tonight i decided it was past time to tear down the 12A that originally came in my ocean blue 85 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:











#1 rotor housing:





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:

 

Yeouch. Time to break out the oven cleaner.

Intersesting crimp on that corner seal, once the apex was gone.

 

corner seal came out in two pieces..that poor rotor is wasted..

 

Bookend.

 

wow not much to save out of that motor. for the worst rotor i have seen in awhile

 

Interesting Dave - that crease on the side of the rotor near the tip... wow! Some failure. Hows the e-shaft?? Looking for a display one if its not all scored up...

Stu Aull
80GS
Alaska

 

Stu, the e-shaft is actually the best part of the engine! definatly one worth using. my intentions are to clean the parts in the hot tank, spec the irons, coat and shelf the good parts, and sell the rest as decorative items for rotary fans.

 

I love me them rotor paper weights lol

 

spent the evening in the machine shop cleaning the parts..i'm tired. really is a lot of work..

 

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

 

Where are the pics..???

 

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:

 

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:

 

Damn those came out clean, you must have spent forever scrubbing away at them!

 

I think he said he hot tanked them. The rotor housing looks painted it's so clean.

 

yeah, they were hot tanked...for hours, lol. the aluminum cleaned up extremely well! the front cover looks brand new!

 

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.

 

here are some pics of my rotary powered cars and pics of the engines. good for comparison purposes and for those that aren't familiar with other rotaries.

my 1980 LS 12A:







my 1985 GS (with 13B):







85 GSL (12A) sold the car last year:

 

my 1988 10th Anniversary:







my 05 RX-8:

 

Since you drive both a 12A and a FI 13B SE - I'd be interested in hearing your thoughts on the difference in engine performance. I've only ever driven a 12A and will be doing the 13B SE transplant in the coming months (years?). I'm just wondering if it's a noticeable improvement.

 

going from a 12A to a 13B is a HUGE difference. the smoothness of the SE's 13B is astonishing and the power is very nice! i have no regrest what so ever and encourage the swap!

 

I'll use this as encouragement to complete my swap sooner rather than later.

Thanks
g-man

 

can't figure out how to delete it...sorry..