not C4 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 C4 owners. a few nights ago, 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. (here is the thread to the GS's restoration: http://www.rx7club.com/showthread.php?t=822222) 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:

 

here are pics of the rotors:

#1 rotor:





#2 rotor:

 

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

 

here are some of the pics of the parts that were hot tanked and cleaned:

bad housing and rotor:

 

good rotor and housing:









rear iron where the apex seal spring lodged itself between the rotor and the housing near the intake port:



the stationary gear on the rear iron:

 

WOW!! First one of these i have seen in like 20 years.I had a RX 7 as a teenager ,.I tore it down to fix a few oil leaks and never did get it back together.Later on i discovered the chevy 350 and never looked back.That mazda was a chick magnet but i didnt have the skills to keep it going.

 

Nice. Wish you where closer. I've got a friend that's in need of his 87 RX7 (that's a 13B right?) engine rebuilt. It's been sitting in a storage unit now for almost two years. It was a great car...it's so sad.

 

I rebuilt one of these engines once. Choice supplies are rubber bands, vaseline, and a tow vehicle to get them started for the first time.

 

cool set of pics bro, I have never seen the inside of a rotary engine; and as I am looking over the photos, I cannot understand what the heck everything is and how it works. I know the triangle shapes act as a spinning piston, but it sure doesnt look like there is much room in that block for them to turn?

 

They are way cool to see how they work.
Rotary in Action

 

Ahhhhhh ....if only it were that easy.

 

i'm glad that i was able to share these pics with you guys! i hope to tak emore after i clean more parts. i forgot the front cover at the machine shop where i was cleaning the parts up at..

 

These things get rebuilt? I figured they were just pulled and replaced with SBC's...

Cool pics they're neat motors.

 

yes they get rebuilt, lol. i can't put a SMC in an RX-7..thats just not my style...although it would be an awesome package, especially with a 6spd. Chevy did build a rotary powered Corvette though! never made it to production but it still exists!

 

ok, here are some pics of the eccentric shaft and the front iron and stationary gear. none of these parts were hot tanked as of yet. the e-shaft was not hot tanked because i didnt want to take any chances of it rusting (will coat with light amount of oil after hot tanking). this is a very nice e-shaft and it, like the front iron, were only wiped down.

 

really cool animation; I am especially impressed with Scoot's 4 rotor RX7 that sounds like a freakin' F1 car! So is one rotor equal to 3 cylinders?

 

well, i would say no, as the displacement for the 12A is only 70cid..so, half of that would be 35cid and would equate to say roughly 50hp. way too small for a 3cyl.. say, maybe if we were talking in terms of the late Chevy Sprint with the anemic 48hp 3cyl then we may be able to compare a one rotor to a 3cyl

 

I once built a RX-7 with a SVO motor. It was a 1981 was pretty quik car with that turbo 4 banger.

 

I wasn't questioning equal displacement, it looks like the rotor has 3 cumbustion surfaces, so does it 'work' equal to a 3 cylinder engine.

 

There's a guy around here with a little Opel GT with a really modified Mazda rotary engine in it. He's run the thing in open road racing at 140mph !!! It's a freaking little rocket!