the early engines had a batch of bad "finger followers" that failed and took the whole engine with it this was the major black mark against the speed 6, most of the rebuilds were done as good will gestures by the factory.

The rest of the engine failures are not so easy to idenitify, the main rumor is that the original Al Melling design was changed by TVR to reduce costs. this subsiquently reduced resistance to abuse, most engines are thought to have failed to to improper warm up procedures and lack of maintenance. However there are reports that peope have religously followed the warm up proceedure full TVR services and engines have still failed.

FYI a full rebuild is about £6k drive in drive out

and this is the exact reason these cars are so cheap, 20k for a 2004 car offering those looks with that performance can't be found anywhere else, the downside is your looking at gambling 6k for a rebuild. Also there are reports of rebuilds needing rebuilds so even have a new engine is no long term guarantee...

basically this is a car you buy with your heart and not your head and if you don't have plenty of spare cash for maintenance then forget it.