Greg Copeland wrote:
On Thu, 29 Apr 2004 14:35:14 +0000, Ron Wanttaja wrote:

Some engines still require a touch of lead, especially just after a
rebuild. The guy who fixed my bad exhaust valve told me to fly exclusively
on 100LL for the first fifty hours, and then use 100 LL every fourth
fillup. 100LL has four times the lead as the old 80/87.

Thanks guys! A followup question.

Not trying to start pointing the age stick, but, leaded fuel was pretty
well on its way out when I kid. As such, I've not had much experience
with leaded fuel. Exactly what is the lead helping with?

It boosts octane and prevents (old) valves from microwelding to the (old)
valve seats. Modern valves and seats are made of stuff that doesn't
require lead.

There are limited (EPA approved) additives to boost the octane.

For more than you ever wanted to know about aviation fuel, see
http://www.chevron.com/prodserv/fuel.../aviationfuel/

--
Jim Pennino

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