On Mon, 28 Jun 2004 10:39:31 -0500, Greg Copeland
wrote:

I agree, common sense says, we'll see a happier engine resulting from
better managed temps, but is there anything that supports what a "happier
engine" translates into?

Greg

This will be extremely difficult to quantify, because if you've read
all Deakin's columns, you will know that he feels that both Lycoming
and Continental have lost the ability to put together a long lasting
engine any longer. Also, there is a URL out there that describes the
problems the parallel head Lycoming 6 cylinder engine has in terms of
producing too much heat at the exhaust valve guide due to improper
original design back when they began installing hydraulic lifters.

This last piece of information is not from a Deaking column, it's from
two AP's who have done EXTENSIVE research on the problem of 6 cyl.
parallel valve Lycomings and why they can't seem to make TBO without
loosing compression because of excessive valve guide wear.

These guys traced it to the lack of oil flow to the valve guide, it's
that simple. Other engines that have MUCH more flow to the exhaust
valve guide do not suffer the same excessive valve guide wear.

See: http://egaa.home.mindspring.com/engine1.htm

What Deakin HAS said, and frequently, is that there are no engine
development engineers at Lycoming anymore. They've all retired.

Lycoming doesn't manufacture it's own parts anymore, they just
assemble what's sent them from outside sources.

But they still charge you plenty for them.

Corky Scott