antiSUV

iTrader: (10)

Are there any internet or print references that would tell me what all the viable engine/bell housing/trans combos there are? Like which pieces from different years fit together? Or does this knowledge only come with experience, and is not recorded anywhere?
Im just talking about Mazda rotary drivetrains here.

I'm just full of questions...

Felix Wankel

For the engine to trans bolt pattern, you have pre -74 and then 74 and up. Crispeed has said the TII bellhousings fit the old ribcases, save for one bolt. N/A RX-7 trannies are cast with no bellhousing.

antiSUV

iTrader: (10)

Thanks...

So does this mean a N/A FC 13B should bolt up to my ribcase 4-speed without troubles?

Felix Wankel

As long as the trans is a '74 or newer. Although you may want to double check for flywheel/starter clearance. Pre '83 cars use a 215mm flywheel as opposed to the 225mm of the later NA cars.

Edit: On a side note, you'll need a downdraft carb if the trans is made for a top mount starter. A sidedraft or the stock FI won't fit. I'm not sure if they even used them after 73 though.

peejay

Top-mounts were only used on twin dizzys IIRC.

Clutch size has nothing to do with flywheel diameter. The starter/bellhousing of earlier trans clear the 225mm clutch flywheel no problem. In fact that was the exact setup I was running before - newer engine with 225mm clutch flywheel bolted up to an earlier trans. They are interchangeable as far as the tranny goes.

Incidentally I prefer the 215mm clutch... less rotating mass on the transmission input shaft means the synchros have an easier time. I noticed a minute difference between 215 and 225 with the same transmission.

antiSUV

iTrader: (10)

Thanks again for help people...

...Trying to blindly feel my way into the world of wankeldom.

Jeff20B

iTrader: (13)

I've got some questions. Is the gearbox section of a TII tranny tilted like all '74-'78 trannys are? Or is it level like the twin dizzy RX-2 trannys are? Is the ring gear the same diameter on all '71-'92 NA flywheels?

Felix, the 13G used a top mounted starter.

Felix Wankel

I recall my TII trans being level, although I've never seen a 74-8 trans to compare it to.

antiSUV

iTrader: (10)

OK cool...I will use the 225mm one then, becuase the 2nd gen RX-7 had the same flywheel and clutch as the 88-92 MX-6/626/Probe, and I have a few of those lying around. (Or at least, I will try it to see if it works.)

Jeff20B

iTrader: (13)

Felix, check out http://www.geocities.com/cd23c/cars.html#mg and look at the two engine bay pics. One is a '71-'73, the other is '74-'78. Especially check out the tilt and bottom starter hole of the '74-'78.

If that's too small, I've got the same pics in 1024x768 size. I also have a new pic of the '71-'73 tranny from the side sitting on my garage floor. http://www.geocities.com/cd23c/pics/rx-2_tranny.jpg (you do already know how to view geocities pics, right? If not, I'll post the info in a while)

By the way, I've got new pics coming really soon.

Felix Wankel

Hehe I have two of those old RX-2 trannies.

That 74-8 trans looks remarkably similar to my TII one, save for the bellhousing-to-trans bolts. I'm heading to my friends shop later on, and I will look at a TII trans thats sitting on the floor and double-check to be sure.

peejay

Flywheels are NOT interchangeable between rotaries and boingers. Period. Dunno about clutches though...

The T2 trans should look similar to the ribcase... they're the same design, just beefed up a little for the turbo.

antiSUV

iTrader: (10)

OK thanks. I know the clutch is the same for sure...wasn't positive about the flywheel. There will probably be a flywheel stuck on whatever engine I end up buying so maybe it doesn't matter.

Jeff20B

iTrader: (13)

Felix, I would have liked to use a TII bellhousing on my '71-'73 tranny in my MG but I couldn't because the tranny tunnel is so small that the tilted gearbox of the '74-'78 just barely lets a bottom mounted starter fit. The TII has a starter that mounts further out. That would have been too far for me. I had to get an '86 NA starter because it is the smallest one made that still fits. It fits within a few mm of the frame rail. I wonder if it's going to hit upon deceleration?

Here are those larger pics I mentioned.

http://www.geocities.com/cd23c/pics/mg_rx-2_1024.jpg
http://www.geocities.com/cd23c/pics/mg_repu_1024.jpg

Click the links, then drag the little e (located just left of the http://www etc) and drop it onto the url itself (yep, drag it 1/4 inch to the right and drop it on the http://www.geo... etc part). It somehow refreshes the page in a better way than hitting the refresh button. This only applies to Internet Explorer users, but Netscape may be similar. This technique has yet to fail on geocities pics and sometimes even works for tripod and anglefire pics too! Too bad it doesn't work to post picks on a BB though.

Jeff20B

iTrader: (13)

I have another question. How hard is it to bolt a TII bellhousing to a '71-'73 tranny? If it can be done, is there some sort of flywheel/clutch disk combo that would work? Like a TII flywheel and an NA splined disk? If so, then I'll have a shorter than normal tranny that'll fit nearly anything from '74 and up. It'll open up all kinds of rotary into small boinger car potential.

peejay

AFAIK they only make swap disks to go the other way - N/A diameter with T2 splines. You could try hunting down a clutch disk that is 240mm (appx. 9.4488 or put another way appx. 9 7/16") in diameter but has 22x15/16" splines - that's T2 diameter and N/A spline.

Jeff20B

iTrader: (13)

Thanks peejay. Back to the drawing board.

rxtasy3

iTrader: (2)

From my experience, the trans to back of engine r all the same. T2 and the rx4 and repu ribcase trannys r interchangeable. The only prob I've run into is the starters. The rx4 starter is bigger and can't be used with any of the trannys that have the bell housing and case all one piece, which would be all non turbo 7's. To be safe, try to use a simular year starter as tranny.

Jeff20B

iTrader: (13)

My experience seems to contradict your experience.

Did you know the '71-'73 trannies are 40mm shorter than '74 and up? Isn't the T2 middle section (ribcase part) straight compared the the tilt of the '74-'78 mid sections? My REPU starter is huge and it fits my SA smoothcase tranny just fine (for all I know the RX-4 and REPU share the same starter, since they were manufactured in the same years. If anything, the REPU unit would be bigger since it's a truck part).

Felix Wankel

Jeff, I looked at an 89 TII trans yesterday, and the ribcase part was tilted toward the drivers side relative to the bellousing.

rxtasy3

iTrader: (2)

That's possible, Jeff, since I've only delt with the '74 rx4 trans and 1st gens to '83. The rx4 trans I have has the tilt towards the driver's side.

Jeff20B

iTrader: (13)

Felix are you serious? Wow that's cool! The FD mid section is straight according to some pics I've seen. Soon I'll get an upclose look at one so at least I'll know how the FD trans are. I still need to get a good look at T2 though. It just broadens the amount of boingers a rotary can go into.

Felix Wankel

I would have taken pics, but my camera went AWOL. If I can borrow one, I'll take picture of the S4 and S5 TII trannies.