Aero and Spree similarities

[Plooster]

I noticed that while looking through the service manuals that all the piston and cylinder specs are identical for the 1985 Aero and (all year) sprees.
If this is true, then could you buy a big bore kit for a 1985 Aero and put it in a spree. That would be cool.

[MySpree]

but are the mounting holes the same?

[maddog]

If the specs were the same then everyone would be doing it, better off doing an engine swap.

[noiseguy]

I noticed that while looking through the service manuals that all the piston and cylinder specs are identical for the 1985 Aero and (all year) sprees.
If this is true, then could you buy a big bore kit for a 1985 Aero and put it in a spree. That would be cool.

It's not quite that simple. On the Aero:
The piston/jug is slightly shorter (about 5mm),
The base gasket is different (larger ports, but close)
Exhaust ports from corner, not front (you'll need the Aero exhaust.)

Bolt circle and stroke are the same, and both have 10mm piston pins. Might fit, but no one's tried it yet. It's not a straight bolt-on, anyway.

And the Aero has a variator.