Do you require 100LL?

[rv8ch]

The question is do you currently require 100LL for your flying RV, or will you require 100LL for your RV when it flies?

[Lars]

According to Superior, the parallel valve IO-360 that I bought from them for my RV-7 is rated for car gas. After experiencing the improvement that unleaded fuel made to the sludge... er, oil, in the crankcases of my motorcycles back when car gas made the switch, I'd be completely happy to never burn a liter of 100LL. Probably gonna be flying before that becomes practical though.

[jonbakerok]

You should have clarified who actually needs 100LL. If you're running 9.5:1 or better compression in a Lycoming, you need 100LL. If you're not, 95 (or even 93) octane unlead will work just fine. How about a new poll for people running better than 9.5:1 compression?

[allbee]

I would like to see a push for 95 unleaded gas for aviation available. That way we can see how many people actually will use that 100LL stuff.

I know when auto gas went unleaded there was the same type of discussions. The unleaded gas was slowly brought in and then the leaded was taken out all together. What I noticed after that was a much better engine, better technology. So get rid of that 100LL and bring on the better engine.

[Ron Lee]

Hence my YES vote for 100LL. Now whether I need the lead at its current level is unknown. Supposedly I need the octane to prevent detonation but even that may be unneeded IF I keep CHTs under some TBD value.

[osxuser]

Originally Posted by Ron Lee

Hence my YES vote for 100LL. Now whether I need the lead at its current level is unknown. Supposedly I need the octane to prevent detonation but even that may be unneeded IF I keep CHTs under some TBD value.

Yes, if you have a certified lyc, you need avgas.

[Pilottonny]

Here in Europe we have 95 and 98 octane car gas (some places may also have 91 octane).
So, if you check all your seals, O-rings and gaskets in the fuel system for compatibility with ethanol and design your fuel system correctly (f.e.: return line to the tank) running on car gas should not be an issue for an experimental. All the Rotax guys have been running car gas for many years now!

[Jamie]

Originally Posted by osxuser

Yes, if you have a certified lyc, you need avgas.

Having a certified Lycoming has nothing to do with it. Maybe I'm not getting your point? It's all about compression ratios with Lycomings and clones.

[Geico266]

Originally Posted by jonbakerok

You should have clarified who actually needs 100LL. If you're running 9.5:1 or better compression in a Lycoming, you need 100LL. If you're not, 95 (or even 93) octane unlead will work just fine. How about a new poll for people running better than 9.5:1 compression?

I was running 10.5 : 1 pistons in my 0-360 and used a mixture of 50/50 92 Octance car gas & 100LL. Worked great, and saved about $40 everytime I filled up. Mixing is an option also.

[rtry9a]

Isn't the real question whether air cooled engines can lubricate exhaust valves adequately w/o lead additives? Valve failures are already one of the sensitive areas with air cooling- going to nonleaded fuel might just make that problem worse. I believe auto engines use hardended valve seats to allow nonleaded fuel.