goose415

i just did a compression check on my FC. 90psi with the front and 98psi with the rear..... what are good compression readings?

RotaryRocket88

iTrader: (7)

100+ psi would be be "good" numbers. 90s are ok. The specs listed in the FSM are something like 85 psi minimum, but obviously higher is better. Also be sure the throttle is open and the tester hose isn't too long, as these factors can change the numbers slightly.

Kerberos_8

iTrader: (2)

those are good it also depends on your year as s4 rx7s have lower compression rotors then s5. I believe 75 psi is like minimum and i have seen them run with like 60 psi. 90+ i would say is good and 100+ is like a rebuilt motor

goose415

its an 87 GTU and it smokes alot but put those compression numbers up.

Kerberos_8

iTrader: (2)

rotary engines dont smoke because of low compression like piston motors do. If it smokes alot its either because its leaking coolant and burning it or the oil control rings are worn out. If the oil control rings are worn out i wouldn't worry about it till it smokes so bad its unbearable. If its the coolant seals you would have to rebuild the motor

goose415

oh... im a newbie to the rotary scene. thanx for the help.... but are those numbers good? it has 190000 miles on it.

TwistedRotors

iTrader: (3)

Those numbers are good.

schoolinz

bump