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View Full Version : LS cranking oil pressure to prime?


jlwdvm
02-16-2016, 10:07 AM
I am getting ready to fire the new Texas Speed LS3 in my 69 firebird. I primed the motor as best I could through a pressurized tank I made and plumbed into the front Driver's oil galley. I ran 7 quarts through the motor twice and was able to get oil to 1 push rod on the passenger's side. I replaced the valve cover and removed the primer. With the computer and fuel pump disconnected, with a charged battery, I was able to generate 40psi at the oil filter location with a mechanical gauge. It took some cranking to get the pressure built up. Does this sound normal/ok? I'm using Joe Gibbs BR oil (what Texas Speed sent with the motor).

Ron in SoCal
02-16-2016, 03:26 PM
If it were me and I had primed it to 40 PSI, I'd fire it.

Che70velle
02-16-2016, 04:02 PM
I pre-oiled mine through the oil pressure sensor opening, at the rear of the engine. I wouldn't say I pressurized it, but i had oil coming out of the stand pipes, under the valley cover, like a small fountain. I wanted to make sure all my oil passages were at least wet. Installed the engine, and did as you are doing with the starter. I did however pull my spark plugs, to help the engine turn over easier, and relieve the load on my rod bearings, while cranking.
I'm running the Mast electronics, so I had my laptop connected to the car to watch the vitals. I turned the key, and my oil pressure went to 40psi in under 5 seconds. I put the plugs back in, made the necessary connections, and bumped the key. It fired off immediately, and had instant 50 psi oil pressure.

What you are doing is just fine...you probably have forged pistons, so you want to run the GOOD oil forever, btw.

EdyJun
02-19-2016, 02:15 PM
I would like to see oil on the rockers, I think 40 PSI is good enough.

Old66Tiger
04-07-2016, 07:55 AM
The factory throws oil in the engine, connects to a machine and spins until it sees oil pressure. What you did it's beyond any expectation for a LS engine

badazz81z28
04-07-2016, 04:05 PM
The factory throws oil in the engine, connects to a machine and spins until it sees oil pressure. What you did it's beyond any expectation for a LS engine

I think I read the minimum PSI for the LS engine is 10 per 1000 RPMS.

I would not sweat PSI by your non engine running. All you're doing is to have a goal of pre-lubing to prevent dry start. Once you fire it, its going to be in the 50s or greater.

waynieZ
04-07-2016, 08:18 PM
I would not sweat PSI by your non engine running. All you're doing is to have a goal of pre-lubing to prevent dry start. Once you fire it, its going to be in the 50s or greater.[/QUOTE]

Agreed


I was looking at my engine brakein instructions from GM for the LSA it says 6psi minimum at idle. I'd have a stroke if thats what I saw !

XLexusTech
07-16-2017, 11:19 AM
Hey sorry to rehash an old thread but today is a big day for me
First time cranking my gmpp ls3 does 25 psi cranking seem OK ?

dhutton
07-16-2017, 02:32 PM
Hey sorry to rehash an old thread but today is a big day for me
First time cranking my gmpp ls3 does 25 psi cranking seem OK ?

You are good to go.

Don

XLexusTech
07-16-2017, 03:01 PM
You are good to go.

Don

Thank you Don!

waynieZ
07-16-2017, 07:21 PM
I agree with Don, he's no rookie at this.