330 hp 454 is about 40 idling when cold, then runs up to about 50-60 psi on takeoff, then after warms up 30-40 when cruising. when hot idling 10-20. about 100 hrs on engine.

The 454 in my 71 vette is 70-80 psi when cold, 60-70 when driving, 20-30 idling hot. not sure of miles on the engine.

I always heard rule of thumb 10 psi per 1000 rpm. sometimes at 4000rpm on the boat I am around 30 psi when hot.
This is with AMSoil 50 w synthetic. Should I be concerned.

Whats your oil temp?

couldn't tell ya. But would like to know. Where do you hook up a sender for a gauge?

One of mine runs those numbers....My oil temp is 190-200 crusing @ 3000 and 225+ after a very hard run.

I think the press is to low for shure when hot.

The temp sender you put on the oilfilter ?!

Thats where mine is.

But not shure on a 330.

Also i would run 20/50 straight oil not synt.

Yes, you have a problem. The oil pressure numbers should be more like the Vette"s. Has the pressure been that low since the engines were new or has it been dropping lately?

I've only owned the boat since June so I don't know how long its run this way. Prev owner said engine only has about 100 hrs on it. The boat was overpropped(25p), it was only hitting 4000rpm wot...so maybe he lugged it too much and shortened its life. I ractheted down to a 22p prop to make it a little easier on the motor.

The only way to really know then is to pull the engine and pull it's oil pan. If you ran it easy, you might get a lot more time out of it. However, if you run it hard, you run the risk of sticking a rod out the side of the block. It's a lot cheaper to fix it before something breaks.

Thats what I would say too, I had issues with oiling early in the season with 2 new engines, I have since redone both engines and run 75psi cold, at idle, and now have 45-50 after a good run, oil temps have not went over 200 yet at all, i run valvoline VR1 20-50 .

I have also had people tell me that 50-60 at idle cold is OK and 10-20 idle hot is ok, I was not comfortable with that so I did mone, funny thing is that i have a friend that runs Merc 1075's and he has 52.2 cold and 15-25 hot, that is on a digital readout and all merc controlled.....I would think that is not enough but they are dry sump so maybe it is different, i assume Merc knows and they are 1075HP!!!!

It's a good possibility that the engine was rebuilt with slightly larger clearences and just needs a higher volume oil pump.The Melling hv pump also has the bypass set for higher pressure than a lot of the Merc. original equipment. Unfortunately that means pulling the engine to check.