Re: COZY: Fuel Grade Requirements for Lycoming Engines

Marc J. Zeitlin

Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

Marc J. Zeitlin                      marc_zeitlin@...
Copyright © 2022                     Burnside Aerospace

Join to automatically receive all group messages.