80 pounds of oil presure

[jrbronco]

ya i said i am getting 80 psi out of a semi buit 302.The guy i bought it from did head work pistons and big cam.I don't have spec's on any of it.The engine has may be 50 miles on it.MY ? is why would i have so much presure.What would be a good valve cover to run,because the oil drips out between the valve cover and the block.

 

[SpareParts]

80 psi is pretty high, the motor sounds like it is clearenced realy tight and has a high volume/high pressure pump. My built 351W only has 60 psi cold and realy warm usually only drops to 55 psi or so. I have has problems with my cam gear with this much pressure, I'm almost certain you will too. My other concern would be turning the motor very fast. There is not alot of room between the crank and the bearing for oil if it is clearence that tight.

David

 

[broncnaz]

I get 80 psi on mine when cold I'm running a HV pump I've never had a problem with cam gears or anything else. Since the engine is new I'd hold off on any changes but plann on changing the oil soon as assembly lube may be causing a higher than normal PSI reading. As for valve covers stockers are usually fine it may either be loose or the valve cover is bent from over tightening you could pull it and straighten it. Also the cork gaskets that are commonly used on valve covers will swell up after a while and the leak may stop.
Id wait till I had close to 5000 miles on the engine before determing that the oil pressure is to high.

 

[Broncobowsher]

I know new cars that push over 110 PSI cold when reved and idle with 10 when hot. So I don't see it as too alarming.

What kind of oil pressure do you get after then engine is fully warmed up, that is the oil is hot too not just the water?

Probably just stick some 5W30 in there, cut down on some of your pumping losses and live with it. Old racers rule, at least 10 PSI per 1000 RPM.

 

[fordguy]

i am running 80 on my 5.0 (new block with reground crank, reconditioned rods). The tolerances are really close, not a bad thing as long as is it in tolerance allowances too tight and the engine will not crank easily 5w would be a good oil to run like was said above if the pressure bothers you

 

[SpareParts]

Not to hi-jack, just wondering. Like I stated before, I keep eating dist. gears. I have the Comp. Cams 4x4 extreme cam, I have talked to them and they said that its due to the 60 psi oil presure? The motor has 6500 miles on it and I was going to pull the dissy back out to check it shortly. I has chewed one up around 1500 miles and the next probably at 3500.

Any ideas?

David

 

[trailpsycho]

Are you running the correct type of dizzy gear (Cast vs Steel)? That would be what I would be examining at this point.

 

[Steve]

Not to hi-jack, just wondering. Like I stated before, I keep eating dist. gears. I have the Comp. Cams 4x4 extreme cam, I have talked to them and they said that its due to the 60 psi oil presure?

Any ideas?

David

I can't think of any reason that high oil pressure would destroy distributor gears. That just makes no sense at all. My fresh 302 runs 80 psi cold and 70 or so when warmed up and driving. No problems at all.

As for valve cover gaskets, they aren't exposed to oil pressure so that has nothing to do with them leaking. Get a set of good rubber ones, use sealant sparingly and make sure you don't overtighten the bolts holding them on.

 

[Skiddy]

Not to hi-jack, just wondering. Like I stated before, I keep eating dist. gears. I have the Comp. Cams 4x4 extreme cam, I have talked to them and they said that its due to the 60 psi oil presure? The motor has 6500 miles on it and I was going to pull the dissy back out to check it shortly. I has chewed one up around 1500 miles and the next probably at 3500.

Any ideas?

David

My brothers was doing that also but faster, if you do have the right gear on it. his was that the timing gear cam loose

 

[broncnaz]

Not to hi-jack, just wondering. Like I stated before, I keep eating dist. gears. I have the Comp. Cams 4x4 extreme cam, I have talked to them and they said that its due to the 60 psi oil presure? The motor has 6500 miles on it and I was going to pull the dissy back out to check it shortly. I has chewed one up around 1500 miles and the next probably at 3500.

Any ideas?

David

I would lean towards the cam gear being ground wrong unless you were eating dist gears before the rebuild. Then you may have a block problem or you need to shim the dist so the gear has the correct contact pattern but this is really rare in SBF's

 

[73stallion]

i'm running about 75lbs pressure at startup. i did shear one roll pin on the dizzy gear, but i haven't linked i to oil pressure yet, as i was running the same oil pressure in my last engine and had no problems. if it happens again, then i'll look at removing my HV oil pump.

 

[treetopflyer]

I had a 289ci in my 64 fairlane rebuilt to "mean" blue print spec's went with 262 grind Comp cam and Accel breakerless distributor, & high vol. oil pump. I ensured I had correct dist. gear with both Comp cam & Accel. Oil press cold-95+, warm-80. Drove the car less than 700mi and car died! Culprit? Excessive oil press resulted in Dist. gear eating the cam and breaking teeth. Replaced hi- vol pump with standard pump (40psi hot) No abnormal wear after 45,000 miles when intake was removed for update...Personal experience...this can happen.
Moo!

 

[Broncobowsher]

I can't think of any reason that high oil pressure would destroy distributor gears. That just makes no sense at all. My fresh 302 runs 80 psi cold and 70 or so when warmed up and driving. No problems at all.

As for valve cover gaskets, they aren't exposed to oil pressure so that has nothing to do with them leaking. Get a set of good rubber ones, use sealant sparingly and make sure you don't overtighten the bolts holding them on.

High oil pressure (typically high volume pumps on tight bearings) takes a lot of effort to turn. That higher effort places more load on the distributer gear. Bronze gears were an old racers favorite, they don't care what kind of cam you are running. but the downfall is the wear out fast.

High oil pressure when cold is common and to be expected. What's the oil pressure when it is hot that matters.

 

[Steve]

High oil pressure (typically high volume pumps on tight bearings) takes a lot of effort to turn. That higher effort places more load on the distributer gear. Bronze gears were an old racers favorite, they don't care what kind of cam you are running. but the downfall is the wear out fast.

True, but I would think you would be hard pressed to find a bronze gear on a newer distributor nowadays.

 

[Broncobowsher]

True, but I would think you would be hard pressed to find a bronze gear on a newer distributor nowadays.

They still sell them, people still buy them. It worked 20 years ago on a....%)

 

[SpareParts]

The reason it wears on the Dizzy gear is it turns the oil pump. I don't think I have excessive oil pressure either. The pattern in the gear is perfect, it just wears the gear out. The teeth get thin from top to bottom. I never ran the block before the rebuild, but it was a running motor. The cam gear was tight both times, after the first time I changed the dist., thats when I realized it was wearing. The pick up went bad, and I changed the whole dist. out.

David

 

[TexasBronco]

Would using different weights of oil affect pressure at all? I have a 351C with a HV pump and (according the 30 year old gauge) it puts out well over 80psi and I already destroyed one cam gear, but I think it was a poorly cut cam and dist was fine. But would using a lighter or heavier oil matter?

 

[JWMcCrary]

Not to hi-jack, just wondering. Like I stated before, I keep eating dist. gears. I have the Comp. Cams 4x4 extreme cam, I have talked to them and they said that its due to the 60 psi oil presure? The motor has 6500 miles on it and I was going to pull the dissy back out to check it shortly. I has chewed one up around 1500 miles and the next probably at 3500.

Any ideas?

David

I'm running the same type cam with an MSD dist. The dist. came with some assembly lube for the gear. It warned if not used the gear could possibly get damaged.

 

[blubuckaroo]

My stock 302 runs 80 psi with 10W-40 oil. The motor had over 200K on it before rebuild and still hat over 70 psi!
It seems I've read about an issue with the dist gear. Some came with bronze and some with steel. They can't be inerchanged! Maybe someone else can help with the reason.

 

[Broncobowsher]

Would using different weights of oil affect pressure at all? I have a 351C with a HV pump and (according the 30 year old gauge) it puts out well over 80psi and I already destroyed one cam gear, but I think it was a poorly cut cam and dist was fine. But would using a lighter or heavier oil matter?

Yes, different wieght oils do affect oil pressure. thick oil (high numbers) doesn't flow as well, so the pump has to work harder and at higher pressures to push the oil through. My method of determining oil weight for an engine is to run the lightest oil possible without getting into hot low oil pressure.

As for the distributer gears, there are 4 kinds.
Cast for flat tappet cams only.
Steel for roller only.
Bronze with work with either, but is known for wear.
Polymer, new, it will be a few years before I consider the durability of these. But are suppose to be compatable with either cam and last longer then bronze.