Im having a problem with low compression when I installed jdm itr pistons w/ new oem rings in my gsr. compression as tested piston#1=180, #2=180, #3=210, #4=175. I first thought it was the rings(maybe i put them on wrong) so i took everything apart today and put eveything back together into freshly hone cylinders. Im still getting the same compression. and when I put a few squirts of oil into the cylinder to check compression again, there much higher in the 200's on all four. thats usually signs of bad rings. but the rings are new oem rings, and I doubt I put them on wrong. Gonna do a leak down test next week. any one else having this problem?

 

Its called a break-in period, rings take time to seat properly. Give it 1000 miles and try again. BTW, taking the rings out was a bad idea because any seating you previously started might prevent them from seating properly this time around. That or you have run out on your cylinders.

 

make sure your breaking into your motor right too...drive it hard but try and keep it away from high rpm's it'll help it seat better.

for example 1st gear full throttel to 4,000 rpm's 2nd full throttle 4,000k etc.

 

I see, I guess i shouldnt of taken the rings out, but after the break in period, the compression will increase? I forgot to mention the initial start up of the engine, there was some knocking, thought it was the timing. could that be it? or the low compression?

 

yes it should increase, but as far as knocking it shouldn't knock. Are you using atleast 91 octane?

 

alway use premium.

 

low compression needs 91 octane?

 

Since when is 11:1 "low compression?" BTW, knocking isnt good, that could be a slew of thing.....all are very bad.