In article , Pentti Kurkinen
writes

Napier did eventually accept Bristol assistance over the manufacture of
the sleeves (and the US milling machines that made it possible) - but
only after MAP told 'em to...


IIRC it was the other way round, Bristol did not want to reveal it's
manufacturing secrets to it's competitor, but was forced to do so...

I was going on the recollections of John Howlett, who was the MAP area
controller for the South. He stated that Bristol were 'mature enough to
offer any help they could give, but the offer wasn't taken up'. He
believed that Napier felt they had something to prove. He may have
formed an incorrect view, but he was at the heart of setting up the
facilities for engine production at the time.

Bristol's secret in successful production of the sleeves was BTW originally
"invented" by accident when a worker ground the final surface of sleeves
with an undressed grinding wheel.

It was fortunate that the 'sub-standard' sleeves were allowed to pass
quality control and get into the engine!


Cheers,

Dave

--
Dave Eadsforth