britishcarfanatic

Hello: I have a MG Midget, and I am looking for a good candidate for an engine swap. I like the car, but the engine is a piece of crap. To be honest, I don't know too much about the rotary, but have heard that the 12A is a good fit in my car. I have done some research and have become facinated with these engines.

I did some salvage seaching for a donor car and found a couple- a 1982 Rx7 and an 85 Rx7. What I am really looking for at this stage is buying all the components I need for a swap (engine, tranny, accessories, mounts, etc.). I figure that any salvage engine is probably not much good, but maybe could be rebuilt or used as a core when buying a rebuilt.

The two cars- one engine was locked up, and the other turned over by hand very easily. As I am used to piston engines, is it normal for a rotary to turn over very easily by hand or is it low on compression? The guy at the counter said he was told the car was good runner, but he knows about as liitle as me about these engines. As it is a "pull it yourself" yard, I won't be able to try to start the engine.

Is there anything to look for to reduce my chances of buying a useless engine? Any other tips to this rookie would be very much appreciated.

Coal

The 13B might be a better swap as it's smaller and lighter.

I'm no expert on rotaries myself, still learning, so I'll let the other guys help you out with the other stuff

hornbm

no the 13b is larger than the 12a. The 12a is a 1.1 litre and the 13b is 1.3. As for size their practically the same, just the 13b is 20mm longer than the 12a.

The best way I know of testing for good compression in a rotary without turning it on is to first remove the spark plugs.

When you trun the engine over, you should hear a "woosh" three times, one for each side of the rotor.

Listen to this on both rotors.

The only other idea would be to use some ATF to restore some compression if its lost any.

TheTwinTurboRX-7

um the 12a is smaller than the 13b, can't speak for weight as I'm not sure what the respective blocks are mad out of but still

a rotary will turn over fairly easily by hand, either one you should probably do a rebuild on before using in your car. I would suggest the spinning one over the locked up as the locked one may have damaged rotor housing depending on how it locked up. more people will chime in shortly I'm sure.

hornbm

i think the 13b was like 20lbs more than the 12a? Probably wrong on that.

I do know that a 20b is 100 pounds heavier than a 13b though.

Coal

lol, maybe I got the wrong facts

I think I'll have to go smack up my sources, lol.

Cody

There is someone else on this board who apparently has a rotary powered midget.

I myself have a 71 MGB with an 1800 bored to a 2.0 and larger HS6 carbs. Fun little cars. I've been working on installing the sebring kit from an MGB-GT on that one.

I've been contemplating the idea of swapping a rotary into the MGB ever since I bought my Rx7 in January. I probably will someday.

Good luck!

MIKE-P-28

iTrader: (1)

jeff20b has the rotary powered mgb

hornbm

wasnt there a website about a rotary powered midgit somewhere? I dont think it belonged to jeff20b either.

britishcarfanatic

Yes there is a site:
http://www.geocities.com/mg12a/mg12a/intro.html

He is the one that got me excited about the project. According to the article, the 12a engine will go in w/o cutting the car. Custom motor mounts and a modified oil pan are required. The 13b requires some cutting. Besides, the current Midget engine has about 57 HP. I think the 12a would be more than enough me.

The donor cars both have 5-speed trannys. This would be another plus to the swap as I currently have a 4-speed and a 3:90 rear gear in the car.

What are the long term parts outlook on the 12a and the 5-speed? I hear that some 5-speed tranny parts are no long available from Toyota. How about Mazda?

Jeff20B

iTrader: (13)

It's a Midget!

britishcarfanatic, you have a PM.

By the way, my avatar pic is of my Midget's driveshaft next to three rattle cans. Almost exactly the same length.

inittab

Ah.... I was wondering what that was. lol

pratch

My dad has a Triumph Stag with a 13b. Quite a fun car

Pele

iTrader: (28)

This is a popular swap, I think this is the third or fourth person who has something related to british cars in his nick name and like the fifth or sixth MG swapper on this board.

britishcarfanatic

Thanks to everyone for the welcoming owners of other makes!

Can I ask again how are parts availabilty on 1st generation motors and trannys? Does the dealers still stock all the parts? I want to put in the 5-speed along with the 12a. Is this a good tranny or should I pick a couple spares?

Pele

iTrader: (28)

Dealer isn't the best option... Dig the vendors and info thread at the beginning of this section... Very helpful...

www.mazdatrix.com is gonna be a good bet.

britishcarfanatic

Yea, the dealer is ALWAYS my last option. I guess my questions is that I really want to do this swap, but I worry about long term parts availabilty, as I plan to keep the car a long time. I suspect that the 12A will not as popular long term to racers/hotrodder, etc. Will I be able to get engine and tranny parts say 15 years from now? Help me out guys, I found a salvage donor car that I may go buy this Saturday. I really want to go the rotary route but need some piece of mind about it.

82transam

iTrader: (18)

don't mean to steal the thread, but isn't there also a site out there somewhere featuring a rotary powered AE86?