Toooo high oil pressure

Finally fired up the long rested '67 Camaro 327 tonight, fired up first try at that, checked my oil pressure gauge (mechanical SW) and it read 80psi, which is as high as it reads! This was at idle and when warm! Now all I have done to it was refresh the stock '462' heads, a Comp Cams Magnum 292 cam and lifters, Comp roller rockers. Now I DID put in a Melling MV55H high volume oil pump. When I got the engine it hadn't been run for a while so I didn't know how it was going to act. The bottom end was gone through at one point, it has .040 over pistons in it. Now 80psi at idle is a little too much for my liking. I also have a screw on oil filter adapter and have heard about problems with them and filters? Or a byp*** sticking? I'm going to switch in a normal OEM style oil pump tomorrow, should I look for anything else while I have the pan off? I just don't want to grenade this thing so I'm taking any precaution I can.

 

was the block cleaned before the re-build ? maybe a clogged up oil galley ? something is causing too much pressure (obviously)

 

Same thing happened to me, pressure got so high it started squirting oil out around to oil filter gasket. It turned out to be the byp*** valve in the oil pump. If I remember right it was over 90psi at idle. Hope you figure it out soon!

-John

 

The block was super clean when I took it all apart and I cleaned it out before I put it all back together. It looked like it was at least taken care of before i got it. My gauge only reads to 80psi and it's pegged. I guess I'll switch in an OEM pump and try it out tomorrow, I just want it to be at a safe pressure. Should I take off the oil filter adapter and clean it or check any other places that may be an issue or does everyone think it's probably just the pump? It sounds GREAT, just want it to last!

 

Wait for Squirrel or one of the other expert engine guys, but I've heard of the adapters causeing trouble too. Can you put the canister back on?They are actually supposed to be a better filter then a spin on.

 

Did you check bearing clearances? Or did you just ***ume the other guy did things right?

 

stuck relief valve in a pump that was in storage. not common, but not unheard of. I have had to unstick a few.
thick oil on a cold day?
don't rev it up until the oil is warm. I have seen a couple oil pump driveshafts snap off when the engine was revved up and the oil wasn't given time to warm up and thin out a bit.

 

A high volume oil pump will pump the pan dry if you don't have a deep pan. If you want more pressure than stock, either stretch the spring in a stock pump, buy a different spring, or High Pressure Pump. Also a High Volume pump has a taller body on it, and your screen may be pressed against the pan

 

A high pressure pump isn't a great idea. A HV pump shouldn't be high pressure unless that valve is stuck.

 

Check with another oil pressure gauge.
Mike

 

That much pressure is too much. I have the same pump on a 350 and it's around 45-50 at idle and 60-70 at redline. Over 80 on startup sounds like something is wrong. What weight oil was in it?
With that much pressure, if there is decent volume behind it, you will drain the pan dry and all the oil will sit in the valve covers.

 

We "normally" shim the byp*** spring to get MORE pressure - because it's that spring which controls EXCESS pressure - bearing clearances, plugged gallery - none of that will matter IF your pressure relief isn't functional.

FWIW - I just bought a NOS pump for my HEMI - when I took it apart I found that the pressure relief piston was STUCK. Seems that over time that oil in there turned to glue and whamo - would have made things real interesting if I hadn't found it.

Check the pump first. IMHO

 

A high volume pump won't pump a stock pan dry unless the return system is unmodified and it's held over 6k. Definitely not at idle.

Is the oil filter adapter byp*** plugged off, or is it still functional? I plug mine for full filtering, but ya gotta stay on top of the filter changes. Point being, if yours is plugged off the filter could be the restriction and it's easier to change than the oil pump.

Hate to say it, but know the other occasion I've seen sky high oil pressure? Spun bearings that were about to reveal themselves with noise in the next few minutes of operation.

good luck

 

A high volume pump won't pump a stock pan dry unless the return system is unmodified and it's held over 6k. Definitely not at idle.

It won't at an idle, but it will under power. Oil restrictors should be used if solid cam, but I have been through this before, stock pan should be junked if using one. Everyone is going to have there own opinion, but I have dynoed using all different type oiling systems, intake systems, different cams, have seen alot of ****. To each his own, but I will stick to what I have seen...

 

The reason HV pumps end up producing excessive pressure is that they are designed for race motors with increased bearing clearances. When they are used with standard clearance motors the pressure is raised because they are trying to pump too much oil through too small a space. Washed out bearings aren't unusual and with SB Fords the dizzy drive shaft can be twisted clean off. Something I found out in a personal way.
For a street motor get a standard vol/pressure blueprinted pump.

 

bearing clearances wont make that kinda pressure thats pretty insanely high. If you rebuild a pump or have a high flow pump the byp*** can be driven in too far. you definately have a pump problem, or a couple plugged oil gallerys. clean new oil, and if the pump is under warranty you shoulkd send it back for a replacement OEM pump. high pressure pumps are terrible ideas in a street motor, they work good in blower applications and thats about it. high volume is the way to go if you have something thats a little more than stock such as your case. some people think its all the same but its not.

 

what kind of oil pressure guage do you have? If it is a mechanical guage verify that it is good by swapping with a known to be good guage. If it is an electric guage verify that the sender and the wiring is good. I have seen electrical guages that the sender wire was grounding and that caused the guage to be pegged.

 

And where is the pressure reading coming from?

 

high pressure pumps are terrible ideas in a street motor, they work good in blower applications and thats about it.

LMAO

 

Well I think you need to experience it then because you're wrong in your thinking. I've seen it first hand on a BBC that had a screwed up crank regrind. The clearances were checked but not all the way around. Some of the throws were somewhat egg shaped and the pressure was ******* an 80# gauge (so no idea what it really was)on that also. Took out the cam and dizzy gear

 

I've seen cam bearings to tight do the same thing also, but very rare I guess. You see some crazy things when you hang around machine shops long enough.

 

If you are getting enough oil to the top end then it is a good chance its the oil pump. I would check it was another gauge first before tearing it down. Sound like the byp*** valve is stuck. Been there before. Had an oil filter blow of the motor when we were reving up the motor.

 

Update fellas. I put on an OEM oil pump today, fired it up and it read 70psi cold, let the engine warm up to about 185-190 and it was reading about 60psi. It used to be a canister style filter, but the guy that had it before me put a screw on style on. I'm getting my pressure reading from the port right behind the intake manifold. The gauge SEEMS to work fine, I guess I could try another one I have laying around. I pulled the valve covers today too and there's plenty of oil too. What should I check now, or do you think 60psi would be ok? I haven't driven it or anything yet, this is all warming up sitting there at idle.

Oil is Rotella T 15-40
Gauge is Stewart Warner mechanical

 

If it were mine, I would say it would be fine, just keep a watch on it. If it has a straight shift, I would let it warm up, push in the clutch, put her in 1st., Turn her up to about 6500 hunerd, side step the pedal, and start pulling cogs, but thats just me........LOL

 

I had a 350 that had high oil pressure like that. It came already in a project I bought. It was strong and reliable, and I put many thousands of miles on it before I sold that car. Not sure if it had a hi volume oil pump or what the deal was...

 

Hahahahahaha right on! I'll just watch it I guess, it sounds healthy, we'll see how it goes down the road! Should be good to go now!

 

I built a 350 several years ago with the M55HV. 80 psi before broken in, or at temperature. After 20k miles and using 10w40 Valvoline, idle at 35 to 40 psi, highway speed at 75 psi.
Learned something else with that engine, rod bolts will stretch and break if reused enough times. I'll pay the money to replace the bolts and have the rods resized.

 

Sounds pretty much like my 32 roadsters 47,000 mile 462" Buick.
Equipped with the high volume oil pump kit and a higher than normal relief spring.

75-80# when started from dead cold.
That's on the carbs electric choke high idle cam.
I can usually tap the throttle and the high idle cam backs off a bit, rpm comes down and pressure is 60-70#.

Driving away easy and cruising down Hwy 66 @ 40 mph, pressures are 65-75# until the engine gets some heat in it.
Ambient temps are 40 - 50 degrees.

Keep in mind that if your coolant temp gauge says 180* the oil can still be pretty damn cold and that's the reason for high pressures when warm.
I can get on the freeway with the coolant at 165 - 180*, but oil pressures remain 10-20# over what they will be when the oil is fully warm.

Oil is Pennzoil 20-50 wt.
I usually swap to 10-40 in the winter, but this winter I think I'm changing over to Mobil 1 synthetic.

This time of year, once the engine is up to temp - about 55-65 degrees ambient in the afternoon - pressure settles in at 47-50# at 3000 rpm which = 70 mph.

Idle rpm = 500 rpm and with the engine fully warm oil pressure is 15-20#


I'd say you don't have a problem.
Drive the car, get the engine fully warm and see how it does.

The only thing I would caution against is revving the engine when it's still cold.
You can get past 80# and above 100# and that's where some oil filter cannisters can split.

Not good they tell me, especially dangerous to the health of your checkbook....

 

Drive it and see where it's at after 100 miles. Go 10 miles on the freeway to get the oil temp up, and see where the pressure is when you come to an idle afterwards. Running it in the driveway only heats the water, not so much the oil. It's not gonna BLOW UP. High pressure's a bit tough on the oil pump shaft. So don't drive it hard. But, the motor's not gonna blow unless something ELSE is wrong as well

 

One more thing. People read to much into all this oil pressure stuff. In 1970, if you ordered instruments in a 70 Camaro Z-28 (and other models) you still got an idiot light for the oil and instruments for everything else. Unlike prior years when oil was included in the instrument option. Reason was almost what's covered here. One guy's got 60lbs pressure in his Z-28, and his neighbor had 80lbs. Monday morning they BOTH show up at the dealer. One thinks his too high, and the other thinks his too low. BOTH demanding an explanation (or new motor under warantee). So, in 1970, no more oil pressure gauge as part of the gauge option. Some of my baddest Pontiacs have only 15lbs at idle. If your motor blows, something else was ****ed up besides a 10-20lb discrepancy in oil pressure I ***ure you. Too much oil pressure is an issue that went away with the spray on babbit motors of days long gone. Peace out