Hi guys...
I have A12A here and wondered what the deal is with them beside the 75mm bore..
Are they sort after...a good race engine...what they worth???
Also has an H85 round port head..
Thanks :)

The conrod takes a larger gudgeon pin, so it is somewhat useful when adapting larger 'A'-family pistons, the alternative is to simply machine your regular A12 conrods. This is the most common procedure as A12A conrods are not common.

The combustion chambers are of the performance shape and the cylinder takes a wet manifold. It also has the shared early and late bolt pattern for the inlet manifold. There is some commentary that the conrods are stronger but once again costs to strengthen regular A12 conrods are cheap enough not to warrant sourcing the not-so-plentiful A12A variant.

Not sought after, apart for their novelty factor their isn't much more appeal, perhaps an extra horsepower or so.

Engine is not worth much more than a regular A12 and some people would pay more because of it's novelty, I would.

A12A was a performance option of the A12: Larger bore, and was fitted to sedan/coupe while in the same market the A12 was fitted to wagon only. So all around a better engine than A12. About 5% better.

A12A came with:
* Different pistons & cylinder heads in different markets/years [edit:] all appear to be round port heads
* Dry manifold [edit:] Canada
* Wet manifold

A12A used the same Connecting Rods as A13 engine in B310. They feature the larger A14-size gudgeon pin, instead of the smaller pin of the earlier A12.

Thankx guys