Oil pressure fresh engine
11-22-2015, 11:40 AM
#1
Oil pressure fresh engine So, I'm a junkyard guy and have always thrown together salvaged engines and shimmed the stock oil pump with success.
My first time I ever get a fresh short block, I had a spare 6 liter LQ4 get bored out .020, reconditioned rods and cut crank, balanced the assy.
I get it home, throw the heads on, a GM hotcam, a brand new melling stock replacement pump and swap it in to my 3/4 ton.
Was 40 PSI when I started it and now after some tuning and driving it is down to 30 give or take even on cold starts.
My 2002 SS Camaro with 150k miles holds 40 PSI after I beat the **** out of it so I was curious how many of you may have had the same pressure drop new.
It doesn't bother me since I've beat it a little and have maybe 100 miles on the new engine and the one noise is the used lifters making the typical sewing machine noise.
Using a mechanical gauge by the way.
My first time I ever get a fresh short block, I had a spare 6 liter LQ4 get bored out .020, reconditioned rods and cut crank, balanced the assy.
I get it home, throw the heads on, a GM hotcam, a brand new melling stock replacement pump and swap it in to my 3/4 ton.
Was 40 PSI when I started it and now after some tuning and driving it is down to 30 give or take even on cold starts.
My 2002 SS Camaro with 150k miles holds 40 PSI after I beat the **** out of it so I was curious how many of you may have had the same pressure drop new.
It doesn't bother me since I've beat it a little and have maybe 100 miles on the new engine and the one noise is the used lifters making the typical sewing machine noise.
Using a mechanical gauge by the way.
11-22-2015, 07:34 PM
#5
Forgot I have a minor intake sealing problem and I got it to where it's not very bad but was causing bank one to dump fuel trying to compensate. Just checked oil and I smell fuel. So that should be it. Just diluted the oil. Was so bad the truck didn't want to idle till my buddy did a initial tune.
11-23-2015, 05:47 AM
#7
Think you found your issue, however it should be noted that most refresh engines end up with slightly larger bearing clearances than the original GM product. Their design parameters are 250,000 miles whereas we just want a **** ton of power RFN (right ******* now)
Lastly did you not port/shim the pump in this particular build ??? I'd consider doing that as it only helps the bearings/ lifters/etc.
Lastly did you not port/shim the pump in this particular build ??? I'd consider doing that as it only helps the bearings/ lifters/etc.