Stealth Pilot wrote:

I'm stuffed if I can see how the cold start will have ruined his
engine.
the traditional reason for warming an engine prior to flight is so
that the exhaust muffle is hot enough to deliver carby heat if needed
on climb out.

That's pretty funny. A preheat has so little affect on the temperature
of the exhaust muff that it isn't even a consideration. Within 10
seconds of engine start, the heat of the exhaust pipe will be at roughly
the same value whether the engine was started at 20 degrees F or 80
degrees F.

Matt