One gearbox design for different engine cc's ? ~ power upg

[Tomas O'Cuplæ]

Hello,

While digging some technical service manuals (AP Service Manual) it occurred to me that the manual is actually written for Mini/1100/1300.
So many of us are pondering of a possible power upgrade (1000 to up) and if our gearbox would actually by strong enough...
Am I wrong in believing they are strong enough, as the manual is written for 1300 engines too (out of the box 60HP) and there seem no significant differences in the manual !?

Thanks 

[limby2000]

The gearboxes made after 1992 seem to be the stronger, as they have 3x plate forward clutch as standand. These will all be 1275 boxes though, but are interchangable.

[Tomas O'Cuplæ]

I admit I haven't gone trough the manuals yet... but can 92-clutches be put in pre-92 boxes ? 

hmm... it would be nice to have an overview of which automatic boxes do exist and to what engine they are originally bound too ?  
And to know what box can be coupled to what engine block ?
And what pieces are interchangeable ?

Thanks

[notamini]

If the engine is an A or A+, the auto box will work. As for transferring parts between them, some are different but I don't know which. The clutches and bands are interchangeable as whole units but may not work in bits. It is actually recommended to upgrade from the older types to the newer types.

Even after the 1100/1300 ADO16 cars there were others that sported the A+ such as the Metro.

Mark

[Tomas O'Cuplæ]

Maxi and Allegro ... running 1500 and 1700 engines on the 'same' AP box ... So I really think there's some potential ? 
It's indeed now just a question now to know what can go where / interchangeability ... 
It would be interesting to know if some of the people here have Maxi or Allegro's ?

Thanks

[limby2000]

Only the 1275 allegro is compatible as the bigger units have a totally different ohc engine, hence a different box. As for power upgrades, apparently a turbo auto has been done but the upgraded disc,s and bands are custom made and very expensive. My own engine is 2-3 months away from firing up and that has extensive mods. Your best bet is to pick up a vandenplas metro engine, 72 bhp ,but not sure if the auto vp was running the same spec.

[Tomas O'Cuplæ]

Do you have a reference for that turbo setup ?

[limby2000]

You,ll have to speak to Martin (MRA) on here as he,s A,p guru, He builds, sell,fixes and supplies all parts and special tools you may need. He has his own machine shop and has even made me a part I could,nt get elsewhere. He,s had a hand in these powerful auto,s.

[mra-minis]

Jun 21, 2016 15:28:28 GMT Tomas O'Cuplæ said:

Maxi and Allegro ... running 1500 and 1700 engines on the 'same' AP box ... So I really think there's some potential ? 
It's indeed now just a question now to know what can go where / interchangeability ... 
It would be interesting to know if some of the people here have Maxi or Allegro's ?

Thanks

These use an AP3 box not to be confused with AP1 & 2 but there are ways to reinforce the AP2 unit to take more power reliably, I have uprated plates made for me to my design, not cheap but effective.

[mra-minis]

Jun 21, 2016 20:27:54 GMT limby2000 said:

Only the 1275 allegro is compatible as the bigger units have a totally different ohc engine, hence a different box. As for power upgrades, apparently a turbo auto has been done but the upgraded disc,s and bands are custom made and very expensive. My own engine is 2-3 months away from firing up and that has extensive mods. Your best bet is to pick up a vandenplas metro engine, 72 bhp ,but not sure if the auto vp was running the same spec.

The biggest, most important difference with the Metro AP derivative is the oil cooler but yes the VP was fundamentally an MG engine