Alright my 12a control rings are gone, so I am going to pull it. Going to rebuild it, and save it for a Opel GT or 1970 Triumph GT6 coupe, MG you know something cool that needs a streetport....

Whats the best way to put an S5 13b in? Weld up some motor mounts, and use the stock mounts off the motor? Or can you use mount it like the 12a... will the 12a front cover work on the 13b, or am I thinking wrong?

What do I need to make a carb'ed 13b work, and what will carry over from the 12a? The 12a has a Weber 45 on it right now, so I was going to get a upper manifold section from RB that lets you use the stock lower off the 13b. So I guess that leaves ignition system...

 

You need the front cover of a 13B from a GSL-SE or 12A ( not sure 12a works) and the GSL-SE tranny crossmember, check the FAQ for first Gen, but since you want to drop an S5 in it , why you dont want to go turbo? Might as well go all the way, just my 0.02.

 

12A Dizzy and DLIDFIS is a perfect choice for a carbed 13B. My MG Midget has a 13B with a 12A front cover and an R5 oil pan. The motor mounts and trans mount are competition versions (required to keep it from rocking left and right). The carb is an RB Holley. The exhaust will consist of a long primary with RB presilencers and magnaflow mufflers. I bet it will sound like rotary heaven.

 

If I could I would, but I have the spare S5 block in my driveway, so that's why.


That dose sound like a slice of heaven! Do you have photos of all it?

 

I have a 13b header available

 

I know the RB street 13B headers end in a different spot than the RB street 12A headers do.

I have two complete exhausts one for the 12A and one for the 13B, and I just have to swap them when I swap the motors.

 

Thanks. I think I am going to try, and copy my RB headers off my FC first. If I cant I will keep you in mind.

 

you will also need the GSL-SE oil pan so that the oil pan clear the center steering linkage.

 

Yep.

If you can find one, the GSL SE subframe and motor mount plate will drop into your 12a slot no problem. I was lucky enough to pick up a SE parts car that was wrecked in the back. Gave me everything I needed to put a TII motor in save the throttle cable and a few misc components.

I've been unable to confirm if the motor mount plate is the same 12a vs 13b SE, or if it's just the subframe that moves the motor mounts themselves.

 

Same. It's the motor mount pedestals that are 20mm forward on the GSL-SE main crossmember. Now you know.

 

Yeah, but you can just wedge it in there.

Next time my 13B comes out I'm gonna actually drill proper holes in the mount.

 

I always use stiff motor mounts so I have to get the holes aligned well before hand.