I'm new to the forum. My dad has decided to fix up his/my old '79 RX-7.

I was wondering what the most common engine swap was with this model.

 

I'm sure the most common swap would be the 13b 4 port cosmo engine. It's a direct drop in, I have on in my 84, gives you a couple extra horses.

 

I'd say the TII swap is pretty common as well. Just search for TII swap or engine swap, or anything like that and see what you come up with. The TII swap used to be a sticky I think. Good luck.

 

You've gotta slot or swap a couple things, making both ideas posted above almost direct drop-ins. Plenty of useful info about such swaps can be found here as quite a few users have done it. I even replaced a '73 12A with a '74 13B in an MG Midget (lol I didn't do the original piston to rotary swap though).

 

In reality most people do not do an engine swap but rebuild what they have and perhaps have a street port done. Quite a few people get a 13B with a carb to avoid the cost of installing a fuel injection system. The problem with the latter is the engine will be old and most will need a rebuild.

You are talking about 140hp which is a reasonable amount for a daily driver.

If the 12A is rebuilt it will be strong enough to taka a blow thru turbo. This can be done with minimum problems and reasonable cost.

The next step up is to drop in a 13B turbo with 180+hp. The budget for this can be $5000 plus, way more than the value of the car. If you intend to keep the car for many years, like performance, and have the cash, its an option tried by quite a few people. I would suggest about 5% of gen1s went down that track, and the majority of their owners are members of this forum.