VettePower

When I first start the Vette, it reads 40 to 45 lbs, but after a while of driving it once it is warmed up it drops to about 38lbs. The motor is a rebuilt L82, and does not seem to burn or lose a drop of oil. Is 38lbs pressure safe for the car. If not what do you think could be wrong? What oil pressures are yall running?? :confused:

Bobchad

40 pounds when the car is cold. After warming up, 20 pounds at idle and around 35 - 40 at cruising speeds.

Bob

page62

Original L-82 (see sig.): 60 lbs. cold and 40 lbs. hot. Very good pressure.

I think you're OK, though -- that's still plenty of pressure. I once had a car that would drop to zero at idle -- now that's a problem! :yesnod:

TedH

With High Volume Mellings Oil Pump:

65lbs at idle upon start-up
35-40lbs at idle once warm
65lbs at speed once warm

norvalwilhelm

This is in a bigblock with a high volume pump. 80 plus pounds cold, hot idle 50 pounds, low cruising 60 pounds and above 2800 cruising about 70 pounds.
I thought the rule was about 10 pounds per thousand rpm.

fauxrs

You dint have anything to worry about - you are well within acceptable ranges.

GrandSportC3

When the engine is cold - between 45 and 80 and between 25 (idle) and 45 when driving...

:cheers:

Olivier

Fevre

Guessing since you are in Texas your 'cold' is still pretty warm. :) I agree you are well with the correct range esp at warm idle.

Turbo-Jet

I just installed a new standard-volume pump, enhanced with some lapping and using the stiffer relief spring with 10W-40, and 1 litre of 50W.
cold start 60 psi
hot idle 15 psi
hot cruise 35-40 psi

My factory engine specs 40 psi @ 2000 rpm, I am a little on the low side still, but the engine has been rebuilt, and likely was made a little loose. Still very accetable.

Binnie77

Car has 70K miles and 10w40 Penzoil

Cold Start > 45 - 50 psi

Hot Cruise > 35 - 40

Hot Idle > 20 psi


[Modified by Binnie77, 1:44 PM 9/4/2002]

OHSIXX

Mine stays about 55 psi at 60 miles per hour, but it will not matter after next week when the new engine is ready. :)

Bobchad

Turbo,

What is involved with changing the oil pump and the relief spring. My car has some "twitching" of the oil pressure gauge between 20 and 40 psi on occasion. While I'm going to start out replacing the sending unit I may have to go here as well.

Bob

VettePower

Ya'll took a big worry off my shoulders!!! Thank you again Corvette Forum members!!! :cheers:

BeaterShark

I'm really suprised in the slight difference between cold and hot idle pressures. Heck, even at 100 degrees F, the viscosity of a 10w30 is around 70 cST and at 212 F (which should be close to hot) is down to the 10.5 cST range. I think there is something wrong with that reading.

Other than that, those numbers are fine.

Bobchad

Isn't that due to the oil pressure relief spring?


[Modified by Bobchad, 2:28 PM 9/4/2002]

Turbo-Jet

It is pretty easy to do. Some guys like to add some washers, to shim the relief spring to get a bit more pressure. But if you are already underneath with the oil pan off, I'd say just replace the whole pump. My pan came off easily; remove starter, bellhousing cover, filter, dipstick, and idler arm to drop steering linkage. Also, rotate crank so timing mark is at bottom (I think...), which allows for more clearance around the counterweights. Get a 1-pc Fel-pro pan gasket and a Melling or Federal-Mogul standard volume pump with a metal-coupling driveshaft. I took my new pump apart and lapped the machined faces to improve cover sealing, and to reduce the gear clearance to the minimum spec. Also use some non-hardening sealer on the pump-block joint. Setting the new pickup screen height is the trickiest part. Get it close by comparing with the old pump, then check and make final adjustments by temporarily installing and checking with clay.

Bobchad

Thanks Turbo. I'll likely be giving it a try sometime this Winter.

Bob

Paul L

"Readings of 30 to 40 psi may be considered normal during moderate road speeds of 35 to 40mph with the engine at proper operating temperature."

(1979 Owner's Manual)

You are bang on the specs.

loflite

I've got a '69 BB that is idling at about 45 psi and is pegged at max under any throttle. Anybody know if it is the pump or the sending unit. It does go to zero when shut off.

Scott78

Same pump, same numbers as Ted

Scott