Worried about 100LL

yeagert

Hey everyone. I bought a Piper Dakota last year and it seemed like right after I signed the paperwork, I was bombarded daily with news feed articles about the death of 100LL. Looking into it, it seems like engines such as the 540 used in the Dakota are not able to run on anything other than 100LL regardless of an STC (please tell me if I am wrong).
On top of that, the price of 100LL has gone up so much since I started flying 15 months ago. I’m beginning to worry that in a couple years, my Dakota and many other aircraft will be relegated to the junkyard. Does anyone have any good news or less dire takes on this issue?

-Jeff

Fgump52

According to GAMI, their G100UL will be able to work in all existing engines. Still waiting on the AML to include more engines and mass production though.

yeagert

Thanks Fgump. I had looked into Gami 100LL before but I never found good info that it would work fleet-wide. I’m glad to see that it should be a fleet-wide replacement for 100LL. I found a good FAQ on it for anyone finding this thread: https://gami.com/g100ul/GAMI_Q_and_A.pdf

empannin

Jeff,
In addition to GAMI there is also the Swift material. The transition is likely to be messy but in the end lead free 100 octane is going to be better for aviation. Once the lead is gone it opens up the possibilities for modern synthetic oils for less friction, better protection and longer life. New spark plug configs for longer life, lean burn and no plug fouling. No lead sludge in the crank for better and more consistent engine balance, etc

Better oils and no lead will mean less likelihood of hard deposits on the exhaust valves and reduced fouling of the rings - both of these drive low compression and premature cylinder replacement. Modern oils can also better protect the cams and internals from corrosion. Cam lifter and/or cam lobe damage are also drivers for early engine overhauls.

The reason these oils cannot be used today is the modern automotive synthetic will not keep lead in suspension and it settles out. There are some aviation synthetic compromises but we are not seeing the full benefit.

The other possibility is moving to closed loop control using an O2 sensor vs EGT. A wideband O2 sensor would enable closed loop fuel control and you could set Take off/climb/cruise/eco cruise settings. I actually have installed one in an RV10 an even with shorter lifetime due to lead fouling it is a great edition making it easy to manual set mixture levels.

Farther in the future I think we will see next generation cylinder designs that don't have to accommodate lead so can be better optimized for performance.

Resq5hvy

I cannot wait for 100UL.
Mobile 1 in all gasoline engines and some magic synthetic oil in the Diesel truck.