tore down another 12A - Toyota Nation Forum : Toyota Car and Truck Forums

mazdaverx7 · 10-29-2009, 08:10 AM

not Toyota specific, but perhaps interesting to those who have never seen rotary engine internals. since i restore RX-7's as a hobby (that my wife hates), i had a good time so i thought i would share with my fellow Camry owners. last night i decided it was past time to tear down the 12A that originally came in my ocean blue 85 RX-7 GS which i converted to a 13B car, powered by the 13B from a GSL-SE. this engine was locked up when i brought the car home. i tried atf for days and gave up and pulled the engine. i saw the engine sitting on the garage floor tonight and decided to tear it down just to see what the issue was. it looks as if an apex seal let loose on the rear rotor and when it broke apart, it let the apex seal spring fly out and lodge itself between the rear rotor and the iron. it came apart nicely with only minimal fighting. the engine had 142K on the clock and was heavy on the carbon buildup. the rotor bearings look nice but the housings have some flaking and wear. i don't know that i would even attempt to reuse the #1 rotor housing. its in fair shape imo. the rear housing is trashed due to not only the flaking but due to the apex seal shredding itself in the housing. here are some of the pics i took of the engine internals:
rear iron:

#2 rotor housing:

[IMG]http://i605.photobucket.com/albums/tt134/mazdave/DSC09253.jpg
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#1 rotor housing:

[IMG]http://i605.photobucket.com/albums/tt134/mazdave/DSC09250.jpg
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intermediate iron:

mazdaverx7 · 10-29-2009, 08:11 AM

here are pics of the rotors:

#1 rotor:

#2 rotor:

mazdaverx7 · 10-29-2009, 08:11 AM

here are a couple more pics from earlier in the evening during the teardown:

[IMG]http://i605.photobucket.com/albums/tt134/mazdave/DSC09255.jpg[/img

ghettosled · 10-29-2009, 12:39 PM

that is very cool. thanks for posting up the photos. i dont know how true this is, but ive always heard those apex seals are the achilles heel of the engine.

mazdaverx7 · 10-29-2009, 12:58 PM

yeah they really are. they serve as a comperssion ring of sorts and once they crack compression is lost.

#2! · 10-29-2009, 03:18 PM

Iv always had a interest in these but never had the opportunity to get into it. Thanks for the posting those. What Iv always wanted to see was Weed Wacker powered with a high rev rotary engine.

Whats your take on the Edwards Wing Rotary?

mazdaverx7 · 10-30-2009, 08:14 PM

never heard of edwards wing rotary. i try and stick more so with oem restorations.. on a side note, i got most of teh pars cleaned up. i took them to the machine shop last night and i spent a few hours cleaning the parts. i may take some pics later tonight or tomorrow after work.

EverReady · 10-30-2009, 09:21 PM

13B for the win, currently half rebuilt, spending hours and hours trying to clearance the side seals are killing me :/

mazdaverx7 · 10-31-2009, 06:05 AM

looks like you have a great start! just be patient when installing the side seals. once the seals are in place, i like to wrap the rotors with a rubberband. how are the housings? any flaking? what are you putting the engine in?

***LynchburgCSI*** · 11-01-2009, 12:46 AM

rotary engines... sooooo cool.

mazdaverx7 · 11-02-2009, 08:54 AM

i have the day off and i have the clean parts laid out in the garage. pics to come soon!

mazdaverx7 · 11-05-2009, 08:22 AM

ok, i went out and took a few pics ths morning. i've been busy working and rebuilding the diff on my 80 LS and i got lazy with taking these pics. here are some of the pics of the parts that were hot tanked and cleaned:

bad housing and rotor: