How much is too much oil pressure?

I just was curious if you can get too much oil pressure? I have a sbc that's pretty fresh, and cruising it runs about 60psi. Idle is between 20&40ish depending on rpm. It has a high pressure/high flow pump in it too though. I figured someone would know the answer here pretty easy

 

If your V/C gaskets are hanging down in strips all over your headers and a look in the rear view mirror seems to indicate you're at the wheel of a diesel, your oil pressure could be too high.

60 is ok for a fresh engine.

dj

 

Sounds perfect to me.

 

Cool, that's what I thought, just wanted to be sure. I guess I am use to old worn out engines. Never had a nice, well built one, lol!

 

Louie Unser built a motor for one of our race cars once (O/T Rally Car) and when we fired it up it pegged a 100 lb gauge. He had us pull the pump and he reworked it for about 75 lbs at 8,000 RPM

Aside form the possibility of Hydraulic lock up, more pressure than needed is just causing tons of parasitic drag, using up horsepower. It will also cause excessive heat from friction and premature oil pump failure.

For what it's worth, my buddy Basement Bob works in a NASCAR engine shop and says they run about 50 psi on the Superspeedways at 8,000 RPM

 

My 350 SBC runs around 60-65, idles around 40, never had any issues

 

If it was a rally car it probably had an oil cooler perhaps an additional oil filter. What was reworked and why?

John

 

For most purposes hot oil presure should never be over 80 psi at max revs. Over 100 or so tends to be real hard on bearings.

 

I have 2 different SBC in the shop right now, both built into almost idenical mild performance engines (street rod stuff) from 2 different engine shops. Fired both for the first time last week, both are running around 80lbs of oil pressure. Seems a little high to me but not my warranty!

 

as long as you can keep gaskets in it without pushing them out, I'd say she is perfect!

 

I had a tall deck 427 Chev that was in a jet boat I bought that made 80lbs. Ran on race gas, now resides in my dads 64 Elcamino

 

John, It was a Mitsubishi Twin cam motor (actually made by HKS) and what he did was modify the pressure relief spring so that by 8,000 it was no more than 75 psi when cold (around 50-60 at 220 degrees oil temp) and it would not go over that all the way to the 10,000 RPM redline.

 

This might stir someone up, but while we've got a good crowd in here for this thread, what is your recommendations for oil weight? I'm in the carolina's so pretty warm most of the year, although like everywhere else right now it is cold!!!

 

Why would oil pressure push gaskets? If the crankcase is vented properly, and it should be, oil pressure's not working the gskts.

 

This question makes reference to the term "Hydrodynamic wedge."
When the crankshaft spins, it drags oil with it, which creates a "wedge" of oil
which raises the rod and crank off of the bearing. Too much oil pressure can wipe out this effect. I have run as low as 20 PSI ( But consistent) pressure with no ill effect.
I don't recommend that low. but you also do not want the pressure to be too high.

The pressure you have is fine. And that is the reason for the builders wanting to lower the pressure from 100 psi.
just my $.02.

 

That's the problem I'm having.....pushing out gaskets.

Changed cam, not bearings, and my oil pressure went from 65 pounds to 80........................still can't figure it out, but oil leaks everywhere............not idling, but as soon as i drove it..........stench and smoke.

Finally got them all stopped, except fuel pump block.............that's next.

 

i run proabbly close to 100 PSI on my stock car engines cant rember but you will wear distributer gears with a ton of oil pressure
my gears were heavily indented after a year or two, just replaced them ocassionally was cheeper to buy new mallorys than buy new points , might not be too good for a hi miler street engine

 

I had a 283 that I stretched the oil pump spring too far. It had all kinds of oil pressure, you could peg the oil pressure gauge on acceleration. Adjusting the solid lifters with the engine running was a real mess. It never hurt anything the engine ran just fine and no oil leaks.

 

With a new engine in Myrtle Beach I'd suggest 10W30.

 

10w 30 no issues.

60 pounds of pressure on my SBC

 

I run SAE 30 and get 55-60 in a 57 year old 235.

 

I think your gauge is broken.

 

Could be, it's also 57 years old. Should be about 45 lbs huh?

 

My stroker small block Dodge runs 70-75 Psi when its cold at an idle ,but its got a high volume pump.Has 120 passes on the motor with no issues ...

 

There's no "set" oil pressure. All motors are different. Up til '69, Chevy had oil pressure gauges in their gauge pack option. People would compare their Chevy to a neighbor or friend with higher oil pressure and demand a new motor or a repair from the dealer under warantee, even though there was no problem. In '70, if you ordered a gauge package option on a Chevy car, there was no oil pressure guage. Just water temp and ammeter

 

I've always heard 10 PSI for every 1000 RPM. Too much oil pressure can pump a lot of oil into the heads that can't make its way back to the pan as fast as the pump can pump it back up. I wouldn't think you would have an issue at 60 PSI. I know in some set ups people restirct the oil that is going up into the heads to protect the bottom end.

 

I use Rotella T 15X40 diesel oil, has zinc already in it...been using it for years, never a problem

 

the weight of the oil depends on MANY variables...in the south, such as the carolinas, i would think 10w-40 or 20w-50 would be ok to run as the heat gets right up there....if you are constantly highway driving at 60-70mph and hit 3000 rpm while doing it, i would definitely use the higher weight oil...i have used 20w-50 quaker state racing oil in all my engines since the mid 60's and have had NO failures...i also add a container of duralube every other oil change - this stuff is extra protection (especially for the bottom end) and really works....personally, i get a bit edgy when synthetic oils are used as they tend to run lower oil pressures...some guys love em tho.

 

Thats what i have always heard as well "10 psi for every 1000 rpm".I know sum serious Mopar racers that fine tune there oil or blend weights so they can optimise performance .I know one in particular that likes to only see 10 psi on the return road after a pass .He is running low 9's / high 8's in the 1/4 with an all motor street driven Mopar ,so he may know something .BTW i run 20/50 Castrol in my Dodge with a half a bottle of Lucas oil stabilzer each time ...

 

That is what I thought too. That is what I used this last time also. Seems to work real well, I'm just always second guessing myself.