"Mike Spera" wrote in message
...


I've been more cautious about rapid heating up of engines since I
unfortunately split the engine block of my Jaguar XJ6 4.2 litre that I
conclude was caused by immediate rapid driving from -5c being late for an
appointment. Guess that expensive incident will always stay in my mind...


My guess would be that the very cold temps caused the block to split due
to the coolant freezing over night. If it was -5C when you started it,
chances are it was much colder at some point in the evening.

Common in the upper Midwestern US was to see 70's era cars blow out freeze
plugs and/or crack blocks by running no (or too weak) antifreeze. A cold
start and immediate run up to high speed should not cause catastrophic
failure of a block. Being a Jag, it may have had a badly cast block since
new. Their QC ain't the best.

Good Luck,
Mike

Mike, the coolant was at the correct winter dilution so I don't think
freezing was a contributory factor. More likely sloppy engineering standards
which similarly and sadly led to the downfall of the UK's motorcycle
industry, I know I owned many UK produced bikes. At least those industries
didn't manufacture aero engines.
Cheers,
Mike