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With my BH5 kit on order, I've turned to the hotly debated question of which engine for my mission. I have a small 1,000' grass airstrip in the Cascade mountains (elev 2,000') on my ranch with tanks of 91 autogas that I'd like to use versus having a special tank of 100LL. I do 80% of my flying from my airstrip.
I watched Virgil's build YouTube videos and was intrigued about his adapting the 260HP IO-540-D4A5 to squeeze 290-300HP while burning 91 mogas. I've been chatting with Virgil about engine choices and he provided great feedback - most BH5 builders are putting in the IO-580 ("a true hot rod, high performance engine" - Virgil). I know several BH5 builders putting in the 300HP IO-540-L1C5. The challenge is finding cores for a rebuild versus writing a very big check for a new Lycoming. For rebuilds, there are IO-540-K cores available and Virgil is completing a rear sump airbox for it.
For my mission, I can get by with the smaller, lighter, much cheaper 260HP IO-540-D4A5 and add the EFII and other mods that Virgil describes to get 290HP. But I would love to hear what engines other BH5 builders selected and perhaps why? Please poke holes in my logic and bring up considerations I've overlooked.
Second question: autogas (with E10) vs mogas (ethanol free). I've done a lot of research on this question and read conflicting advice. When I read about ethanol separation at altitude or more water pooling in the tanks, I always go back to ... Rotax engines do just fine with autogas. I know a number of Rotax turbocharged experimental owners that fly from sea level to the mid-teens all 4 seasons with no issues. I understand the sealant and tubing issues that need addressed, but can I fly with 91E10 in my IO-540-D4A5 with EFII? And what would Ethanol free give me - more performance, higher safety margins, etc?
Thanks, John - first-time builder, first-time experimental flyer.
I watched Virgil's build YouTube videos and was intrigued about his adapting the 260HP IO-540-D4A5 to squeeze 290-300HP while burning 91 mogas. I've been chatting with Virgil about engine choices and he provided great feedback - most BH5 builders are putting in the IO-580 ("a true hot rod, high performance engine" - Virgil). I know several BH5 builders putting in the 300HP IO-540-L1C5. The challenge is finding cores for a rebuild versus writing a very big check for a new Lycoming. For rebuilds, there are IO-540-K cores available and Virgil is completing a rear sump airbox for it.
For my mission, I can get by with the smaller, lighter, much cheaper 260HP IO-540-D4A5 and add the EFII and other mods that Virgil describes to get 290HP. But I would love to hear what engines other BH5 builders selected and perhaps why? Please poke holes in my logic and bring up considerations I've overlooked.
Second question: autogas (with E10) vs mogas (ethanol free). I've done a lot of research on this question and read conflicting advice. When I read about ethanol separation at altitude or more water pooling in the tanks, I always go back to ... Rotax engines do just fine with autogas. I know a number of Rotax turbocharged experimental owners that fly from sea level to the mid-teens all 4 seasons with no issues. I understand the sealant and tubing issues that need addressed, but can I fly with 91E10 in my IO-540-D4A5 with EFII? And what would Ethanol free give me - more performance, higher safety margins, etc?
Thanks, John - first-time builder, first-time experimental flyer.
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