"Paul J. Adam" wrote in message
...
In message , Ricardo
writes
Incidentally, a few sources have claimed that the Packard built Merlin,
whilst a superb engine, lacked the power levels of the Rolls Royce
version. This, it is claimed, was because the British kept secret the
composition of the phosphor-bronze bearings that they used in the engine.
No, I can't quote a source/s.

On the other hand, I heard - from "old factory hands" lecturing on
manufacturing technique at Highbury College in 1988 - that a big
difference between Packard and Rolls-Royce was in fitting the cylinder
head.

Rolls-Royce used a precision hand-scraped metal-to-metal fit. Very
effective, though extremely demanding in scarce skilled labour.
(Attempting to 'file flat' is a useful exercise for a trainee mechanical
engineer; it teaches a certain humility in demanding surface finishes)


When I started work as an engineering apprentice at ICI they still
sealed the main steam joints on the turbines in the power station
this way. It isnt the file flat that's so time consuming as the
scraping of the surface until its flat according to the reference
surface plate.

They now use a lapping machine and gasket and its no less
reliable and a LOT quicker, plus I doubt there are many
fitters around with the skills to scrape joints flat any more.

Keith





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