Raven wrote:
Are you sure?
TIO540 is turbocharged. AK1A seems to need 100LL.
Sorry, my mistake, the TIO hasn’t got the ticket (yet), the IO-540-AB1A5 is the one in the NA 182.
If I could I’d go UL91 only. No fouling and no need to fiddle the mixer on the ground.
Is it really true that if there is no lead, there is no need to lean on the ground?
Leaning on the ground is intended to increase the temperature inside the combustion chamber to enable. The chemical ( very long name ) that enables the lead to scavenge to operate, if you don’t reach the temperature lead condenses in the lower part of the combustion chamber.
When I was running two C152’s on a flying club we felt asking the students to lean on the taxi out / in was asking for trouble so the shut down was the Lycoming recommended run up that has been done to death on this forum, However it stopped the plug issues at 35-45 hours.
With UL fuel I can’t see any of the plug contamination issues arising as no lead will be present, however it will not stop contamination problems arising from glazed cylinders and worn valve guides.
Peter wrote:
Is it really true that if there is no lead, there is no need to lean on the ground?
From what I read it still is recommended, but the fouled plug issue is no longer present. We operate the O360 completely similar regardless whether there is 100LL or UL91 in the tanks.
“Is it really true that if there is no lead, there is no need to lean on the ground?”
Definitely not. There are many other solid state particles being produced when we have rich mixture.
The situation to fly unleaded is getting closer and closer.
Apparently Lycoming has approved the TB 20’s engines.
Does anyone have any experience converting AVGAS 100LL to UL91.
Back in the 80/87 days we used to set idle at 1000rpm with the switch to 100LL it was increased to 1200rpm probably for the reason listed above by A and C.
