The Murphy Builders Site

Hi Keith !

I'm with Ken ! I don't have the fancy electronic ignition,
just stock mags & carb, on my O-320E2D. It burns 8 gph
at 2,450 rpm, and is very happy there. On a previous Ramble,
I ran it at 2,350 - it burns about 1 gph less, and is reasonably
happy there, but 2,250 or 2,100 are not so good ... it seems
rough, and get harder to start. There's no question that the
old Continental O-300 6 cyl burns less fuel....

On the subject of fuel .... On Ramble 2007, we flew out to
the West Coast, and back to Oshkosh. This involved a lot
of flying in 95 - 100 + F. temperatures, through the mountains,
from airports near 4,000 ft. ASL. We all carried 2 passengers,
and camping gear. I put $2,630 worth of 100 LL in my O-320
(those were lower prices back then ...). The Rebel with the
80 hp. Rotax 912 used about $880 worth of mogas, the Rebel
with the 100 hp. Rotax 912 used about $1,100 worth, and
I believe the Rebel with the Subaru 2.2L used about $1,200 - $1,300
worth of mogas .... SO -- we all got there, and it cost me over
DOUBLE the gas.... Yes, I could carry a bit more weight, and
climb a bit faster sometimes (although the Subaru wanted to
pass me !), and cruise a bit faster ....

My NEXT Rebel will have a 100 hp. Rotax 912, and might
go on 1500 Murphy amphib floats....

I think Tom summed it up quite nicely - he said (approximately):
"I chose the Rotax 912 because I couldn't think of anywhere I
wanted to go that quickly that was worth the extra fuel ! "