low compression
Read post #8
Ok so did a leakdown test and results were good. Being confused as hell we did another compression test and was now better than last time, Actually it was pretty good. Wtf is going on? We’re thinking a lifter maybe? If a lifter is not functioning correctly can it be causing mixed results like this? I know a bad ring will not change results. It’s obviously something in the head. I’m thinking replace all lifters since there’s a hella lifter tick anyway and getting better cams with springs and retainers. I’ve heard mixed reviews about gsc zero tick. Map told me to buy itm lifters which is an oem revised lifter. What do you guys think? Also thinking gsc s2 cama and get rid of the bc cams. What do you guys recommend for springs and retainers? Was thinking kiggly? But damn those sob are expensive.
If youre getting good compressions from cylinders 1, 3, and 4, these 12 lifters should be good. If you're taking off the valve cover, press on all to make sure they don't compress. My guess is at least one of cylinder 2 lifter is leaking. Hopefully, it's that simple where you buy 1 replacement. I believe GSC cams will make a bit more power, but is it worth the money? As for replacing valve springs & retainers, that's a lot more work. Whose vales and retainers are in the car now?
Ok so did a leakdown test and results were good. Being confused as hell we did another compression test and was now better than last time, Actually it was pretty good. Wtf is going on? We’re thinking a lifter maybe? If a lifter is not functioning correctly can it be causing mixed results like this? I know a bad ring will not change results. It’s obviously something in the head. I’m thinking replace all lifters since there’s a hella lifter tick anyway and getting better cams with springs and retainers. I’ve heard mixed reviews about gsc zero tick. Map told me to buy itm lifters which is an oem revised lifter. What do you guys think? Also thinking gsc s2 cama and get rid of the bc cams. What do you guys recommend for springs and retainers? Was thinking kiggly? But damn those sob are expensive.
Now I believe it has stock valve springs and retainers. I’m thinking just replace all lifters. Prob going with itm. I would go gsc since I’ve never heard of itm but have read too many posts where people say they had issue with these. There’s was a thread where a dude received them different sizes. Wanted kiggly springs and retainers but I can get a deal on gsc. What do you guys think about gsc springs and retainers? Should be fine right?
That was me with different heights on my 5041 set. What matters is that the resting height has the right pressure. Of course, I couldn't measure that consistently to check. In a long run, I doubt it matters too much as long as it has enough pressure to keep valves from floating at 9000 rpm.
I think the bad batch was the 5039 or lower set that failed. I made 460 hp with my 5041 and had it tuned to 8000rpm.
I think the bad batch was the 5039 or lower set that failed. I made 460 hp with my 5041 and had it tuned to 8000rpm.
Now I believe it has stock valve springs and retainers. I’m thinking just replace all lifters. Prob going with itm. I would go gsc since I’ve never heard of itm but have read too many posts where people say they had issue with these. There’s was a thread where a dude received them different sizes. Wanted kiggly springs and retainers but I can get a deal on gsc. What do you guys think about gsc springs and retainers? Should be fine right?
yeah but theyre within 5 psi of each other...i got 3 cyl that are the same and one with 30 psi less...runs like a champ but obviously theres something going on...
My guess is once engine goes WOT, the lifters hold better since it is much quicker and doesn't give lifters enough time to compress much. Keep us posted on results. I really hope it is simply the lifters for your buddy.
I forgot to ask you to smell your buddy's oil cap. If piston rings are bad, I think gas gets into the oil and you can smell it. Same thing with catch can if he has one.
Last edited by 2006EvoIXer; Mar 6, 2018 at 01:08 PM.
Yeah oil smells a bit like fuel but if this was the case I would expect smoke/oil consumption which there is none. Also doesn’t feel like it lost any power.
Last edited by nor11384; Mar 6, 2018 at 01:08 PM.
Smoke would likely be valve stems leaking. Bad piston rings allow unburn gas/air to seep through during compression stroke. It allows even more burnt gas/air to seep through during power stroke. I don't see how oil enters combustion chamber through piston rings.
As for power, our butt dynos can't tell the difference between 350 whp and 325 whp.
If it can, I wouldn't trust it.
Maybe there's enough oil splashing around to seal the piston rings during WOT?
If it can, I wouldn't trust it.
Maybe there's enough oil splashing around to seal the piston rings during WOT?