Hi all.

I have a '78 MG Midget which a previous owner had swapped in a 12a. After the intake manifold was removed recently I discovered it to be a 6 port. The actuators have been removed leaving the auxiliary ports open.

I know I will get more low end torque with the actuators installed, but is it worth the effort and cost? The car itself weighs less than 1800 pounds so I can deal with a bit of torque loss.

Here are a couple shots of the engine in question. Right now it is out of the car getting some much needed attention. I can take some more shots if it will help.

 

If you can find the parts, then yes. The torque loss without them is about 20% so it's fairly significant.

 

Is the RPM range for having them flip open the same as a 13b (around 4000 from what I've read)?

 

I went back to the shop to get a better look and it appears the previous owner welded and otherwise mangled the manifold. Can I fit another one to it? I don't see where I could find a replacement.

 

If that's the case then you are probably out of luck. 12A 6 port stuff is quite rare. You may have some luck in the Oz and Nz forum finding them. Japan2LA may be able to help as well. But honestly it sounds like it will be a major pain so probably not worth it in this case.

 

I talked to a local rotary mechanic last night and he told me it wasn't worth the hassle considering my car's weight.

Right now it looks like I am pretty limited in what I can do with the engine. Down the line I might just throw in a 13B. Physically how much bigger is it in terms of hight and length? Could I use the same tranny and if not how much different would a 13B one be compared to the one I have now?

 

Same height, 20mm longer. For the increase in power you see, the weight wont be noticeable.

Trans for both engines have same bolt pattern.

 

That's good. Thanks for the help.