A+ into Mk1 on original gearbox

A+ into Mk1 on original gearbox

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Discussion

NDT

Original Poster:

1,753 posts

263 months

Tuesday 17th June 2014
quotequote all
I've got an early mk1 and I'm generally trying to summon the motivation to start the rebuild or (more likely) pay someone else to do the body.

So rather than doing something useful about that I'm going to ask a random engine/gearbox question.

I have the standard mk1 850 and pudding stirrer gearbox.
I also have a 1275 turbo A+ engine and box - which wouldn't be going in with the turbo.

I don't need massive power (other cars are a VX220 turbo and a 335d so if I want to go quick I'll use them) but I think an 850 might drive me wild with its slowness.

2 options:
A+ engine and box, cut hole for rod change gear stick, or
A+ engine on Mk1 box, retain pudding stirrer for retro feel

what do we think?




Cooperman

4,428 posts

250 months

Tuesday 17th June 2014
quotequote all
An A+ engine will not fit onto an early gearbox due to the increased width across the big ends. The result is that the big ends hit the side of the gearbox casing.
It is possible to fettle the sides of the 'box until there is clearance, but it's a lot of work and care must be taken not to make the casing too thin.
I have done it with a 3-syncro early Cooper gearbox with an A+ block on top of it.

NDT

Original Poster:

1,753 posts

263 months

Tuesday 17th June 2014
quotequote all
Cooperman said:
An A+ engine will not fit onto an early gearbox due to the increased width across the big ends. The result is that the big ends hit the side of the gearbox casing.
It is possible to fettle the sides of the 'box until there is clearance, but it's a lot of work and care must be taken not to make the casing too thin.
I have done it with a 3-syncro early Cooper gearbox with an A+ block on top of it.
thanks, your posts are always informative.

I suppose I could try it with an 850...
...but then all the go-faster bits I've been amassing over the years would be redundant...

Cooperman

4,428 posts

250 months

Tuesday 17th June 2014
quotequote all
You could get a set of pre-A+ rods which have the same size big end journals.
It might be necessary to take a small amount from the sides of the gearbox, but not much if any.
The pre A+ rods are strong enough and will work fine.
A simple job really.

guru_1071

2,768 posts

234 months

Wednesday 18th June 2014
quotequote all
or, option three

keep your eye out for one of the 4 syncro 1128 cases that was factory supplied with a magic wand (from mk2 850s I think) - then any engine will fit on top of it and you will have a decent box under it.

it will look 'factory' from inside the car