Oil pressure too high

[morepower]

I just installed my 496 stroker into my 68. it has mopar .590 mechanical camshaft. melling hi volume oil pump. Using comp cams break in oil at this point and time.

with a mac tools mechanical gauge installed upon initial cold startup getting about 210 psi revving it up to keep her running

when she is all warmed up the pressure is between 30-60 psi at idle and 90 on revs.

I ballooned up one oil filter although I think it had a ding on the very end of it possibly damaging it internally.

removed oil filter and oil pump to inspect relief valve, it moves freely in pump, i did change the pump spring with a different spring from a known good pump and same thing. what else would cause excessively high oil pressure or are those pressures fine for a brand new engine with 0 miles and about an hour of run time. any info would be great and useful.

Thanks in advance

Anthony

[Challenger340]

If the Oil Pump and Relief checked out fine.... too tight of Bearing Clearances ?... or too thick of Oil for the clearances used ?

What were the Main & Rod Bearing clearances used internal of the Engine ?
The side clearance of the Rods in pairs on their respective journals ?
Weight of the Oil used ?

210 psi ??

Think of the Oiling system internal of an Engine... for lack of a better descriptive analogy.... like a length of garden hose with "holes" in it... to water, or "lubricate" areas you want ?
Too BIG of holes close to the Tap.... nothing comes out the holes at the far end of the hose ?
Too SMALL of holes close to the Tap.... and throughout the whole length.... not enough can "escape"...  so "pressure" rises within the Hose ?
NOT saying this is the problem,
just trying to explain the Oiling system theory as it relates to the questions I asked above ?

Good way to tell.... is by Oil "temperature" as the Engine is running under normal driving ?
"Pressure" is HEAT !
If Oil temps rise under driving = Too tight !
and if bearing clearances internal of the Engine are too tight, no better way to have high Oil temperatures and premature bearing failures.

This is why;
having a Stroker Kits checked out according to "Spec" by generic Machine Shops is a crap shoot ?
Show me the "SPEC BOOK" for a 500" Mopar Engine at plus 500 hp ?
Where is it ?
and if anybody THINKS "stock" 440 Engine "specs" are fine.... show me the Plus 500 hp 440 Engine specification column for machining in THAT "440" Book ?
the simple answer is unfortunately.... and my point being...
Chrysler never made a plus 500 hp 440 ? ...... so most the "specs" for a regular sub 5,000 rpm 440....
DO NOT APPLY to an Aluminum Headed, 496" Cubic Inch, Solid-Cammed, 6,000+ rpm Wedge trying for 550 or 600 hp?
Sorry for the rant....
but without knowing the bearing clearances used internally of the Engine... Diagnostics of Oil pressure problems can be EXTREMELY difficult... guessing on "supply"(pump)... guessing on bearing "demand"(leakage).

Try thinner Oil maybe ?

[ACUDANUT]

Please tell me you not running 20-50 oil.  it's too thick and won't oil everything correctly.

[John_Kunkel]

There is an assumption that the pressure relief valve can relieve any amount of overpressure but a close inspection will show that the opening in the relief valve is fairly small and there is a limit to how much extra volume it can pass to relieve excess pressure.

[morepower]

comp cams 10-30 break in oil is in the engine. cannot give you bearing specs. but yeah that is what i will look into

[Challenger340]

comp cams 10-30 break in oil is in the engine. cannot give you bearing specs. but yeah that is what i will look into

10-30 is already fairly thin oil.... very surprising that the pressure would be that high with 10-30 once warmed up ?

Do you have a sheet with the Bearing Specifications & Clearances @ Torque that were re-checked AFTER Machining... and "recorded" during final assembly ?
Assuming here,
you paid someone to assemble the Engine ?

Just say'in.... it would be REALLY nice to know internal engine bearing "clearances".... when diagnosing an excessively HIGH Oil Pressure condition ?

John Kunkel is bang on as usual.... the relief port in the pump, can NOT handle ALL the Volume relief necessary to reduce oil pressure, "IF" the pump output is more than the bearing clearances/engine will accept ?

[morepower]

when it is warmed up its between 30-60 psi and 90 on a rev

the machine shop is since gone and i have not seen a spec sheet.

[Challenger340]

when it is warmed up its between 30-60 psi and 90 on a rev

the machine shop is since gone and i have not seen a spec sheet.

That's probably why they are "gone".... too lazy, stupid, or dumb NOT to supply it WITH their work they are charging GOOD MONEY for doing !

No matter...
I will assume those "hot" numbers ? operating temp ~180* F ?
WOW !
* 90 psi would be pretty high for 10-30 Oil @ 180*
* 60 psi would also be pretty high for 10-30 Oil @ 180* as well, assuming 900-1,000 rpm idle speed ?

To confirm here
Where... or when..what "idle" rpm are you seeing the lower 30-40 psi readings ? and at what water temp ?

If the 30 to 40 psi with 10-30 oil is down around 500-600 idle rpm at 180*F ?
And the Oil Pump relief is functioning.... WITH a "patent" return port(not Blocked or restricted somehow ?)
Then,
I suspect you either have the best dam oil pump I've ever heard of ?..... or.... you have really tight bearing clearances internal of the engine ?


To diagnose further... if too tight bearing clearances are suspected ?
I would recommend getting an Oil Temperature Gauge that measures at the Oil Pan.... and run the Engine @1500-2500 rpm up and down with the high oil pressure for an extended period "watching" the Oil Temps.(assuming the Filter don't grenade)
If the Oil Temp continues to keep climbing past 200-210* F and higher..... no matter the 180* water temperature... you can then approach even "thinner" synthetic Oils ?
Std Volume Oil Pump ?
or...
too little bearing clearance repairs ?

[BSB67]

I just installed my 496 stroker into my 68. it has mopar .590 mechanical camshaft. melling hi volume oil pump. Using comp cams break in oil at this point and time.

with a mac tools mechanical gauge installed upon initial cold startup getting about 210 psi revving it up to keep her running

when she is all warmed up the pressure is between 30-60 psi at idle and 90 on revs.

I ballooned up one oil filter although I think it had a ding on the very end of it possibly damaging it internally.

removed oil filter and oil pump to inspect relief valve, it moves freely in pump, i did change the pump spring with a different spring from a known good pump and same thing. what else would cause excessively high oil pressure or are those pressures fine for a brand new engine with 0 miles and about an hour of run time. any info would be great and useful.

Thanks in advance

Anthony

Try another gauge.

What is the range on the one you're using?

I put a long rotor pump on a stock clearance motor with 1/2 groove bearings, and the pressure was no where near 210 psi.

[fy469rtse]

with plugs out can you turn motor over ,
just seems like clearances are tight, and would be excessivly tight to turn over by crank snout,
i have only had one high oil pressure engine and that was when i tried full groove main bearings
i would try another gauge first

[morepower]

the shop was well known in our area for building many race engines, when they built this engine they were doing competant work IMO but doesn't mean they didn't skimp on mine for some reason. The main machinist and owner have since had multiple strokes and he could not find capable employees and couldn't work himself the way he would like so he shut the shop down. again this engine was built 10 years ago

idling at 750 rpms, temp at 150-160F.....I was also thinking that maybe the comp cams break in oil says it has mineral oil in it and maybe with extreme pressure additives so maybe that is why...but.

the range on gauge i am using goes from 0-400psi

motor turns over very nice by hand or with starter

and i fired her up today and the pressure wasn't over 100 cold. odd.

anyway we found some metal in the filter and just to be sure of bearing clearances we are pulling the engine out again and going over everything.