540 BBC Oil Pressure Problem

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09-09-2015, 08:55 AM

#11

donzi matt

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Quote:

Originally Posted by U4ICK

No I did not check the bearings since the obvious problem was the oil pump pickup. The oil pump is a CP Performance BBC high volume blue printed pump part # 250-OP-BB-B. As you can see from my OP sig, I have a large 10 quart flat bottom dual trap door racing oil pan and not the standard oil pan where all of the oil is in the back of the pan. So static pump suction pressure is less. I have a 3" X 16" CPP oil cooler, part# 620-550, and a remote located K&N re-useable SS oil filter mounted on the transom. There are four 30" oil hoses that connect the oil cooler and filter to the motor. So my oil system has virtually no back pressure other then the motor. My oil temperature runs approximately 190°F. If I have a bearing issue, I would think it would be obvious from idle to my max RPM so far of 4500. The motor is still going through break-in and I'm varying the RPM from about 3,000 to 4,500. I only have 3.3 hours of actual run time on it.

Ed

I know you probably don't want to hear this, but after reading what you have for an oiling system, you are certainly running lower oil pressure than most would be comfortable with. When you put this motor together you had 80 psi, then 60 psi, and now you have 30-40 psi. Something is going on here. In a marine motor that is under constant load, losing oil pressure will very quickly damage bearings. I certainly do not want to create unnecessary work for you, but ignoring this may lead you to a very early catastrophic failure and a very empty wallet.

If this was my boat, and keep in mind I am a very lazy person at heart, I would pull the motor again, pull the pan, and check all the bearings and crank just for peace of mind.

06-27-2021, 12:32 PM

#12

getrdunn

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Old thread however rather than starting a new one thought I’d post to bring back. Recently witnessed what can happen when a pick up falls off at higher rpm. Don’t assume anything and expect the worst and maybe you’ll get lucky. Not in this case with a virgin Merc Racing sci engine. The weld in two spots was pretty much useless and the pick up slid in and out at ease. Surprised a bolt on retainer isn’t protocol with all marine engines when considering the pounding they take especially extreme offshore.