OPA

JUST FINISHED REBUILDING 2 454'S
TOOK THE BOAT FOR THE FIRST RIDE, WHEN I STARTED THE MOTORS I HAD 60, LBS OF OIL PRESSURE RAN THE BOAT FOR 1/2 HR CAME TO AN IDLE AT 600 RPM'S I HAD JUST UNDER 20 LBS OF OIL PRESSURE IM RUNNING 30 WT OIL (VALVOLINE) WILL A DIFFERENT WT OIL HELP THE OIL PRESSURE ?


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Krumbsnatcher

I'm curious what was the problem with the motors before they had to be rebuilt? Was it lack of oil pressure?

Heat will allways create a lack of oil pressure, I know i just grenaded a motor last year in 15 minutes, the boat mechanic must of had some shop worker with limited knowledge assemble my motor. It had the same characteristics, fine at idle then very low oil pressure, let it cool and up it came back.

The bad news is when i pulled the motor it completely destroyed my crank and the berings were like little chips of granuals everywhere.

Is yours comming back. What is your oil temp? I think in your case it is probably oil wt. I boat in extremely hot weather so I use a 50 wt out here.

Be cautious, I included a picture of the damage i incurred with the same symptons.

OPA

THE REASON I REBUILT THEM BOTH IS BECAUSE I WIPED A LIFTER OUT IN ONE OF THE MOTORS AND DECIDED TO FRESHIN BOTH OF THEM WHEN I TOOK THE MOTORS APART THE BEARINGS ALL WERE FINE

Johno

Krumbsnatcher,
I don't feel so bad now, my HP 500 (rebuilt by experts???) last 1hour. Managed to save crank. Start all
Watch those pressure over again & I shoud be running this weekend 2month delay. Started with great oil pressure & slowly dropped down & then the knocking started
Later John

Krumbsnatcher

Ok so we know we can break these motors, now how do we find the answer for OPA?

I now have mine rebuilt and back in the boat, still not running the big dog, hopefully soon summer is starting to cook the lakes.

bobby daniels

Try and run a mech. gague ,alot of problems are sender or gage related !! I run a #4 braided or cloth braided line to the fron from the front main as this is the point that looses oil first and I can really tellthe pressures then ,its critical to say the least ...

Change to a 20w50 or 15w50 and it will fix the problem if its oil related (READ THE POST ON HERE OIL TEMP IN BBC) its good on oil problems
What bearing clearances are you running ?? what type oil pump I like the mellings HV pumps they work great or the manley pumps
high volume ones are even better
but the guys are right temp does it in if ,if the rest of the motors fine ??? let me know I'll try and help

Smitty

iTrader: (1)

I run straight 40 weight Castrol racing oil. Mercury recommends at least a 40 weight oil.

bobby daniels

WITH A WHIPPLE OR SUPERCHARGER ENGINE MAN USE SYN OIL EVEN CASTROL SYNTEC IF NOTHING ELSE sorry about caps ,,, you need that added protection as above chevy even uses syn in their hi-po cars which takes half the abuse of a blown or NA boat motor
just 2 cents worth

solid weight thickens as it cools and thins alot as it heats ,muilt vescosity works much better to protect you investments

OPA

I WILL CHANGE THE OIL AND LET YOU KNOW

Cignificant

20 pounds at idle after a hard run is not bad, especially with 30wt. Isn't the old story that you should have 10 pounds per 1000 rpm? Any idea what the oil temp is?