Anyone have a log showing oil pressure at 6500 rpm on a ZL1 LT4? Doesn't matter on mods or tuning. Just need to see oil pressure. I am seeing a spike in oil pressure from 65 psi to 85 psi starting at 5900 rpm on a cammed ZL1.
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Anyone have a log showing oil pressure at 6500 rpm on a ZL1 LT4? Doesn't matter on mods or tuning. Just need to see oil pressure. I am seeing a spike in oil pressure from 65 psi to 85 psi starting at 5900 rpm on a cammed ZL1.
Anyone?
I don't have a ZL1 but a Corvette. But the only time I had the oil pressure spike like that on a WOT pull was when I had a front main seal leak during the pull. Even after the pull was over and idling, the oil pressure stay around 10 psi higher.Quote:
Originally Posted by 32vape
Mine shows 50psi until 6k then it goes to 60.
That's typically what I see. We rebuilt the engine on this one. New GM oil pump, bearings, rings, Johnson 2110 lifters, deleted vvt, deleted dod, cam, Manley LT4 spring kit, Trend pushrods .060" lifter preload cold. Done several just like this with all the same parts and never had this issue. Never had this much oil pressure though. Right where the oil pressure spikes I get a big drop in power. It gets better with hotter oil temps. Don't see it being a tuning issue. The guys at Johnson lifters said such an abrupt spike in oil pressure could upset the valvetrain.Quote:
Originally Posted by ZincGT
Red plot is hotter oil temp
Attachment 101174
Hotter oil temp log
Attachment 101177
Cooler oil temp log
Attachment 101178
Had a stock A10 LT1 camaro on the dyno this morning doing the same thing.... oil pressure would spike and it would loose power. Played with cam timing, injection timing, spark advance. Nothing obviously wrong in the log, airflow stays on track, throttle open, timing stays the same. 6k every time oil pressure goes to 80 power falls off.
These engines have a solenoid that allows for two different stages of oil pressure - have you checked whether this solenoid is being activated when the oil pressure jumps?
So the solenoid is normally energized below 6000 rpm. Above that it's released and the oil pump moves to the high pressure setting. I jumped the wire the ecu grounds to a permanent ground to hold it in low pressure mode all the way through the pull. No change in the dyno graph. Pressure never went over 65. I then switched out the valve springs for stiffer duals, still no change. I even got my camera setup with a timing light to video the balancer just to make sure the actual ignition timing matched what I'm seeing in the scanner. Really starting to pull my hair out on this one. I'm going to try plugs, wires and coils next.
Your ever fix this? Just checking back.Quote:
Originally Posted by 32vape