I'm looking for used FD3S's in Japan but what i can't find is what the correct compression should be. People on this site talk about 90/125 but on the Japanese tests i see value's like 0.88KG/CM RX-7 ???R ????8.3 ???? ???(??)?????? | ????????????net?

 

US test is obviously on PSI while the JDM is in Metric.
You'll have to convert to whatever you are used to.
=The Mazda Rx7 Tester numbers like 8.3..not sure about that though.
I bought a TR-01 Rotary Engine Compression Tester engine compression tester which measures in PSI.

 

----> Metric conversion calculator, chart & table - online converter for US customary & metric system unit measurement conversions, plus currency converter & fractions to decimals

 

I figured it out compression is very good if its between 8.0 and 9.0. But sadly only like 10% of the dealers show the compression test when selling the car.

 

My understanding is that every 1.0 on the Mazda tester is like 14psi.
If you factor that in,9 would be 126PSI...sounds about right.

 

Thanks for the information, so 9 would be like new!

 

Ya 9 is real good.

I went to a rotary meet about the first year or so after getting my car and a guy had an actual Mazda tester.He did free Comp checks for anyone wanting one.
I said "for sure!!!".
My engine was hitting 8.4's and people were in awe!..why?.because the car looked like ****..lol!

Does the term: looks like ****" translate in Amsterdam?..also means looked liked poop,crap,Garbage,junk,rickety,beaten up,..plain old jalopy!...(Sorry I have to amuse myself somehow!)

 

Hahaha yeah i get it, and 8.4 is really good especially if you got a USDM FD. Because most of the FD's i have been checking are 99+ and even among these much younger spec's its hard to find good compression numbers.

 

Not to get off the beaten track of the topic but it was an FC..and N/A at that.

It would be nice for dealers to have a documented Compression test of the engine but half of them done;t even know what that thing IS or does under the hood.!

(looks like a Keg of Beer there,Leroy...where do ya tap it to get the suds?)