I've been following the development of Diamond-Like Coatings (DLC's) for a
decade of so. These are vapor deposited coatings of carbon in diamond
crystal form applied directly to engine parts. The motorcycle racers have
exploited this technology for about an 8% increase in HP through reduction
in internal friction.

The stuff works on any internal surface where friction and wear is a
problem. Lycoming cams and mushroom tappets seem like a natural aplication.
The costs have come down to where a few hundred dollars of coating work is
enough for an engine. However, I haven't heard of the technology being
applied to aviation piston engines.

Bill D


wrote in message
ups.com...
On Apr 20, 5:42 pm, Mark Hickey wrote:

A truly outstanding article, but I tripped over...

Full-flow oil filtration was the hands-down
winner, reducing some types of wear by as much as 600%.
----------------------------------------------------------------------------------------------------------------
I can type over 100wpm. Oft times that's faster than I can
think :-) (I was trying to type '...as much as 60%.')

A few of the actual figures cited were 66% for wrist-pin wear, 50% for
crankshaft wear, 19% reduction of cylinder wall wear, 52% for piston
ring wear...

Some years ago I spoke with a fellow who retired from Fords that
remembered the project. He said it actually started in 1940 but was
put aside when the engineers were assigned to war-time projects. It
was taken up again following WWII but the test engines were only run
on a 9-to-5 basis, five days a week.

-R.S.Hoover