johnlo

I have a twin engine 32' Baja with 502's bored out to 509's. When I run the boat above 3500 rpms for about 5 minutes the port engine starts to show lower oil pressure than the starboard engine. When I come off the throttle and idle the port engine oil pressure drops down to 15 lbs. while the starboard shows 35 lbs. I already smoked an engine because of this problem, had it rebuilt, changed the oil pump, and still having the same problem. The engines start at the exact same pressure, the oil guages and sending units are new. When running the boat hard the headers and the oil filters feel exactly the same on both engines, and both engines run exactly the same water pressure. I'm stumped, anyone have any ideas????

CMS Racing

Frist Run A Mechinal Oil Psi Gauge. Then Check Oil Temp With A Inferred Heat Gun With The Boat Running At 3500 And Above.you Mite Have To Big Of A Bearing Clearnce Or A Bearing Getting Ready To Let Go. Food For Tought.cms Racing Engines

FlyFast

John,

Is the cam and lifters the same in the motors with low oil pressure. I have done the same thing. Had a motor with low oil pressure. Rebuilt it with a new block cut the crank 10 under, new oil pump rebuilt the motor with the same cam and lifters and came up again with low oil pressure. The only thing untouched in both builds were the cam and lifters. I know my lifters put out alot of oil because I can see it in the valve cover.

This is my wag. Maybe my lifters are adjusted too tight. Does anyone think it would be worth my while to put in new lifters? Any other ideas?

RedDog382

Do you have oil temp guages? Sounds like the oil might be overheating at higher rpm's. Maybe a blocked oil cooler?

FloridianSon

Mine does about the same thing run WOT for awile pull back fast and the pressure seems to drop off more than if I slow down and giver her a chance to cool down slower. If I run the RPM's up a bit she comes back to about where she should be.At WOT my oil temp is 260*.Maybe I don't want to admitt I have a problem so I think that the parts have expanded so much due to the WOT that there is more clearence and real thin oil.Just my .02 James

MACDAD260

I think RedDog is headed in the right direction.

Tinkerer

Blocked oil cooler or stuck open pressure relief valve on the remote adapter.

FloridianSon

No blocked cooler on mine.260 WOT and 190 returned.I monitor both