Forum > Hybrid/Tech
Compression test results help?
Eggylshatch:
Engine is a b20z, so I think it should be the higher CR engine if its stock internals, 9.6:1 I believe. Bought it used from another guy years ago, supposedly a low-mileage JDM engine, but have no idear. I did a compression test just to check on the health because I'm planning to boost it.
Results:
4 3 2 1
151 150 150 151
I tried putting a bit of oil down #1 and it bumped it to around 161. I tried two different compression testers. if it was shitty ring seal, wouldn't the oil bump the pressure higher? It doesn't seem likely to me that the numbers would all be so close if the engine was beat to hell enough for the pressures to be this low?
Am I doing something wrong? My battery is a little weak so the engine cranks more slowly maybe, but I let it go 12 cranks for each cylinder. I watched the gauge for about 10 sec each time, didn't seem to be losing pressure. Could there be lower CR pistons in there? Or is this just a saggy old bitch of an engine?
Tim:
seems real even to be beat.
did you hold the throttle open?
Eggylshatch:
--- Quote from: Tim on May 17, 2017, 03:12:59 PM ---seems real even to be beat.
did you hold the throttle open?
--- End quote ---
That's what I thought too.
I did hold the throttle open for the first test for sure, I might have forgotten to do so when I did it with the second comp. tester. I used mine first which looks a little rusty and beaten up from years of riding in the bottom of the tool box so I was a little skeptical. The second one I grabbed a rental from o'reilly auto parts. Maybe I should rent it again and make sure I didn't screw it up that time... Weird to get the same results for both though.
ratcityrex:
Cam timing? It's real even. If your rings were sloppy the oil would have bumped the comp up a bunch more there 10psi. I'm thinking the cam timing is funky. Off a tooth or something on the belt.
Eggylshatch:
--- Quote from: ratcityrex on May 18, 2017, 01:53:37 AM ---Cam timing? It's real even. If your rings were sloppy the oil would have bumped the comp up a bunch more there 10psi. I'm thinking the cam timing is funky. Off a tooth or something on the belt.
--- End quote ---
Hmm. I'll see if I can double check it. I had a cluster when I put it back together- it has adjustable cam gears on it and a crankshaft pulley off a b18a and it's missing the lower timing cover with the handy mark on it. So something could certainly be off
Navigation
[0] Message Index
[#] Next page