FC3S Murray's never ending build.

NoDOHC · 09-14-2009, 10:40 PM

I used a piston compression tester, I got 115 psi pulses on all faces at 5000 miles. (I got about 100 at 500 miles). Total compression (check valve in) was a tick over 120 on both rotors. I think the piston tester works just fine, I don't understand your low readings.

By chance, did you try dumping oil down the spark plug hole and trying compression test again? (you should gain ~5-10 psi) If you gain a lot more, I guess more break-in is in order.

I premixed for the first 200 miles and then quit mixing after that until 5,000 miles, when I started mixing again.

09-14-2009, 10:40 PM	#11
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	I used a piston compression tester, I got 115 psi pulses on all faces at 5000 miles. (I got about 100 at 500 miles). Total compression (check valve in) was a tick over 120 on both rotors. I think the piston tester works just fine, I don't understand your low readings. By chance, did you try dumping oil down the spark plug hole and trying compression test again? (you should gain ~5-10 psi) If you gain a lot more, I guess more break-in is in order. I premixed for the first 200 miles and then quit mixing after that until 5,000 miles, when I started mixing again. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)