Compression low?
sganc4life_4
02-10-2006, 07:07 PM
120 110 110 110
thats my compression, its pretty even but I thought it was supposed to be at like 170-180?
thats my compression, its pretty even but I thought it was supposed to be at like 170-180?
E-Klips
02-10-2006, 07:22 PM
Yes that is low. Do a wet test and see if the compression raises. Dump a cap full of oil down each cylinder and recheck your compression.
2g compression:
178psi is standard
133psi is the service limit
2g compression:
178psi is standard
133psi is the service limit
ez1286
02-10-2006, 07:36 PM
:iamwithst If it goes up it means you're rings are worn if it stays the same (or really close) it's either valve seats, head gasket, or warped head.
sganc4life_4
02-10-2006, 08:10 PM
Well I did a wet compression test too and the results were:
120 115 110 110
120 115 110 110
95_GSX
02-10-2006, 08:30 PM
Well it just might be time for a rebuild.;)
But either way it looks like your pulling a head to see whats wrong.
But either way it looks like your pulling a head to see whats wrong.
ez1286
02-10-2006, 08:58 PM
Yeah, you're gonna need to do something soon, does the car still run?
sganc4life_4
02-10-2006, 09:03 PM
It will run once I replace the crank position sensor.
ez1286
02-10-2006, 09:19 PM
The compression in my talon was about that bad and it wouldn't run for shit. I think mine ranged from 95 to 140 though, and such a huge variance is worse than all of them being low.
scottsee
02-10-2006, 10:23 PM
Wet tests are not effective on flat-top pistons. They are good to do on dome style pistons only. On flat-top pistons the oil just puddles giving a false higer reading becasue of the extra volume.
crunchymilk55
02-12-2006, 02:04 AM
yep if those readings are accurat, it's rebuild time
sganc4life_4
02-12-2006, 07:35 AM
Well, I have a lot on my plate right now, including an 8 hour drive to FL in the middle of march, would I be better off buying a new engine and just dropping it in and rebuilding a monster out of my old one, or just rebuild it?
sganc4life_4
02-12-2006, 02:26 PM
Or can i just take a built bottem end and a head from SBR and use my cams to build everything?
gthompson97
02-12-2006, 08:23 PM
it all depends on what your goals are for the car. if you want a monster, you'll need to build it up but you'll need more than just a built bottom end and a sbr head, you'll need gauges and loggers and what not. the quickest way to get it running is to get a different motor (used or new) and just swap them out. the cheapest route will be to re-build it yourself if you know how but it will take more time than just a complete swap. your car, your decision.
sganc4life_4
02-12-2006, 09:01 PM
Well, im thinking about ordering the stage 1 long block for now, then having my motor on the side slowly building it. Do I absolutely need the 2g conversion for it, its another 1400$
ez1286
02-12-2006, 09:55 PM
Wet tests are not effective on flat-top pistons. They are good to do on dome style pistons only. On flat-top pistons the oil just puddles giving a false higer reading becasue of the extra volume.
Thats not really true considering the pistons are moving throwing the oil all over and coating the cylinder walls then getting to the rings.
Thats not really true considering the pistons are moving throwing the oil all over and coating the cylinder walls then getting to the rings.
gthompson97
02-13-2006, 01:59 AM
the are effective, but not anything close to as effective as dome-style pistons. scottsee is right though, all the oil pretty much does is take up volume, that's why you'll see higher results.
Automotive Network, Inc., Copyright ©2026
