Am just about to buy an mk indy with a blackbird engine, they're not that bad really, are they?

They were the dogs bollox years ago,just very old now.

Will still be a fast car,might be hard to find parts these days though

Seem to remember they had issues because in the bike the engine was using the bike frame as part of the engines strength,so once you remove from the bike frame and hang it from a cradle in a car chassis you have removed some of the strength that was designed to be there by Honda.
Iirc the block can twist if not mounted properly in a car,this then causes the crank bearings to be crushed/pushed against the crank and they then spin the crank bearings and destroy the engine.

Oil supply issues too, usually countered by baffled sump, Accusump, dry sump or some combination thereof. Likely to be more of a problem on track, maybe not such an issue for normal road use.
It'll still be a nippy car, particularly if injected.

I drove Pif's MK/Blackbird yesterday; It's not slow.

Oil surge is a known blackbird issue but on the road a sump baffle should be sufficient (all Pif's has). On track you'd want an Accusump as well.

Thanks chaps for replies😁

a mate had one in his Westfield and it was dry sumped, I seem to remember it being quite torqey for a bike engine
It went well enough..