Bluelabel
Well Known Member
Wondering if anyone else has experienced this...
It's not consistent and I can't duplicate it.
Once in a while, when I switch tanks, it's almost as if the engine is without fuel for about a half a second. It comes right back, but at 160KTS, it will sure get your attention. Always scares the **** out of my wife and I. She won't watch when I switch tanks
On the 23 hours of flying to and from Oshkosh, it probably happened 3 times.
It does seem to always be when at altitude (=>10k)
I haven't documented the exact situations when it happens, because, to be honest, we are usually looking for clean underwear for a few minutes after it happens.
I thought I had the issue solved last year when I added an item to my runup checklist. "1800 rpm, toggle fuel tanks".
I always switch tanks very fast and smooth.
Andair duplex valve is installed per plans. I've checked for leaks. Nothing I can find.
Rich or lean has no effect.
I went over the issue with the Andair guys and went through inards of a valve at Oshkosh. Can't figure out what would cause it.
Only thing I can think is there is some situation causing an air bubble in the system. With our fuel system, we do have about 40 gallons/hour moving around the system at any time.
Anyone else had this issue?
It's not consistent and I can't duplicate it.
Once in a while, when I switch tanks, it's almost as if the engine is without fuel for about a half a second. It comes right back, but at 160KTS, it will sure get your attention. Always scares the **** out of my wife and I. She won't watch when I switch tanks
On the 23 hours of flying to and from Oshkosh, it probably happened 3 times.
It does seem to always be when at altitude (=>10k)
I haven't documented the exact situations when it happens, because, to be honest, we are usually looking for clean underwear for a few minutes after it happens.
I thought I had the issue solved last year when I added an item to my runup checklist. "1800 rpm, toggle fuel tanks".
I always switch tanks very fast and smooth.
Andair duplex valve is installed per plans. I've checked for leaks. Nothing I can find.
Rich or lean has no effect.
I went over the issue with the Andair guys and went through inards of a valve at Oshkosh. Can't figure out what would cause it.
Only thing I can think is there is some situation causing an air bubble in the system. With our fuel system, we do have about 40 gallons/hour moving around the system at any time.
Anyone else had this issue?