fitting midet 1500 engine

[ugg90]

Hi, i have just purchased a herald with a dodgy engine, but my friend has a 1500 Midget with a good engine. i have been told by rimmer bros that you can swap engine with very little trouble. can anyone advise me of any problems i might encounter. Also after some black door cards without speaker holes in them.

[Tim Bancroft]

Easy job to swap in the Midget engine as basically the same engine.

Door cards try Canley Classics 01676 541 360

[heraldcoupe]

There are a few complications in fitting a 1500 engine into a Herald. Firstly, if the Herald is a 948 or early (pre June 1962) model, forget it. The engine mounting points on the front plate are different, while anything larger than an 1147cc unit will tear the chassis apart in short order.
Assuming your car is actually built on the post 1962 chassis, you will still have a few issues to deal with. The clutch is your first consideration. Heralds were fitted with a 6.5" diameter clutch, the 1500 clutch was 7.25" diameter. Add to this the fact that the Herald gearbox has 10 splines on the input shaft while the 1500 gearbox has 21 finer splines, you can see that a special clutch plate is going to be needed (part number GCP103) use the rest of the clutch fitted to the 1500 as you will need the larger diameter to handle the torque. Pre 1966 Heralds also had a coil spring clutch which uses a different release arm and bearing assembly, make sure that what's fitted to your gearbox matches the clutch.
Next issue is the manifolding. If your Herald is a 13/60 then you will be able to retain the exhaust manifold for use with the 1500 engine, the inlet and exhaust port design being the same between the two engines. If you currently have a 1200 engine then you will need to acquire a suitable exhaust manifold, the Midget item is quite different from Triumph types because of the clearances in that car's engine bay.
Finally, bear in mind the 1500 engine's dreadful reputation in the Midget. Whilst the engine's only real weakness in it's Triumph applications is a tendency to wear out it's bearings, in the Midget they are known for throwing rods out the side of the block! The main reason for this is the poor airflow around the bottom end in the Midget, the bottom end can get much hotter causing the big ends to seize. The Midget was never available with overdrive, so the engine is likely to have been worked harder in this application.
There may be other issues with interchangeability between MG and Triumph versions (is the sump different?), but that's all that I am aware of.
Cheers,
Bill.