hey my name is Eric, i just bought a 1983 mazda RX-7 without an engine for next to nothing. everything is in just immaculate condition other then....well....no engine anyway ive seen a couple adds for engines on sale but im very new to these engines that i dont know what to look for when picking one up. i guess my question is, what should i be looking for when picking up a rotary engine? i was just at a guys house who owns 3 (2 of which are the 13b's and 1 12a) and i didnt know what to look for. they turned over which was good but what else would be something to look for in while looking at these engines?

 

Welcome aboard Eric, I am going to move this to a more appropriate section so you can get some more answers.

 

hi there!



there are a few things you want to look for in a used motor.



1. is it the right year and model? the 83-85 12A engines are the same, and would be a bolt in. 13B is a very easy swap.



2. the 83-85 12A engine is pretty easy to spot. on top of the aluminum rotor housings, it says 12A and mazda. on the rear iron housing, there is a heater hose connection, on the 83-85 motors it is a T for the weird oil cooler that is mounted on the rear iron. 84-85 engines have the engine wiring harness that goes to the US passenger side, instead of the 79-83 which goes the other way.



3. condition: hows it look? from the factory the engines are not painted, so the rotor housings are bare aluminum, and the irons are iron colored (they are actually coated with a nitride that is grey...). oil pan was black. if the engine is painted, its likely been rebuilt. also look for stamps, the mazda rebuilds had a stamp on the front rotor housing around the 12A area, usually its a date and initials, or after 96-97 they put a blue tag on the front cover.



you want to pull a couple of spark plugs and make sure it has compression, no compression = no run.

 

I say go with the 13b engine, the newer the better....

 

hey thanks all for the advice! im gonna go pick up the 87 13B.