So I’ve been looking at different RX-8s, and found an S1 that the owner claims has a rebuilt motor with less than 3.5k miles on it. However, I’ve called all Mazda dealerships and workshops in my country and none of them have the rotor engine compressor, and claim that a standard test would be fine, and that I should expect a value of around 90 psi if the engine is indeed freshly rebuilt.

I read here that a rotor engine compression test is a must but the equipment sadly isn’t available here. Can I at least get a vague representation of the status of the engine with that single psi value or is that test completely useless? Thanks!

 

Personally no you cannot use a regular compression tester.

But why don't you decide.
Start reading here, it isn't long nor that technical.
I'm sure you'll come to the same conclusion.
https://www.rx8club.com/new-member-f...2/#post4533733

 

It can be tested with a regular tester but it won't be as accurate but will get you close. When you perform the test, you are looking at not only PSI but RPM as well. The number has to be adjusted to 250 RPM. You should get 3 readings, one for each rotor face per rotor. There is only one video I've seen that accurately shows how to perform a test with a regular tester by Drivenbymadness:

 

Thanks for the info, I’ll check it out

 

Let's us know how you make out please