Crank case pressure
Crank case pressure I've been having issues with this new engine. Took it for a drive got into boost few pulls. Got home had done oil out the top of the dipstick and lots of oil and condensation in the catch can. Thinking I may have a issue with the piston rings. This engine only has free miles on it though. Any advice would be really appreciated.
It's possible you have bad rings, but how is your crankcase breathing? Catch can, stock PCV, vented to atmosphere, etc.? I've never owned a FI motor, so others that have will be better suited to answer, and more knowledgeable than I. Every engine absolutely must have some way to remove crankcase pressure. The LS engines, being of "Y" block construction are more needy in this department than the original SBC, at least where bay to bay is concerned. I'll say this much; I had an oil leak in my wet sump LS7 with LS1 oil pan. When I got it dyno tuned, my tuner/mechanic guy, who is VERY experienced, saw the mess under my C5. He asked if it was a seal, or gasket. I told him I thought it was the pan gasket. He said most every oil leak he has ever seen is usually due to poor crankcase ventilation. FWIW....
It has a catch can with 2 12 line coming out the valve covers. I ordered a compression tester for it. The engine is brand new only prob 10 miles on it if that. Hooping the rings aren't seated yet reason for the crank case pressure.
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The rings are not seated,,, depending on the ring choice thats a good 1500 to 5000 miles out.
You are running non synthetic for break in? Most synth oils wont allow enough friction to work the metals, rings, valve tips, bushing rockers..
Heat cycles are your friend on motors with AL heads during break-in.
You are running non synthetic for break in? Most synth oils wont allow enough friction to work the metals, rings, valve tips, bushing rockers..
Heat cycles are your friend on motors with AL heads during break-in.
I hardly ever drive the car much. I'm using Schaeffer's race oil. I was told it was fine. What oil would you recommend. I used roteta in my last turbo engine never had any issues
Last edited by transam001; Mar 15, 2023 at 06:14 PM.
Some engine builders use non-synthetic, non-detergent oil for break in. Many others recommend regular, non-synthetic oil to help seat the rings, and don't recommend synthetic until about 1,000 miles have been accrued. So I agree with the post about using plain motor oil until 1,000-1,500 miles minimum. 5w-30 should be fine. Use a lot of varying speeds to help seat the rings. Part throttle operation creates high vacuum in the combustion chamber, which helps draw oil up into the ring pack. This is one time that around town driving is probably a good thing for the engine.
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Do a leakdown and/or compression test to check the ring seal.
My turbo 4.8L has $50 Hastings rings and a dingle ball hone job and has no issues with crankcase pressure. Both valve covers have -10 lines to a vented catch can and that’s bone dry too.
My turbo 4.8L has $50 Hastings rings and a dingle ball hone job and has no issues with crankcase pressure. Both valve covers have -10 lines to a vented catch can and that’s bone dry too.
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From: Ohio
Don't think it takes much to seat rings
I compression checked my engine before running at 135 and after maybe 10 miles it was 155
That's just my experience, everything else I've heard says it should take longer
If the block was plateau honed it shouldn't need much if any time to seat. Just some load
I compression checked my engine before running at 135 and after maybe 10 miles it was 155
That's just my experience, everything else I've heard says it should take longer
If the block was plateau honed it shouldn't need much if any time to seat. Just some load
Ok I'll try that. It has a bigger turbo on it. Compression is suppose to be 12.9 to 1. What should the tester read when I compression be on the tester. Around 135 area? Sorry all the question. Thanks for all the help I appreciate it
Last edited by transam001; Mar 16, 2023 at 12:13 PM.
