hi im in need of a bit of help, can any one tell me what are the best compression readings for a 1994 13b turbo engine, still standard, iv had a good search on the web but not had a clear answer,

Best regards Guy

 

On page 1-11 of my Mazda service manual (it's for 1988, but it would still apply) there are two graphs. One for compression pressure vs. cranking speed, and another for altitude compensation. Compression should be 85 psi at 250 rpm, with not more than 21 psi difference between chambers.



In my experience, healthy engines show numbers around 90 psi on a conventional compression gauge with the valve core removed and a healthy battery turning the engine over.



Hope this helps!

 

For my '94 rx7 I bought a rotary engine compression tester. @ 250 rpm for the three chambers, I'm getting 110, 106, 106 psi avg. for front rotor and 104, 103, 104 psi avg for rear rotor Car has 43k miles and never been rebuilt.

 

From what i've been told 110psi is the mark your aiming for. Thats what i was told by the people who rebuilt my engine.