[timemachine]

i know there is a million oil pressure questions in here, but here is one more. oil pressure seems to be the scariest thing when driving these kind of cars. here goes. i have a 468 big block chevy with stock bearing clearances (.0028-.003), rod side clearance is a bit high on a couple journals at around .025-.027. i have a cast crank and gm rods, and the engine only has about 300-400 miles on it. i run a standard volume oil pump, a k&n oil filter, run 5w30 mobil 1 conventional oil, and have an auto meter mechanical guage. when i start the engine, it has around 55 psi oil pressure. when it gets hot at idle in drive, it only has about 18-19 psi oil pressure at a 750 rpm idle. i have a solid roller, so it makes a little noise, but nothing else unusual. is this ok for oil pressure? should i maybe run thicker oil? if so, what grade? could the oil filter be causing low idle pressure? i havent tried thicker oil yet, but i live in the suburbs of chicago, so i would think winter would be too cold for 20w50. the car is not driven in the winter, but i plan on at least taking out the distributor and keeping the motor primed every now and then. thanks for any help.

chris

[Jmark]

Your bearing clearances are a tad high for a stocker engine but not real bad. The side clearances are not really an issue.

All things considered, 20 pounds at hot idle is fine. 55 max is fine too. You could try a different filter but I don't think it will make much of a difference. A thicker oil might boost it a little too but again, not enough to make a huge difference. Personally, I'd leave it alone.

Mark

[ChevelleSS_LS6]

1. don't use fram filters.
2. thicker oil might help oil pressure a little bit.
3. 10psi for every 1000rpm is a good rule of thumb. example: 2000rpm=20psi, 5500rpm=55psi. I think this would be different for newer engines, but yours isn't.