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. Took relief valve cover off and valve was stuck open again. Shut engine off at finish line and towed back. 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. There is to much clearance between the bore and valve allowing the valve to drop down and the leading edge of the valve catches on the bore opening thus hanging it up.

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.

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

Does the Milodon adjustable pressure relief kit come with a new valve. I've run Milodon pumps forever and never had that issue. Maybe you need to find an "Old" pump due to some oddball production changes.

Have you checked for flatness of your block to the pump housing. Maybe there is something causing a twist and bind.

Insert a 660 bronze sleeve (get it as a tube from MSC, Grainger etc.) in the cover, bring it back to the (new) valve OD). Easy access: it has a plug in the end where the passage was drilled, just follow that, alignment doesn't matter.

Sounds like the bore of the relief is your issue
and that could be cleaned up.. with a 100+ on
oil pressure you could afford to lower it some..
the valve tipping would be my concern

Or a slight oversize valve may be practical. How complex is the shape?

Titan has had the same issue, from what I have heard.

Maybe when stuff is tightened down it distorts that area causing it to stick

Maybe an Indy cover. I've put 500 passes on a used part. Never had any issues. Single line 7200 rpm.
Doug

OP, how old is that cover?
I've used over 50 Milidon of the older pump covers over the years and never had a problem like your having with yours
I have three motors with the new style pump covers for the remote mounted oil filters, one is being used on my bracket engine now with no issues so far, one is on a customers 800 HP pump gas Hemi motor that came off a engine dyno last week with no issues
I do have one motor that has the Hughes brand single piece pump cover with the oil filter mount built onto it with no issues either

the adjustable valve does not come with the pump cover - are you using the Milodon Billet pump or a factory pump - 99% of the time the pump cover is over tightened and it makes no difference with the old or new style cover - both can distort enough to create the issue

I agree...

I personally prefer the pumps that Wescott made but they are kinda hard to come by. I did have a relief valve issue with a KB pump twice. I have also had good luck with Titan but after the fire I am not sure they are available now either.

Believe it or not I k
had an adjustable valve in it Saturday. Backed out to it's lowest allowable. It blew the o-ring out of the filter. Ended up going back to the original valve.

The issue isn't in the pump itself it's the cover. Seems there is to much clearance in the valve to bore..

Dave

Sorry that isn't the issue. I can make the valve hang up with the cover sitting on the bench.

Dave

I like that idea..
And I do still have my old cover..

Dave

The valve tipping is the issue in my opinion.. I did go to a lighter oil to lower the oil pressure. Haven't looked at data to see where it is now.

Dave

Hope this works...

Relief Valve kit

Dave

I thought Indy used the Milodon cover. I was interested in their indy maxx pump but could not find any info on it. Is the cover like the Milodon?

I used to have on of the 2 piece milodon cover and only issue was keeping the gasket for the filter adaptor from leaking.

Dave

This is the second Milodon part # 21206 cover I have had this one has less than 2 seasons on it. First one had maybe 3. So in 5 years I have had 2 of these same issue..

Dave

I have had good luck with the Indy covers too. Use them for a lot of engines actually.

Do you kill the engine at the stripe or not?