i have a fully built z6. wiseco 9.1 compression pistons and the motor has about 3,500 miles on the motor. well the car was fast for a while and it seems much slower to me know. i have no idea why, so i did a compression check. i got 160 in 3 cylinders and 165 on the last one. does that seem low? i mean the motor only has a few thousand miles on it. should i be in atleast the 200's?

 

I beleive 185 is the number that you are looking for. Are you sure you did the compression check correctly?

 

you didnt beat on it at all did u??? when you rebuild a motor and start driving it around you need the rings to set... it honestly takes about 5-7000 miles for them to be set to where you can beat on it.. but it takes around 20 thousand miles for them to fully set....

you didnt use synthetic oil at all did u??? synthetic oil is too slick and it wont allow the rings to seat eaither...

keep driving it slow.. dont take it over 4 thousand...if you want to break it in faster... when ur on the freeway.. dont hold a constant speed.. go from 60-90-60-90-60-90... thats how i broke in my motor in my coupe 4 years ago when i rebuilt my z6 and when i hit the 15 thousand mile mark i got on it and oh **** that thing pulled sooo ******* hard.. i know the freeway thing will get anoying.. but it helps from the rings seating at a certain rpm...

its not good on a new rebuilt motor or new motor to hold a constant rpm at all anyway... you either want to be speeding up slowly or slowing down

 

also make shure your motor is warm when u do the compression test. and keep spinning the motor over until the guage stops.. it should only be like 4-5 revolutions...

 

no, i didn't use synthetic oil. i just used regular oil no synthetic