Re: Low Oil Pressure 356

Posted by Owen_Dyneto On 2014/6/14 14:52:23

If you do as HH56 suggests with a good quality mechanical gauge and the pressure is indeed low (should be about 45 psi at road speed), the first two things I'd check, given the engine work you specify, is:

1. Thickness of the oil pump cover gasket. You want the thinnest possible consistent with sealing the cover. An excessively thick gasket will just allow the oil to short-loop within the pump cavity and never reach the galleys. I usually make the gaskets from notebook paper - 0.003 - 0.005" thick.

2. Examine the oil pump cover to see if has a wear pattern from the rotating gears. If so, it gives the same result as too thick a gasket, the oil just loops within the cover and never enters the outlet stream. If there is any wear pattern you can feel with a finger nail, take the cover to a shop and have it resurfaced.

If the max pressure you can get with a cold engine and proper viscosity oil is 40 psi or less, I'd shim the spring on the pump relief valve with a thin washer (no reason but buy a new spring) and aim for a max pressure of 45 before the pump relieves the pressure.