Could someone help me put a year and model to these 12a housings....
A- 3 small exhaust ports
B- No exhaust port sleeve, small oval port, large outter diameter where exhaust sleeve usually sits

C- No exhaust sleeve but unlike "B" it has a larger oval port , also has smaller outter diameter where the exhaust sleeve usually goes

D- well pics speak for itself.. It also has what seems to be a part # written on it with a marker


I need approximate year & model car it probably would have came in... Thanks

 

A = stock 12aTD housing ( pre 1974 )
B= s2 rx7 ( 81 ish vintage )
C= 74 - 78 rx2/ rx3 12a , a real 1881-10-100a housing
D= worked 12aTD housing ( ported out ), or an unusual ( to me in oz ) version for a thermal reactor ( hence the insert with lip )
- the number on it is incorrect
( the number it has is for an early 1974 1978 SD 12a, which it clearly is not )

 

part number on D is wrong. 1881-10-100 is the 74-75 us big port big font 12a, like C

B has to be earlier than 81, or non us, as its thermal reactor. mazda sold the N210-10-100/150 here for the racers, its the euro 12a, thermal reactor, 10 degree later closing port

A and D are something like 2090-23-050's

those are sexy BTW!

 

Thanks for the info guys... These 4 housings are part of 6 others I imported a few years ago.... They are all Japan spec so I guess that's why they look so different

Now they're off to Ebay.... thanks once again

 

I've got a question. Does D have TCP in raised letters on top of the rotor housing? Mike, Tom and I were kinda curious about a set of those recently.

 

TCP?
i have seen that on the bossed writing on some old housings
i thought it was for something about the chrome sheet insert or porous channeling surface

that unusual D, considering its obvious thermal reactor nature, yet 12aTD origin
i would hazard to finger as a 12aTD AP unit for a low pollution japanese 1973 rx4
- built with a reaps stove to score a low pollution tag and government contracts
( occasionally i have seen some oz 12a TD of similar vintage with a single open port , but no stove )

 

I have a set of TCP housings. Tom found the info about them on google.