Paul J. Adam wrote:
Packard cleaned up the castings, milled the mating faces approximately
flat (at least, compared to a metal-metal seal) and put a gasket between
them. I don't recall hearing tales of P-51s routinely or regularly falling
from the skies when their engines failed, nor of the Packard Spitfires
being execrated for unreliability (or, for that matter, lack of
horsepower).

A family friend, now departed, was a wrench-turner on (American)
Merlins during the war. He always said the Packard was easier to
work on, but did not take damage as well as, the RR version. His
reasoning was that, where RR might use (arbitrarily, as I can't recall
his exact words) 30 bolts spaced closely to attach an exhaust manifold,
Packard would use 20 spaced farther apart. He said that he saw
cases where Packard and Rolls-Royce engines would come back
with near-identical damage and the genuine article could still produce
power.


Jeff