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HangOver
11th February 2007, 11:57 PM
Hi All

I have an 81' v8 RR does anyone one know what the oil pressure gauge should read at idle?

I think mine has gone down since an oil/filter change but can't be sure.

streaky
12th February 2007, 01:28 AM
Obviously the condition of the crank, cam, rocker assembly and pump has the biggest infuence on oil pressure.
With cold oil you should be looking at 40psi at start up...dropping down slowly to 20-25.
With hot oil...about 15-20.

Then to complicate things...what oil? Synthetic will read lower than mineral across the entire rev range.

To get most accurate readings use a capilery guage for oil pressure taken off of one of the ports on the oil pump.
Not every one likes a capilery oil guages though...if you get it wrong you can puke out an entire sump behind the dashboard in less than five minutes!

HangOver
12th February 2007, 12:17 PM
Not every one likes a capilery oil guages though...if you get it wrong you can puke out an entire sump behind the dashboard in less than five minutes!

Does not sound like a good itea to me !

Im my old Rangie it's just got a round dial on the dash with a 1 - 4, (hmm maybe 5 ) gauge numbers, I was just wondering really if it falls below say 1.5 or something would this be a bad thing?

I know if it drops to 0 you probably need oil :D

Mine usually runs around the 2-ish, (or a touch higher) mark.

Ralf_the_RR
12th February 2007, 08:15 PM
The gauges go from 0 -4.
Which is 0 to 400kpa
Which is 0 60psi (ish)

Book says 210 to 280 kpa (30-40 psi) at 2400rpm.

Any oil pressure is better than none!

ladas
12th February 2007, 08:19 PM
The gauges go from 0 -4.
Which is 0 to 400kpa
Which is 0 60psi (ish)

Book says 210 to 280 kpa (30-40 psi) at 2400rpm.

Any oil pressure is better than none!

Sorry Ralf but wouldn't 0 be 0

Just the way my mind works ;)

justinc
12th February 2007, 08:32 PM
Rule number 1 with electric gauges, ESPECIALLY Lucas ones...Don't trust them.
Do a proper check with a decent mechanical guage to check. These electric gauges can over read with battery voltage fluctuations, I don't trust them at all. I look at the oil light before I trust the gauge.

JC

Bradtot
13th February 2007, 11:38 PM
Steve if your oil light dont Come on (providing light is working) then you have pressure.
As your motor wears things get worn meaning more slop/play bigger clearances where the oil under pressure can leak out which in turn means less pressure and this is made worse by hot oil which is thinner oil and leaks easier.
My oil light will flicker at Idle on a very hot day after working the motor hard and my Gauge reads almost zero. Rev it up at all is good.
At 343000kms this is what I would expect with a wornish motor.
As long as I dont leave it with the light flickering I am ok
I know a rebuild is coming soon
Brad:eek:

HangOver
14th February 2007, 12:53 AM
It's not that I was overly concerned, maybe it's because I used a different type of oil and filter this time, It's one of those purator filters or maybe it was over due a filter/oil change.
Maybe I just imagined it :)

I just thought that it should run in a specific range but by the sound of things as long as it's got oil in the sump and it's still running all is well