high oil pressure? :(

[Underwoj]

hi all - I bought a 1970 c10 back in Oct of last year and lovin it!! when I test drove it the oil pressure gage went all the way above the H and it you drive it for a bit (15-20 mins) it will slowly creep down but still like 3/4 way up to the H. He said it always did that and not to worry. Do you think this is just a faulty gauge? where wld you start? I don't know much about engines

[Lee H]

I would start by hooking up a mechanical gage and see what it says. None of the stock gages in this era were very accurate, more of an about reading. The motor was probably put together with a high pressure and or volume pump.

[19673ontree]

Probly a high pressure oil pump I put one of those in my 327 it acts just like that , they are a couple of downfalls to them but they have a great plus ! You know all your bearings are drownded in oil ! Downfall is they wear the dist and cam gear and eat up a few horsepower ,

[bob8619]

Mine does it too. I read that the reason it starts out high and comes down later is just because the oils heating up and thinning a bit. I was told in the engines section of this forum that its nothing to worry about.

[Underwoj]

nice - thanks guys!! yea the guy put a 327 in it so was hoping it was just something aftermarket that made it run high.

[Lattimer]

Depends on what engine you have also. The earlier motors with 2 piece rear main run lower pressure than later 1 piece rear mains. So if it was a nioce new crate engine, it may be a 1 piece rear main and have higher pressure.

Mine is a 1-piece and pegs the gauge where you can't even see the needle on start up. Once warmed up its right on the middle line at idle. At cruising RPM is on the high line.

My old engine showed 50 psi at cruising rpm on a mechanical aftermarket gauge, and showed right on the middle line when I installed the gauge cluster.

[brad_man_72]

Id run 5-30 in it to try to get the pressure down a bit if it bothers you. Not that the high pressure is hurting much.
My 5.3 swap reads a little high even with 5-30.

[geezer#99]

And not to forget the pressure releif valve is usually set at 65 psi whether it a high pressure or normal oil pump.

[Underwoj]

Thanks for all the info guys - great to have guys who know what they're talkin bout in here

[19673ontree]

Yep my 327 runs fine and dandy and I run 20W50 in the summer and for older engines I like the valvoline racing oil it has zinc in it if you have a 327 older engine with flat tappet cam id suggest you run the valvoline racing oil too for the cam ,, you can type this in google and read it for.yourself and it is very true ! All oils did have zinc but they dont now

[burnin oil]

My old 400sb ran with the pressure gauge barried to the right. Hot or cold the gauge was right at the high mark. It was abused by me as a teenager and when the rod let go it was still carrying 45PSI until the very last second. Definatly sounds like a HV pump was installed and has some decent bearing clerences. You could always verify with a $10 mechanical gauge if you think the factory may be bad.

[Tom Vogel]

High volume pump. Thats all.