well just like the title says im thinkin bout doing this... are the mounts the same as the rx7? if not, are there any aftermarket mounts already custom made for this swap? how much hp will the stock miata rear nd hold?
thanks guys
jack

 

Put a 13B-T in a Miata is not a simple task, it does not just bolt up obviously. You will need to fabricate your own engine mounts, raise the transmission (since the rotarys eccentric shaft is in the center, not on the bottom like the miatas 4cylinder crankshaft) and do some other modifications. The stock Miata rear end will start breaking easily around 250RWHP, I installed a compete 3rd gen RX-7 drivetrain in my Miata to handle the 310RWHP it puts out on pump gas.

 

www.rotarymiata.com

it ain't easy, but it can be done...

 

I know Scott at Mazsport was making a kit so you can just bolt it right up to it.

Mike

 

Drop me a pm and I'll give you all the details neccessary to do the swap!
It's not as difficult as most people claim. Most of the parts needed can be swapped from a 2nd gen TII chassis.

 

ooh, crispeed could you just post it so that everyone can know

 

PLEASE!

That is my dream car right there

 

I wanna know too

ecarter_umr@hotmail.com

 

good ... im so hyped up bout this project
hook me up with as much knowledge as u can... please no flames!
if u can hook me up with that info crispeed it would be grrrrrrrreat!
thanks again everyone and keep that info coming
thanks
jack

 

Its not as tough as putting a 20B in a 3rd gen, but it aint simple either. With all the parts, fabrications, and labor with me doing some of the work I think we came up with a price tag of about $10,000 including a rebuilt S5 Turbo motor from Pineapple sans core. This was utilizing the stock miata transmission and rear end, unlike the 3rd gen assembly that now resides in my Miata. I just decided to build the motors bottom end and turbo it, 310RWHP, 340 torque on pump gas and 380 on race gas and not breaing differentials is going great. Total cost was about $9,000 including custom turbo kit, Tec III engine management, gauges, pistons, rods, and couple other things.

 

well damn u must have some nice *** cars then!!! nice... if u know where n e info on this subject is please just place it in this thread
thanks
jack

 

OK!
Here goes!
1st part!

You'll need an oil pan/sump and oil pickup from an 84-85 rx-7 GSl-SE 13B motor.
You got to mount the oil pan in the reversed position so you'll need to re-drill a couple of the holes and also lengthen the oil pickup to work in this new position.
I mounted the motor using the front cover from the same year motor also. The front cover got the same turbo oil return hole as the 12A Turbo from Japan but it's not drilled out. I also believe the USA 84-85 12A got the same oil return hole.
I made a soild crossmember that was bolted to the front cover and to the frame rails to mount the motor. There were no vibrations doing it this way plus I was planning on making a lot of power and didn't want anything moving around.
The stock Miata crossmember also have to be notched a little to accomodate the wide rotary oil pan. This was done at the rear part of the crossmember.
I also used the non-powered steering rack because there were some interference problems with one of the lines coming out of the powered rack. You could modify the power rack by moving the line if you wanted to I believe.
The 89 to 91 AC compressor worked out for me as it got the same mounting for the AC lines as those on the Miata's AC system. The shorter radiator and oil cooler from an early 1st gen Rx-7 also worked fine. I used electric fans with that setup. Also you can use the Miata's alternator or one from the 89 to 91 rx-7 as it also got the same electrical plugs as the Miata's. The factory gauges were also used via the Miata's stock oil pressure sending unit for the oil pressure gauge and I used the rx-7 water temp sending unit for the water temp gauge.
End of 1st part!
On the 2nd part I'll deal with drivetrain choices mainly trans, rear and axles etc.
Any questions?

 

well the easy way for part 2 is to put the miata tailshaft housing onto an fb/fc tranny and it will use the stock miata driveshaft and power plant frame

mike

 

That's for sure the easiest way!
It's also the quickest way to send NA trannies to scrap yard heaven in the sky!

 

hahaha... u still have this car crispeed? ne pics?just wondering because i was a bit confused on the reversed oil pan and drilled hole out of the front plate. well thanks for all that info . it was very helpful...
what about using the stock intercooler ? a front mount would be the way to go huh? well thanks
jack

 

There's this guy in VA that has a rotary in his miata. he said it put him back 15,000 and took the person 6weeks to complete.

 

where is the second part at ??

 

AFAIK, Mazda didn't want people buying Miatas to put 13B's into them, so they purpusely designed the steering rack so that it would interfere with a 13b, thus discouraging engine swaps.

 

How can you speculate that Mazda did this on purpose?

 

mazda is coming out with a rotary miata soon........

 

i heard rumors about mazda producing rotary powered miatas.................hmm and a 4th gen rx7........i dunno where i read it from. anyways, i'll be waiting for part 2

 

Think about it. The Miata is everything an enthusiasts car should be, it's lighweight, RWD, well balanced. It has all the makings of a really good sports car, except that its underpowered. Mazda was sitting on a really powerful compact engine, that it wanted to put in a higer end sports car, so they could make some serious money out of it. If the new engine fit in the Miata, everyone who wanted a track car would put a rotary in the much cheaper miata, which would equal tons less in Rx-7 sales for Mazda.

from http://members.rogers.com/sofronov/C...9Roadster.html I found this
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Dave Lemmon of Mazdatrix proved that a 13B turbo motor will go into a Miata, but not as easily as might be suspected. Although the rotary is compact, its parts are in all the wrong places for the Miata, the sump needing surgery to clear the front crossmember and the right side of the front subframe needing a trim to clear the turbo. Bigger brakes, drivetrain mods, and cosmetics are all part of what $10,000 plus one Miata, a donor 1989-90 RX-7 Turbo, and wheels, tires, shocks, etc. can buy you
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And I definitely read it somewhere, just can't find the site right now. It makes sense from a business standpoint, doesn't it?

 

Enh... I don't know that I buy that, for the simple reason that I can't believe there would be much thought about how good of a track car something would or wouldn't make. I'm pretty damn sure that, statisticially, the dent a rotary powered Miata would make in sales of RX-7s for the reason you mentioned would be pretty insignifigant. I mean, as much as we're disproportionately large of a population on places like here... I sincerely doubt that all that many people *have* track cars.

 

im going to hop in here and say if there's thoughts of a gen4 rx7(under a different name due the the rx8 now) some people are going to call it the rotary miata and others are going to call it the 4th gen 7

In my eyes who cares...

im in the works of a rotary miata myself w/ jbe racing's help.

I currently have a turbo 1.6 that is tuned to push 1.2 bar. Im building my rotary miata from the rear to the front (took care of the diff and axles first). I must say thanks crispeed for the info about a year back about the ?was it an 84 sump? spun 180 and other great treats.

to be honest 20b was the original plan, damn thats alot of work!

 

If your interested in convertine your Miata to a full blown Rotary Rocket give us a call

MAZSPORT : 727-530-9960 Monday-Friday 8AM-5PM

We have developed a rotary conversion kit.

Please ask for Scott if calling and he will give you all the information you are looking for.

-Markus Reschny