So I happened to get my hands on a 1979 RX-7 for free. It quite possibly needs a new engine. So I'm curious as to if a 13B twin turbo will fit into the first gen.

 

Yes. Do a search. A lot of work, though. Consider just rebuilding the 12a. Pull it out, take it apart and then you'll know what you've got. If you end up going the 13b Turbo route, document it with plenty of photos. We'd love to see it. Good luck.

 

There's a lot of work needed to put a twin turbo Fd swap, in a SA chassis. It's not even worth it especially if it's your 1st rotary. I would recommend a 13b N/A swap relatively more common and easier to swap, that doesn't require transmission swap and a overhaul. If you absolutely want to make it a turbo, I would use a 87-91 FC Turbo 2 swap. That's usually what people use when they make 1st gen Rx-7 turbocharged.

FD swap single turbo done correctly 6-7k in just parts no labor
Turbo 2 swap stock with at least a standalone ecu. 4500-5500
N/A 13b swap is a lot cheaper less fabrication
Just a rebuild on a 12A even cheaper!

These are just ballpark numbers its really hard to gauge pricing. There's nothing out there set and stone, but if you need a rebuild done. I'm located on Tacoma.

Sammy

 

own a 79 rx7 is the any engines that are not rotary that I could swap in?

 

This thread is 7 years old, and your post is barely legible. I don't think you're going to get an answer.

 

Any engine will fit. It just depends on the amount fabrication that is required.

 

And most importantly lets not forget the OP's budget.