oil pressure

Any ideas
today i fired up our JP1 blown methanol motor, no problem crank oil press =120 run press = 160,
running out of fuel so we shut off, toped up fuel level, crank over to start but no oil press or very low 30,
i removed the hose going to the filter and hand cranked the engine and pump seems to be working, pushing oul out of the hose,
i have drained it , removed the sump and checked some big ends, up to now all seems fine, now if all is ok on the crank side, where should i start next? oil was fine no bits!!!!

 

How many quarts of oil are you running? there's a chance you sucked the pan dry. the oil drains back very slowly on some of the hemis.

 

plunger stuck..Dave

 

10 Quarts, i will check the plunger, and put in 12 quarts cheers

 

We run 16 quarts

 

If you were only running 10 quarts that's most likely your problem. with 160lbs of oil pressure you'll run the pan dry pretty fast and the oil can't return to the pan fast enough to keep it full, most guys will run between 14 and as much as 17 quarts.

depending on your bearing clearance you may be able to slow the pump down just a little

Good luck
Scott Hohensee

 

10 quarts is definitely not enough, I wouldn't run any less than 16 or 17.

How many quarts does the pan hold, and is it a dry or wet sump system? Also, how big are the slots / holes in the top of the block in the lifter valley? If you run more oil and continue to have issues I would open up the slots to get the oil back to the pan quicker. We've seen a fair number of blocks where the drain back slots are way too small and you can never get the oil back down to the pan fast enough.

 

Cheers guys, checked the bottom end, all fine, i did swap one big end bearings as one a little worn just because i was there, checked over the pump fine,
cleaned the filter which had collected more grease than i thought, wont grease the rockers again, blew out all the lines now running 14 quarts 160 at start 80 warmdoes that sound ok? the pan is a funny car wet sump pan

 

i always leave with 120lbs never any problems always keep you filter checked ever time my filter got dirty no oil pressure i have only had it happen a couple of times kinda freakie feeling though i use lucas fifth wheel lube on the push rods it