FlyFast

SBC vortec non roller. I was reading the other thread about getting oil up to the rockers and mine had the most squirt out of the front two cylinders when I went through the motor a couple of years ago. I set the rockers up cold using the timing marks and then checked the compression of each cylinder to make sure they were not too tight. Every cylinder was pumping 160 psi. I did this cold because of the hasel of taking off the rocker covers.

This engine has always had the oil pressure on the low end. If I were to warm up the motor and then use the running method of loosing up the rocker until it clanks and then tighten it a 1/4 of a turn could this give me more oil pressure? I know I am not loosing power but can you loose oil pressure from too tight rockers?

Thanks

Reed Jensen

In a nutshell... NOPE.... your oil pressure will remain the same.

cuda

Reed is right, oil pressure is dependant on the main and rod bearings.

Reed Jensen

Oiling systems in engines are basically controlled leaks. The oil pump forces the oil under pressure to critical areas... the first areas to receive oil are the main bearings of the crankshaft... through the cross drilled crank the rod bearings are oiled. Some people get "hung up" on pressure figures. But oil is "incompressible".. so all pressure oiling systems have a pressure relieve valve built into the oiling system.The reason for the relief valve is the oil pump has to be large enough to supply the engine with pressure and flow at idle... but at the same time it has to be able to "bleed off" the excess oil that is pumped when the engine is running at higher rpm's.. With exception of the lifters pumping more oil at higher rpm's ( if they are hydraulic ).. the clearances of the engine remain the same.. So the oil flow through the clearances is "static". When air becomes entrained in the oil... the tiny bubbles can be compressed.. also when the oil is hot it flows through the clearances easier. Hence... lower oil pressure when running hard. But the average rule of thumb is 10 lbs pressure for every thousand rpm's... so if you have 50 lbs at 5000 rpm... you are getting plenty of oil... 10 lbs at idle when hot is adequate also. Some European automobile engines because of poor design are forced to run higher pressures to get oil out the the camshafts and cam lobes through tiny passages... Case in Point.. Aston Martin DB4, 5, and 6 engines run about 100 lbs at 3,000 rpm when hot... and that is with 20-50 oil... those old engines are famous for spinning the front main bearing if the oil flow and pressure are not adequate. Be thankful that Chev motors are happy with 30 lbs max ... no matter what the rpm. The biggest problem I've seen with oiling systems on boat motors is too thick of oil...too cold, and too many remote accessories... Remote filter.. remote cooler.. and all the distance with the lines... you can have great pressure at the pump ... but the flow is terrible because of the resistance of pushing the oil all that distance with the pump driven off the distributor.So the remote oil filter housing will have 75 lbs of pressure... but if you were to measure the oil pressure at the front of the engine after all the internal leaks through the clearances.. you may only have 20 lbs.