^^ That was true with the 326 engine. I missed what motor you have. But if it was a 326, changing the pistons, heads, cam, lifters, push-rods, guide plates (to the 389 style), should net you reliable 350HP easy.
Pontiac engines are NOT known for weak oiling to the top end. In fact, they usually get so much oil up there, there have been restrictor devices fabbed over the years by racers to keep more oil in the sump! If all is clear and free of gunk, it will be fine.
The 326 top end was not oiled through the push rods. There are oil passages through the head that pass the oil through holes in the rocker studs to oil the rocker arms. The hollow rocker studs are weaker then that solid rocker studs of the 389. The top end oiling of the 389 is much better. You can convert a 326 top end to a 389 oiling system by changing the push rods, lifters and rocker studs, but you can't go the other way.
Yeah. If it's a stock guage, they can read high. 70PSI at cruising speed is kinda high. How accurate is your guage? Do you have other sins of excessive oil pressure (leaks, etc)? How high does it get at 4000 rpm??? Generally speaking, a standard oil filter will bypass the element at around 60-70psi. Pontiac also has a bypass port and valve at the oil filter housing, meant to allow oil flow if the filter gets clogged. So if you're running 80PSI sithout a superduty valved oil filter flange, you will be running unfiltered oil. (the 455 Super Duty ran an 80psi pump). What viscosity oil are you running? 10W-30 should be fine. How cold is it running, etc. If you have no symptoms other than a slightly high guage reading, my advise would be to leave it alone. You probably do not have a problem.
Okay, you guys got me wondering. My oil pressure gauge indicates about 70 psi at 2700 rpm, seems high to me. The motor is a 76 400. Thoughts?
Could be the builder put a high pressure pump in it... call him and ask what is in your engine for oil pump, cam, rocker arms, etc. he should've given you a complete list of the build with the car.
1967 GTO; Gulf Turquoise on Black, 4 speed, buckets SOLD
1967 Camaro ss/rs 350
1966 Chevelle SS 396
1966 Chevelle Malibu
1970 Chevelle SS 396
1962 Impala SS
1952 Chev 2 ton flat bed
1938 Chev coupe
Gauge is a Classic Instruments quad, the fuel, temp and amps all seem to be reading correcty so I ass-u-me the oil pressure is as well.
I'm using Valvoline VR1 for oil, that's what the previous used and I'm thinking it may be good for the Edelbrock heads. I also remember the rule from "back then" about never changing oils...
I'll call the guy that built the motor, he put just about everything else in it so I wouldn't be surprised. I want to ask him about the pistons anyway, I know it was bored but don't know what kind of pistons they used.
Thanks Amigos & Apologies to Wingnutoaa for the "thread jack".
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