So I picked up a used engine that I tore down to check all the specs and give it a good cleaning. When I opened it I found that it had 1 piece apex seals. Does the install process differ any from the FSM? Also it appears that each apex seal has only 1 spring, is this normal for a 12a?

 

All engines before 1986 had one apex seal spring.

Interesting that the seals are one piece, that means that they are either carbon-aluminum or ceramic, since all ferrous seals were two or three piece.

 

Yeah, I got a "mildly ported" 12a that had been in a flood for cheap as dirt9From and insurance reseller). I opened it to get all the mud out and check the condition(measure EVERYTHING) and found that mildly ported = bridge ported with 1 piece apex seals, hardened stationary gears, and solid corner seals. i could tell that all the gaskets were relatively new(they actually came off without the need of my gasket eraser).

 

if you have the carbon seals, they are like pencil lead, super light.

use the specs in the competition book, http://foxed.ca/foxed/index.php?page=rx7manual

also note the carbon and iron seals take different apex seal springs.

IMO the carbons are nice, they wear quickly, and can't handle any detonation, but they are really easy on the housings, and since they are so light sealing at high rpms is better than the iron seals