I have a new GM crate 350/290HP (Edelbrock manifold and 600CFM). I put Castrol SL 10W30 and the correct amount of Redline engine break in additive. Standard oil filter adapter. At idle it's 50 psi oil pressure and as cruising RPM over 80 psi. Huh? I never had this hppen and thought I'd see if anyone has any comments.
sounds right. Tight clearances in a new motor, high pressure spring in the pump would easily make 90 psi on a fresh oil change. Run it.
my motor at idle has 45 lbs and on the road it runs at 80 lbs pressure and it has 3000 miles on it. It has a high volume pump in it.....
What oil pump do you have? Nothing wrong with high oil pressure xcept for the added strain on the distributor gear.
A couple of the late model chevy trucks i've owned seemed to run about the same psi if that meens anything. BTW how do you like that motor so far?
Plain old crate GM 350 @ 290HP. It is their low buck long block engine with factory aluminum pistons and a hotter GM cam. I don't recall pressure this high before but it's been 10 years since I bought one. Would the oil additive have anything to do with it or maybe this is just the way it is?
I love the motor and cannot think of a better way to go. You can't build one for the price and the cam sounds great with the sprint style headers and 3 1/2" side pipes I have. I have it in a small coupe with a TH350 and it idles like I am trying to hold back a team of galloping horses. Maybe not so with other exhaust setups but i sure like what I have. Stumbled into it by dumb luck too so it's even better. Sixty miles so far and zero complaints. I'm thinking with this engine they may have added a bigger oil pump spring?
I used one of these in a Camaro a couple of years ago. It's a great base motor. Probably what GM should have used in the 78-81 F-body to begin with. That oil pressure isn't surprising at all. The later model stuff runs more pressure. It's not surprising at all that they would raise the oil pressure in crate motors.
I have the same engine in my '54 chevy pickup, when engine is good and warm (10miles freeway) I get 20lbs at idle and about 53lbs at 75mph (3000rpm), I also run 10w30 but the valvoline VR1 racing oil. Pressure has been like this since new 15000 miles ago and has not changed. When the engine is cold your numbers seem about right.
I actually just put the exact engine in my truck and i got around the same pressure as well. I love the engine and the sound is very nice. I don't think it can be beat for $1800
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