Too much oil pressure?

[drive_55_not]

Is there such a thing as too much oil pressure on these 3v's ??

I installed the FRPP M-6600-F46 oil pump a couple weeks ago and I didn't think there was any difference in the pump other then the 90psi bypass spring so I didn't swap it and I'm getting some crazy high oil pressure.

I have an electric 0-100psi oil gauge and it's pegged at cold startup, it's running 75 cruising at 2000rpm and warm idle is 50, and back to pegging the gauge at WOT.

Motor is definitely burning oil on startup and loosing oil while driving. Lost a quart of oil after 6 dyno runs last week, down another quart from DD this week.

When I get a chance in a couple weeks I'm going to swap the new pump backing plate to the old pump but just curious if it's possible to float a bearing with too much oil pressure?

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[skwerl]

Are you running 5w-20 or something heavier?

 

[drive_55_not]

Been running Mobil 1 0w-40 for 40,000 miles,, With the other pump I was seeing normal pressures,, 80psi cold start, 45psi cruising and 25psi hot idle.

The issue with the old style GT500 pump I was running was it loosing oil pressure @7000+ rpm from the back plate flexing.

I did swap from Cometec head gaskets to the FRPP Felpro gaskets and comparing the holes before installing them.. the FelPro gaskets were 'missing' some but they appeared to be for coolant passages.


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[BruceH]

Pressure is a measure of resistance and flow. If I was in your shoes my main concerns would be the lower bearings and the valve train. Keep in mind that the oil has to maintain positive separation between your bearings and crank down low and it has to pass through the galleries to the top end where it has to maintain positive separation between the cams and journals. It also has to keep the lifters pumped up and operate the phasers. All of this is calculated by very smart people who come up with the oil pump and oil specs along with all the other clearances.

I don't know what the perfect balance is to obtain this other than to run 5w-20 at factory oil pressures.

We could extrapolate that the GT500 runs almost the same clearances with 5w-50 and the high output oil pump so it's probably ok. The main differences would be the different valve train and differently sized oil galleries (probably) along with the higher output pump.

It will probably turn out ok. I'd think that the odds are with you.

Edit: I just saw that you are forged which means you might have different than stock clearances anyway so I'd think that the odds are more in your favor.

 

[swflastang05]

My motor has similar oil pressure right after an oil change, not quite as high as yours but it will be about 90 psi cold start up then around 40 psi @ hot idle, then after a couple hundred miles it settles down a bit to around 75 cold start and 30 hot idle, 70 +/- psi cruising . I also have the 13' GT500 oil pump with TSS gears and OEM 3v spring. All of my bearing clearances are within OEM spec, on the very lose edge of it but still within spec. I run Driven 5w 40 / DT40. I wouldn't be too concerned with it.

 

[Pentalab]

Motor is definitely burning oil on startup and losing oil while driving. Lost a quart of oil after 6 dyno runs last week, down another quart from DD this week.

Ok, why is he losing a qt of oil after just 6 dyno runs, then another qt a week later ? At that rate, you wouldn't need an oil change, ur already changing the oil on the fly.

 

[eighty6gt]

I was thinking of seeing what a machine shop could make a backing plate for, then you'd just reuse your regular 3v innards. You'd need all those countersinks and a ground surface, I can get the piece laser cut but it would be more than an entire melling pump.... Maybe?

 

[drive_55_not]

Ok, why is he losing a qt of oil after just 6 dyno runs, then another qt a week later ? At that rate, you wouldn't need an oil change, ur already changing the oil on the fly.

Yep,, I changed the oil one quart at a time on a couple of the old cars I had in a younger life ... But don't wanna do that on this one, and it wasn't loosing this much oil till I swapped the pump, heads and head gaskets.

I'm figuring the high pressure is blasting a lot more oil onto the cylinder walls and it's being burned off. I did use Total Seal AP rings but after 4yrs I don't recall exactly which ones ..

I took some comparison pic's of the old COMETEC gasket to the FRPP gaskets,

The Cometec definitely has some larger oil passage holes so I'll presume that added restriction is what's causing the high pressure.

I came within a gnat's ass drilling out those holes, I really don't wanna R&R these again but if swapping the pump doesn't drop the pressure I may have to.


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[JeremyH]

Pressure isn't crazy I would see 90-100 on cold start with same pump and the 10w40 I was running when I had oil fed turbos. I went back to 5w20 now and its back to where it was on the stock pump.

 

[Pentalab]

Switch to 5W-30 or 5W-20...........then see if pressure drops a bit.