80 PSI Oil pressure

[71GTX440]

I have a stock 440 on a 727 trans. Read on other FBBO post that running Rotella 15W40 oil and adding 4 oz. ZDDP will not hurt the engine and will hep. I now have 80+ psi on start up with cold engine. With a warm engine (195 degree), idling at 75 psi. Accelerate, i run 90+ psi for oil pressure. Did i miss something? 90+ psi seems outside of any safe range for this engine. Should i drain out and run some 10W30/40 perhaps.

 

[HawkRod]

I'm no expert, but why run 15W40 oil? In my opinion, the only reason to run that is if your engine needs a rebuild and has low oil pressure. The thick oil helps in those cases. In all other cases, thick oil is going to hurt you. It will take longer to get where it needs on startup, and will not flow as well through the engine.

 

[71GTX440]

Engine isnt leaking and runs good. Read on other posts, due to displacement in these engines; running a thinner viscosity oil is worthless. Going with a higher visvoty oil is beneficial and preferred. Looked deeper on bobistheoilguy.com website that 15/40 is safe as well. I am worried the higher oil pressure will cause unnecessary pressure and cause leaks or worse.

 

[terzmo]

I have run 20/50 in all my 440's....80 at start....65 to 70 when warm..old iron...likes heavy oil

 

[Nacho-RT74]

I'd never think on use less than 20/50 on my car

 

[Dennis H]

My funky factory gauge is mostly pegged. Who knows how accurate it is. 10/40 Amsoil per my builder.

 

[Mr Belvedere 30144]

I also run VR1 20/50 My pressure runs about 40 at idle hot 50 cold. 60 on the road on average

 

[HT413]

Btw, no need to add zddp to rotella T triple protection, study's on bobs site show it has the necessary zinc.

I run it in my 413 and my pressures are about 75 on cold startup and up to about 80 warm at acceleration and in the 40's warm idle.

I don't think leaks are possible due to slightly high pressures, there are no seals that see pressure that I'm aware of. The only issue is robbing some horsepower. Do you have a high pressure pump or did someone modify the spring in the oem pump for higher pressure?

 

[71GTX440]

From what i have found, everything is still stock. No upgrades of any kind less the intake and carb.
Rotella didnt need the zddp additive up until a few years ago bwhen the EPA cut the allowable zinc levels in diesel oils. Rotella 15/40 does need the additive.

So i shouldnt worry about the high psi? Not worried about robbing HP as i go to cruise ins and car shows primarily. Not doing any racing unless some young kid in a honda with coffee can exhaust feels froggy at the stop light

 

[RedHot67]

Go for 10W-40 with enough zinc (Brad Penn for instance, or Lucas hot rod oil).

 

[HT413]

Rotella didnt need the zddp additive up until a few years ago bwhen the EPA cut the allowable zinc levels in diesel oils. Rotella 15/40 does need the additive.

According to joe Gibbs racing oil's website, that occurred in 2007 and did not affect high viscosity oils like 15-40 rotla triple.

 

[monaco66coupe]

I use Rotella T with Lucas in all my cars. They all pull 50-80 PSI pressure. I had an oil leak when I used 10-30, conventional oil, and it quit when I Went to Rotella. The diesel oils protect the engine parts better, and don't have that quick drain down feature new oils have for the new cars.(fuel mileage Increase supposedly) The new oil also don't protect anything once the engine is shut off. The Dry start I heard all the time is now gone when I went to A diesel oil, and 15-40 is good for old mopar engines. In the 60's most everybody used straight 30W in the summer, so going to 40W is a negligible difference. 15W in winter with lubricating properties beats 10w with no viscosity features any day.

 

[HT413]

Back to the show though, 80 psi at idle is pretty high. No I don't know that it is a problem per se, but strange that it doesn't modulate with rpm. What make gauge do you have? Perhaps it's worth confirming with another gauge?

 

[monaco66coupe]

Looking at the gauge is a good idea, but if the engine is fresh, I would give it some time, put on some miles. My 68' Service manual for the 383-440 shows 45-65 lbs @1,000 rpm. The engine oil weight was 10-30 when sold new. If your engine was built really tight, then the pressure can be higher. I have one 440HP with 75lbs warmed up(done in 2003) and a 383 with 40 hot and 75 cruising at 65-70. I'm not worried about either. The same builder did both engines.

 

[71GTX440]

Engine is not fresh. Planning a rebuild this winter. Pressure finally evened out. Have 80 - 90 psi on cold engine start, 60 - 70 psi on warmed up engine. Engine seems to have better response and has quieted down as well.

 

[monaco66coupe]

Better a little high than a little low, I always say! Now 20psi, I would be worried.

 

[am3rican]

Better a little high than a little low, I always say! Now 20psi, I would be worried.

Mine runs 14-20 psi at hot idle. I use 20w50 Brad Penn. Not a worn motor but a fresh motor, rebuild maybe 4K miles ago. Any ideas whether this is normal and I shuood be worried?

 

[coloradodave]

As long as the pressure increases with the RPM, it's not a problem. Generally just indicates bearing clearances that are a little on the loose side. If it makes you feel better, you can always shim the oil pump spring or buy one that's a little longer.

 

[monaco66coupe]

I was referring as a comparison to 55-75 lbs. In reality the oil pressure light on a brand new 1969 engine is set to go on at 7 psi. So, apparently Chrysler thought anything above that was safe. As the above post said, if it goes up as you go, keep going! I found that cranks and rods with loose clearances have lower oil pressure. So there is a lot of variance. Older Mopars were running 25-45 in the 50's. So I wouldn't worry too much. My old 41' ran 20 lbs all the time, and things worked very well.


What I meant was if you are pulling 20 lbs driving, not at Idle. I had a 68' 318 that pulled 15-18 at idle, and 40 going 70 mph. It would run forever in that scenario.