Acceptable compression #s
09-03-17, 01:43 PM
#1
Acceptable compression #s
Just delivered my FD to my tuner after installing my new Turblown 8374 kit to tie up some loose ends, correct any improper installations, basically wrap up my build and put a tune on the car. Car starts ok cold or hot, runs good, but idles rough and has a slight stumble until it gets to about 65-70c indicated on the pfc commander. Car sat for about 1 year while waiting on the turbo kit but now has fresh fuel and premix. Compression test showed mid-90s to 100s on the rear rotor, front showed 85-75-85. Thoughts?
09-03-17, 03:17 PM
#4
https://www.rx7club.com/general-rota...-motor-858218/
Post 6, banzai racing gives some good useable info. Bad/stuck side seal is usually more than 10 psi difference, no?
Post 6, banzai racing gives some good useable info. Bad/stuck side seal is usually more than 10 psi difference, no?
09-12-17, 08:01 AM
#7
Either it's stuck, or it's damaged. Your compression results (85-75-85) may give you a hint on which it might be (stuck or damaged), but I'm not sure. If it were simply worn, you'd see similar (lower) numbers with the other rotor. I'd try the easy/cheap route first and go from there.
Last edited by TomU; 09-12-17 at 08:04 AM.
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09-12-17, 09:48 AM
#8
Tuner has already pulled the motor ahead of schedule. Motor was torn down this morning. Broken corner seal and slightly damaged rotor. Damn. Motor ended up having 3mm apex seals. He said that probably partly accounted for the lower compression numbers.