Just wondering if anybody's tried to swap the 1.8L BP engine from a miata into the 1st gen RX7s. I googled it and turned up nothing, and I think it'd be really badass to do. I dunno how the tranny from the RX7 mates up to the BP, and I know it'd be a lot of work, but there's nothing that a machine shop and some time can't do.

pease out

 

Easiest way to do it is get the miata engine and tranny, then get a custom driveshaft (if necessary). Engine mounts can't be too hard.

 

That would be unique. Usually it is done the other way around, putting the RX-7 rotary engine in a MX-5 Miata.

 

LMAO!

I don't know if you realize, but your title is very decieving.... On this forum "BP" usually means "BridgePort" - a way to port a rotary engine.... So here I am wondering how in God's name you'd get a 1.8L bridgeported rotary.... a "20b" but made with 12a housings might be about the right size

But of course, I don't think that'd ever fit in a miata's engine bay!

Good luck... I still think it's stupid to put a piston engine in the only production rotary car of the '80s.

Jon

Edit: BTW, do a search here for miata tranny or related terms... I remember someone saying the transmissions were near identical, so maybe you just have to change the bellhousing on our tranny and keep it in place... Look into it. There was a site that compared the transmissions between Mazda B-series trucks, miatas and Rx7s. Look for web sites that show the swap of a rotary into a miata, and you'll get lotsa useful info, even though it's the opposite swap that you're doing. If you see rotary engines being put into miatas while keeping stock tranny, you know you have your answer.

 

I know that the miata transmissions were based off the first gen trannys. I think you can change the bellhousings. I am not sure if you would be able to put a bellhousing from a miata engine on a T2 transmission in case you wanted the extra strength (when turbo charging the 1.8-which takes 400hp). I would modify the rotary. Piston engines suck for the most part, the 13b (or properly modded 12a) takes more power than the miata engine, would be cheaper to mod, easier to mod, handle the power better, and would not offset the handling of the car like the 4 banger would.

 

along those lines, has anyone swapped a 6-speed miata transmission into a 1st gen? i suspect that could be a neat little project.

 

Miata trannys are WEAK. The rx8 tranny is a modified miata tranny and people are allready blowing them

 

Driveshaft not needed. RX-7 and Miata use same trans. Swap to an RX-7 tailhousing so that you can use the stock crossmember instead of fabbing some PPF-mount-to-crossmember adapter block, and then the transmission placement determines the engine location.

Engine mounts would be like 50% of the swap, the other 50% being the wiring, if you didn't want to convert to a distributor and dual DCOE carbs (the ONLY way to fly for a DOHC four).

 

And the Miata 5-speed is the one used in RX-7s anyway, except the Miata trans has much better ratios. (Except it uses the inferior fine-pitch gears that Mazda introduced in '82ish, whereas the early RX-7s had Real Manly Gears in them)

 

is that to say NA rx-7 trannies are strong? because everything i've heard is contrary to that.

i'm curious as to how well a miata 6sp's ratios would match up to a rotary.

 

Thread From the Dead Alert!!

I used "Miata transmission swap" as keywords in the archives and in this section and only six threads popped up. Of those, this is the ONLY thread with a clear reference to what I'm contemplating now that I've power-shifted my '83 GSL tranny to death.

Does anyone have the answer? The linked sites talk about pre-'99 Miata 5 speeds, but ignores the 6 speed citing its ratios only as reference.