wirelesswally

I performed a compression test today as discribed (remove both Leading plugs, crank the engin with pressure reliefe valve depressed then crank with the pressure reliefe valve closed) the directions stated that with the gauge pressure relife valve open You should see it in the 30-35psi range. with the relife valve closed a pressure of 115+ is like new 100-115 = healthe 90-100=weak. On my tests the front rotor with the relife valve open my reading was 75psi and in the closed position was 135psi. The rear rotor was open=90psi and the relief valve closed was 145psi. This differs from what the numbers called for on the valve open position of 30-35psi. What are your thoughts reguarding pressures of this nature. Wally 1979 1st gen rx7

RotaryRocket88

iTrader: (7)

You're going by this guide, right? http://www.rotaryresurrection.com/2n...ion_check.html

It fails to mention one very important thing. You MUST remove the schraeder valve from the tester prior to performing your check. Schraeder valve springs are not all created equal, and this will interfere with your numbers.

Crank the engine while holding the relief valve, and watch the pulses. Minimum factory spec is about 83 psi, but this is really the bare minimum. Ideally, you want 100+ psi.

You can leave the relief valve closed to measure "total pressure", but that really will just show you the highest pulse of the 3.

Also keep in mind that gauges do require calibration. If you're using an old gauge, there's no way to know if the readings are off.

wirelesswally

Rotaryrocket88, I reperform a new compression test as your message stated and here are the results Rotor 1 = open valve on compression test was 90psi and closed was 120psi. Rotor 2 = open valve = 85 and the closed valve read 110. The tester is brand new and I was wondering what you thought these readings might indicate. BTW the schrader valve was removed for for all testing. I thank you for your help and advice Wally

RotaryRocket88

iTrader: (7)

If the pulses with the valve open are an even 85-90 psi, that indicates an engine that's nearing the end of its life. What's odd is that you were able to see higher values with the valve closed. That normally just shows the highest of the 3 pulses. If pressure is building, there must be a check valve in the gauge or something. The pulses with the valve open are what matter.