How much Oil Pressure is too much?

[grubby65]

I have a 1964 Dodge Polara with the 383 and a leaking rear main seal. I have replaced the seal once and it still leaks (lip seal). My question is how much oil pressure is too much. The car is 99% street driven with an occasional romp on the throttle, shifting at 5000 rpm. The car was basically done when I bought it so I don't know a lot about what is inside the engine. It seems to have a rather mild cam. When using 91 octane fuel I can run 41 degrees total advance without any pinging. When I start the car up at idle it will run around 85 psi of oil pressure. After it is warmed up (195 degrees) it will run 65 psi at 2900 rpm (it has 4.10 gears). At idle when warm it runs around 35 psi. I am using 10W-40 Castrol GTX oil. I'm trying to decide if I should drop down to 10W-30 Oil, rebuild the oil pump with a lighter spring, or just live with the leak. When I say it leaks, after driving it and parking it in the shop, it leaves a puddle of oil on the floor about 4" in diameter the next day.

 

[62MAX]

The engine in my Superbird was done in 1992,runs around 85 lb at 2800 rpm,about 60 lb at idle,Brad Penn 20/50,has never leaked a drop.A 4" puddle is significant,oil weight and pump changes aren't going to correct it .

 

[lewtot184]

i wouldn't run that much pressure. it just tears other parts up. try changing the high pressure relief spring for a stock pressure spring first.

 

[WP29440SE]

I run 85 cold and 65 to 70 hot all day long with zero leaks. I wouldnt have it any other way

 

[69Bee]

I will almost guarantee that your leak is coming from the rear main seal carrier "side seals". Since Fel-Pro has decided to remove the CORRECT side seals that went in easily, and swelled after being soaked in mineral spirits, we have had tons of leak problems.

On the other hand, 80 psi cold/60 psi hot is just fine. If you don't like it, just remove the black spring, and replace it with the stock (natural, white, or yellow) spring.

 

[moparstuart]

I run 85 cold and 65 to 70 hot all day long with zero leaks. I wouldnt have it any other way

me i agree

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I run 85 cold and 65 to 70 hot all day long with zero leaks. I wouldnt have it any other way

me to i agree

 

[dvw]

The lower you can get your cold numbers the better. But not by changing the pump. Thinner oil is the key. Since multi weight oils can be 0W30 or 5W30. I would try 0W30. Nothing the matter with the 35/65 hot. However engine start up is the most critical wear time. If 30W hot keeps your hot pressure in the ballpark, use it. As far as your leak. The oil pressure is not the cause. My bet is the main seal bridge is not centered over the crank. If you have the crank out it's easy to see. I allow the bridge to center itself while tightening the bolts, do not use the side seals. Fill the side seal grooves with RTV. I have not had any leaks this way. For what its worth my 572", 15-1, 7200 rpm drag motor runs 0W30 Royal Purple, 30/65 psi. Just checked the bearings after 200 passes. They look like they came out of the box.
Doug