I have a 1941 half ton pick with a 216 ci engine with low oil pressure. At initial start up with the engine at 1500-2000 rpm, the engine oil pressure is 30 psi. As the engine is reaching normal operating temperature, the oil pressure gradually drops and levels off at 4-5 psi. At idle the engine is running with 1-2 psi. The engine looks like it has been rebuilt because I can see with a borescope through each spark plug hole, that the cylinder walls have fresh hone marks. The valve train has been worked on as well.
Is it normal for a 216 ci engine to run with such low oil pressure?
If it's showing any oil pressure at all at hot idle, consider yourself lucky. Hot cruise pressure should be around 10-15 PSI. Main bearing oil clearance will have a lot of influence on oil pressure, as well as cam bearing clearance. The connecting rods have no effect on oil pressure, since they are spray-lubricated by jets built into the oil pan that squirt a stream of oil into the rod dippers as they reach the bottom of the stroke. The troughs in the pan are only for idle lubrication. Part of doing a correct engine rebuild is aiming the spray nozzles properly with a factory alignment fixture. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
That sounds normal. What's your oil pressure when you're at highway speed? It should be around 15psi.
I've put over 2000 miles on mine in less than a year and it idles at around 7psi and runs at 15psi. At cold startup it's 30psi. It's never been rebuilt.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
At one time, one of the resto-ripoff parts sellers used to rent the aiming fixture with a ridiculously high deposit. Aiming the rod spray nozzles WILL NOT improve the oil pressure however. It will only prevent rod bearing failure at highway speed. I'd suggest checking the condition of the main bearings and the oil clearance on them. It should be as close to .0015" as possible. Good condition main bearings can be adjusted by changing shims between the main bearing caps and the engine block. If the mains are badly worn, it's time to remove the engine, as the upper bearing shells are extremely difficult to remove without dropping the crankshaft down over 1/2 inch. Worn cam bearings will definitely require engine removal and a full engine disassembly.
With a little creative plumbing, a higher volume oil pump can be fitted to a 216, one for a 1954-55 235 engine. I believe the part number is a Melling M-29.
partshawk.com/melling-m-29-engine-oil-pump.html
Those engines were designed to run straight 30 weight oil. If you're running some kind of water-thin multi weight oil, you can't expect to see much, if any oil pressure. I'd suggest running either 15W-40 or 20W-50 oil. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Cuzz Fuzz We always used a garden hose,60 years ago you had pans available.Just yesterday fired-up my 48 2-ton 235 dipper even cold I don,t think it got over 15 lbs. of oil pressure,ran good though. I often haul 15'000 gross with it,peeled the head off 2 years ago to fix a tight guide on no. 5. Ended up putting a 216 car head back on with new hard seats,all done at home. Told you wrong nearly pegged the gage cold ,hot idle 6 or 7 lbs.
