end a little deeper and laid it back into the valve more. It slides into the bore better but I can still feel it when it enter the bore.

Just as an estimate it has about .010 or so clearance in the bore which is a lot.

For the Mopar guys here that will know what I'm talking about. If I were to take the plug from where the relief valve is, drill and tap say a 10-32 h ole. Run a screw in far enough to just stop the valve from dropping out of the bore. Do you think it will relieve the pressure as it should? There are 3 reliefs in the valve but I don't know if the valve has to clear the bore in order to work properly.

Thanks guys..

Dave

We used to do that to manipulate the pressure. Don't see why it wouldn't work as a stop. Find/make a small gasket under the nut so it doesn't seep oil.