MY compression test results!

Post by **wild_maxx** » Wed Dec 14, 2005 4:55 pm

you always perform compression tests at WOT with the egine off..... so no air flow/ compression is lost or blocked.

Post by **Chezedik** » Wed Dec 14, 2005 5:52 pm

Comment withdrawn.
Modified by Chezedik at 10:34 AM 12/15/2005

Post by **nissanfanatic** » Wed Dec 14, 2005 6:13 pm

Nah... Just using the rings from the old piston works. They are properly worn to the wall to begin with.

Post by **sunnys14** » Thu Dec 15, 2005 11:05 am

i cant use the rings from the old piston if the current ring lands are blown.

Post by **AZhitman** » Thu Dec 15, 2005 11:08 am

wild_maxx wrote:you always perform compression tests at WOT with the egine off..... so no air flow/ compression is lost or blocked.

Hmmm.

IACV should let in sufficient air for a compression test.

Either way, good idea.

Post by **Chezedik** » Thu Dec 15, 2005 4:46 pm

I don't know if that is the case, check out this link:http://www.misterfixit.com/dyncompr.htmIt seems pretty important that the throttle be open.

Post by **nissanfanatic** » Thu Dec 15, 2005 6:24 pm

Quote »i cant use the rings from the old piston if the current ring lands are blown. [/quote]Why not? If they are not damaged, use them.

You MUST do compression testing at WOT. If not, then you are testing under vacuum. That would be about as accurate as testing under boost. Just don't do it. My car reads like 150psi if I don't test at WOT.

Post by **4felix20** » Fri Dec 16, 2005 5:00 am

i say tear that damn head off. i'm curious what happened...

Post by **Chezedik** » Fri Dec 16, 2005 6:05 am

fanatic, have you tested it that way, was that the result? I should think it would be much lower.

Post by **nissanfanatic** » Fri Dec 16, 2005 12:48 pm

I've tested both ways....

at WOT, I get 180 across all four.at FCT, I get 150 across all four.

Post by **Chezedik** » Fri Dec 16, 2005 8:27 pm

Huh, well then I have some things to look at.

Post by **PapaSmurf2k3** » Sat Dec 17, 2005 3:26 pm

why dont you just swap in the spare motor instead of pulling pistons and rods out of it, and putting them into the other one, worrying about if it will work, and honing it and stuff, just swap that whole thing in!

Post by **sunnys14** » Sat Dec 17, 2005 10:35 pm

too much work to pull the motor again. plus i just have the BARE block with pistons and rods. no oil pan, no nothing. im going to have to pull the head and replace the head gasket anyways so i might as well just do some extra work and drop the pan and undo the connect rod bolts.

Post by **nissanfanatic** » Sun Dec 18, 2005 1:23 pm

IDK... pulling the engine was like a 2 hour job for me... I'd much rather just swap an engine in than try to swap out a rod/piston with the engine in the car. Esp trying to angle-torque those connecting rod bolts from the bottom and not scratch the crank dropping the rod/piston combo in...

Post by **Warped** » Sun Dec 18, 2005 1:39 pm

also when doing a compression check have a jump box hooked up or a battery charger to get the same power out of the starter every time it turns over.and open the throttle blade to get full acess to air

Post by **Skidmark** » Tue Dec 20, 2005 3:21 pm

Take it off! Take it off! Ahem... the head I mean. You definitely need to do that before taking anything out of the bottom end. Check the head for warpage, and the gasket for leaks. With equally low compression all the way across, I very highly doubt your rings are the problem...

Post by **sunnys14** » Tue Dec 20, 2005 11:31 pm

but how would you explain the #4 cylinder spark plug filled with oil?

Post by **Craving4Boost** » Wed Dec 21, 2005 12:00 am

skid...i dont think you should HIGHLY doubt ringlands....is it the most common issue with ka-t's btw...

Post by **grosspolluter** » Wed Dec 21, 2005 9:19 am

Weak...............

Post by **GEO** » Wed Dec 21, 2005 11:25 am

compression check today after about 800 miles on the turbo without alot of boost time and even a boost spike to 15psi,

Before turbo:

195 , 195, 195, 185

TODAY:

195, 185, 195, 195

same compression gauge..

So I am still running strong

Post by **Structure240sx** » Wed Dec 21, 2005 1:13 pm

its that pintotech tunning im telling you

Post by **sunnys14** » Wed Dec 21, 2005 1:13 pm

lucky guy GEO... i hate you

Post by **Skidmark** » Wed Dec 21, 2005 1:51 pm

Craving4Boost wrote:skid...i dont think you should HIGHLY doubt ringlands....is it the most common issue with ka-t's btw...

I know it's common, but all 4 cylinders equally THAT low all at once? Unless we're looking at one helluva coincidence, my money still says that's not the problem. I could be wrong, trust me it's happened before But if it were me, I would pull the head first before doing anything else. Even if it turns out to be piston related, you've already got the head out of the way for removing the pistons. My $.02, take it or leave it...

Post by **GEO** » Wed Dec 21, 2005 3:13 pm

very true about the pintotech thing... How was the car you went up and checked out?

Post by **Craving4Boost** » Thu Dec 22, 2005 6:57 pm

sunny can get his car done he's just lazy and has to stop workin on his car at midnight...haha

Post by **Chezedik** » Thu Dec 22, 2005 7:30 pm

You all make the KA-t sound like a bad idea.... but F' it. I don't mind popping it. Say, what do you guys think about milling my pistons a little since I am rebuilding my motor. How much do you think I can remove from the pistons? Can I at least make my boost-world a little happier? (***-uming I keep my A/Fs and timing correct)

Post by **Chezedik** » Thu Dec 22, 2005 7:36 pm

Wow, I didn't think it would bleep out @ss.

Post by **sunnys14** » Fri Dec 23, 2005 1:01 am

dude... im super lazy.

Post by **Chezedik** » Fri Dec 23, 2005 10:50 am

I heart asian chicks.

Post by **sunnys14** » Fri Dec 23, 2005 4:35 pm

Chezedik wrote:I heart asian chicks.

what do you mean?

MY compression test results!

Re: (AZhitman)

Re: (wild_maxx)

Re: (sunnys14)

Re: (Skidmark)

Re: MY compression test results! (sunnys14)

Re: (Craving4Boost)

Re: (Chezedik)

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