Putting in 1275 motor into 1500 Midget

[Thor]

My question is can anyone share their experience or thoughts about replacing their 1500 engine with the 1275?

I have access to a complete 1275 engine bay including transmission, engine, radiator, etc. Doing so would give me drivebiltiy while I can take my time rebuilding the 1500.

Did much change in aspects of the car body that would prohibt me from doing this easily? Also since the 1500 didn't give much performance enhancements over the 1275 do you think I would notice much loss of performance? Certainly there are more enhancements for the 1275 and perhaps I could add some to get an extra boost of power.

Thanks

 

[LeeMcKee]

I'm doing the same thing with my 78 midget.
The 1500 is a "good" engine but I think the 1275 may be a better one. The 1500 has a little more torque but the 1275 can rev higher. I've been a Triumph man for many years and I like the 1500 but the 1275 is a more relieable engine. Besides the 1500 has a fatal flaw in that the thrust washer on the end of the crank is cresent shaped and will fall out over time, When it does it will eat out the block and eventally your connecting rods or crank will fail on you. (Normally in a spectaulor way!)
I am planning to run my midget in some vintage races in the future so I HAVE to change over to a 1275 for that but If I didn't have to I would leave the 1500 in her and just stay on top of the engine matinence. There are quite a few mods for the 1500 engine, just venture over to the Triumph spitfire side for a little while and you will see them. Spitfires do pretty well at vintage events so they must be doing something right.
Other than that the transfering of the engines is more or less straight forward. You will need the trans for the 1275 and a new drive shaft. And while your at it the speedo cable is a little different as well as some other bits and pieces. If you don't feel like driving the midget for a few months then it can be done but if your not racing the midget in vintage or if your not trying to give the car a older appearance by removing the rubber battering rams and such then it is not worth it in my opinion. Some people remark that "It's a sin to have a Triumph engine in an MG" But the midget(sprite) was designed by Donald Healey for Austin Motors (of course). So, what you have is an Austin-Healey with MG badges and a Triumph engine. I don't see any thing wrong with that.
/ubbthreads/images/graemlins/driving.gif

 

[Bugeye58]

Other than a few bits, like the previously mentioned driveshaft, and a new exhaust, the 1275 is a virtual bolt in.
I think you may be pleasantly surprised at the result.
You may want to find a 3.9 rear gear for it, though.
Jeff

 

[aeronca65t]

I'm doing the exact same thing as Lee (and for the exact same reason). I expect it to be pretty straight forward.

 

[Hap Waldrop]

If you're into modding the engine, then you will love the switch, there are more 1275 speed goodies available than you can shake a stick at.