Farmboy
MEMBER
Middlebury, VT
This topic has been beaten and rebeaten, but at the end of day, for me, the operating cost of avgas is largely unaffordable. Therefore I run mogas, and to date with small continentals and Lycomings it’s not been any issue at all.
Years ago we tried to run mogas in my dads 180 Musketeer, and it did not like it I the summer at all. Went right back to 100LL.
So I’m not interested in those that swear the carbs are junk after using mogas, or there’s all these other issues, as I’ve just not seen it. I am a believer in another opinionated issue, which is I use MMO in my mogas. Lubrication is something I believe in wholly.
So in looking forward to a future airplane with a 180hp, I want/have to use mogas. If it were an off the shelf Titan 340, they offer it with low compression pistons making 170hp, to use mogas.
But I happened across the following statement today, which piqued my curiosity.
“......An alternative to running low compression pistons is to run a custom timing curve on electronic ignition. That's what I did. I run 90 octane(highest pump gas here) and have 2 maps. One for 100LL if I ever run it and want the bit of power back, and one for 90. The difference is 2 degrees retarded at WOT and 1 degree with the power back. It's a lot less HP loss than going to 8 or 7.5:1 pistons. And it's still a HP gain over stock at low power settings.
But our parallel valve 540s were certified on 91/96 to begin with.....”
So while he is using an o-540, the idea of using electronic ignition and different maps is something I had not heard of. We did it in bikes using power commander plug in boxes, but on an old tech aircraft engine?
Along this vein is the information from another builder/pilot that after chasing airflow, baffles and vents he solved his high temp issues by simply dialing back his timing a few degrees. Seems he had set it a touch too aggressive based on mfg recommendations. Which makes me think there’s even more reason to have a modern ignition system.
Anyone have solid info/data/experience with this?
Thanks,
Pb
Transmitted from my FlightPhone on fingers...
Years ago we tried to run mogas in my dads 180 Musketeer, and it did not like it I the summer at all. Went right back to 100LL.
So I’m not interested in those that swear the carbs are junk after using mogas, or there’s all these other issues, as I’ve just not seen it. I am a believer in another opinionated issue, which is I use MMO in my mogas. Lubrication is something I believe in wholly.
So in looking forward to a future airplane with a 180hp, I want/have to use mogas. If it were an off the shelf Titan 340, they offer it with low compression pistons making 170hp, to use mogas.
But I happened across the following statement today, which piqued my curiosity.
“......An alternative to running low compression pistons is to run a custom timing curve on electronic ignition. That's what I did. I run 90 octane(highest pump gas here) and have 2 maps. One for 100LL if I ever run it and want the bit of power back, and one for 90. The difference is 2 degrees retarded at WOT and 1 degree with the power back. It's a lot less HP loss than going to 8 or 7.5:1 pistons. And it's still a HP gain over stock at low power settings.
But our parallel valve 540s were certified on 91/96 to begin with.....”
So while he is using an o-540, the idea of using electronic ignition and different maps is something I had not heard of. We did it in bikes using power commander plug in boxes, but on an old tech aircraft engine?
Along this vein is the information from another builder/pilot that after chasing airflow, baffles and vents he solved his high temp issues by simply dialing back his timing a few degrees. Seems he had set it a touch too aggressive based on mfg recommendations. Which makes me think there’s even more reason to have a modern ignition system.
Anyone have solid info/data/experience with this?
Thanks,
Pb
Transmitted from my FlightPhone on fingers...