Ok im sure that people will tell me to search old threads but.. the search isnt up yet so i need to ask. what is the compression supposed to be for a 2.8. its from an 89, i would say close to 80,000 miles on it. ive been tryint to test everything on this motor before i decide to trash it and start with a fresh block. thanks for the help.... its greatly needed.

 

well compression ratio is 9:1, but if your talking about measured PSI from a compression test i dont know exactly what you should be reading. it depends on altitude, humidity and temperature too.

 

so there is no real way for anyone to tell me?? <---- im just asking , not trying to sound rude. I live in houston Texas, its been pretty hot here recently. i would just hate to throw this motor away if i didnt have to.... i mean i have another one ready i just dont want to switch it out in this rx-7 if it wasnt needed.

 

Anything over 160 is good. Make sure all the cylinders have simliar pressure.

 

great, thanks ... im going to check the compression after this weekend....... *** i hate work. but thanks alot. it helps alot being able to ask questions.

 

its not so much what it should be, al ur cyl's should be withing a certian percentage of each other, dont forget to wedge the thorttle wide open when u do the test, or u wont get a right reading

 

Pull the coil wire, too.

ALL 6 cylinders should be within 10-15% of each other.

Mainly, cam will affect your dynamic compression when doing a compression test. I come out at 155 across the board (except the 2 busted piston cylinders ) and that was fine.

Yes, make sure you hold the throttle down when you do it.

 

You know what I do? I pull both connectors off the distributor, that way you don't fire the injectors either.