My Buddies 598 has a HV pump and it idles over 80 goes over 90 WOT. He runs his boat like I run mine Wide open all the time his pressure never goes below 80. Another friend of mine has a standard pump in his motor and WOT pressure is over 100 if I remember correctly he had to buy a new oil pressure gauge cause the one he had didnt have enough sweep. No major pressure drop after long WOT run. Common denominator between the three motors is 50wt oil and they all have very large oil coolers mine is 3x25" bundle and I think about 30" overall. I measure the pressure after its cooled and filtered going back into the motor.

Why? What is the point for all that oil pressure aside from more parasitic drag on the pump and wear on the distributor gear? In a sub 6000 RPM motor I would think 60psi would be sufficient at WOT for anything your doing, and even 25-30 at idle would be just fine. Any more than that is just burning up horsepower in my opinion.

Run a line under the carbs, that should pull some pressure from the crankcase. Or puke tanks. The rest seems normal blower motor stuff

Burning up 8-10 horsepower or not I'd rather have a little extra cushion myself. But the point I was trying to make in the last post was about the lack of drop in pressure.

I can not tell you if I am losing 4hp from my oil pressure setup, but I can tell you my distributor gears have been wearing fine.

While my numbers are a bit high on the cold side of things, I do not consider 75-80psi at operating temp, at 6000RPM over kill. I consider 60psi at 6000RPM, "Adequate".

I know looser clearances and higher oil pressure is kinda old school, the school of thought here, was that looser clearances help keep the bearings running cooler (more oil bled out of the bearing), and the higher pressure, and higher viscosity, helps keep that wedge of oil in the bearings, especially when you are getting up there in power level, with parts that may not be "overkill'.

If you're running a blower, nitrous, things of that nature, or simply lots of power, with either an engine block not as rigid, crank not as rigid, main caps not as rigid, and so on, things can start to flex a bit. If you are tight on clearance, low on oil psi, and and the oil's film strength may not be up to the task, bad $hit happens when you lose that oil wedge and metal to metal contact occurs.

For me, I dont have a BIG M block with Billet main caps, billet crankshaft, etc. I'm running a chevy crank, in an old mark IV block, with iron caps, at 800HP with a blower. The internals are probably thinking they are 900hp considering the parasitic losses from a roots blower. I personally want to stay on the looser side of things here, with enough oil pressure. None of this may apply if you are running a 500HP engine at 5000RPM.

Those are just my thoughts, I'm no engine builder, so take it with a grain of salt.

I should have quoted out the part that I was referring to originally. I'm not talking 80 being outrageous, but over 100 at WOT?

I also referenced 60 being sufficient, which would be the same as adequate, so I think we agree there?

I think the OP is concerned about an issue that isn't really an issue, especially if it has been like this for 100 hours and nothing has changed. If he started out with 80 psi and is now running 60 psi then I would see cause for concern, but I wouldn't spend much time looking for a problem in this particular case.

I don't consider the above quotes overkill either. I just don't see any reason to run more than that. None.

But I guess just like type of oil, run what works for you.

I honestly couldn't tell you. I know the rule of thumb was always 10psi per 1000RPM as a minimum. Would 60psi at 6000RPM be adequate for a blown 1000HP marine engine? I dont know. That a question for the pros

https://www.youtube.com/watch?v=7IpJlYssvkM

My wife mentioned i wear it too much, especially in public.

She said she wanted to buff and spit shine it.

Who am I to argue ?

Love getting my helmet spit shined + buffed by a female.

And might I ask. Who took your helmet off and let you out of the corner?