Low oil psi 454 500HP
 

I have a 454 was previosly a 330hp now new cam, dome pistons . etc 500hp motor. I just fired it up and has low oil pressure, cold its 36psi but at 120f-140f its around 28psi.. I revved it up to 2000 rpms and its stays around 27 psi- I dont feel comfortable running the boat for the first time with these #s mercruiser says min 30 psi at 2000rpm
The boat has morel lifters and scorpions rockers, i am getting steady ticking out of them when my head is 2 feet from the motor, thinking its maybe the low oil pressure, i put my fingers on the rocker while running and it has a some oil but not squirting everywhere..
My plan is to put hv pump in this week, could it be any other issues?
using k n oil filter
put mechanical oil gauge

:eek:

I do not know if this is your problem but did you upgrade your oiling system?
Did you reverse the oil lines?
How about the valve on the oil pad?

i didnt update system or change the valve on oil pad. maybe it could be stuck open??

Did you replace the oil cooler and lines.. If not that is prob your problem.. Never re-use oil cooler and lines no matter who clean's them. If you blew up a motor before then it will have crap in it that will only ruin your new motor.

Chris

Teague on tech in powerboat just answered a very similar question last month. I dont have the mag handy though.

I never blew it up, it ran great just rebuilt and put in cam and new 781 heads.. Could it be the valve were original oil filter goes

Sounds like you missed a bunch of steps. If you are reusing the stock hardware from the 330 you will be breaking parts for a while. Upgrade your oiling system before you every launch the boat.

Spent 6 hours last night ripped motor or and replaced oil pump with a melling high volume. Which was the same pump in it. This motor use to have perfect oil pressure with the oil system it has, regardless the new pump did the exact same pressures, the boat is on the trailer now and staying cool 140f so I cant see that as a prob, were could the machine shop have left out oil gallery plugs???? Bc under valve cover there's some oil but not squirting.

What engine block do you have. There are three oil galley plugs behind the front timing chain upper gear. There also may be three plugs inside the lifter valley just above the camshaft. If these plugs are left out the oil pressure will be low, the oil will still be captured inside the engine and not leak out. Who assembled the engine, check with the machine shop that did the work and see if it is their practice to leave galley plugs out, or if they normally install all the galley plugs. Provide some information about the year and generation of the block you have. All other galley plugs will leak oil out of the engine. Good luck.

Did you ever try a mechanical gauge?