Depends how its used. If the car has the capability of producing 250bhp, but spends most of its life being driven normally commuting, in traffic whatever, then its not going to wear out much quicker than usual.

Okay, was thinking about putting in an offer for Steve F's car but don't think I will bother now!!

If it had been an okay everyday drive without needing ££'s spent on it every few months would of seriously considered it.

it would be reliable it built right, but your looking at rebuilding ever 5000mile

as for when cold, aslong as you get a TB setup with a Cold start block on your fine, will run abit ruff for a 30'secs.

Should not have any problems at all, aslong as the engine is built right.

you have got to look at other things aswell around the engine, with 250+ your going to need a paddle cutch (bitch to drive around town) plus to get the most out of the engine you going to want to rasie the limiter, and good thing would be a dry sump.

did plan on doing this to MattC old car (now NovaGTE) but after found out it would need rebuilding ever 5000 changed are mind.

i would say 240'ish is the very very limits without silly rebuild times.

depends on how u got it to reach 250+ bhp...

2366cc (redrilled 2.2 underpiece), headwork, bigger valves in & outlets polished, tb's, Fast-DTA Aluminum Flywheel and some spray could still be relyable if done correctly and proffesional..

however u realy need to have respect for tuned engine's no flooring whilst cold etc..

example pic of a nice 2.3 16v with the above (exept spray)

I aggree with ed.

If you want a 250bhp reliable XE then you would be best running forged pistons and rods with 100bhp jet of nitrous oxide. Far easier to drive, more reliable, better fuel economy. As long as your not driving on gas all the time.

That would be near enough race spec. It would be un reliable and a pain in the arse to drive.

When the c20xe is tuned to this level, what is the reliability of the engine like? Does it require regular rebuilds or expensive services every few thousand miles? Is it a bitch to drive in the cold? Any other problems that could occur?

Lets say the engine has all uprated internals etc..