Yup, this fuel burn makes sense to me. I normally lean mine (150 hp 0320 Rebel on 1800 amphibs) to 7.4 - 7.5 (I have a fuel flow gauge) at 2450 RPM and run just slightly rich of peak on my first cylinder to reach peak. This is at 2500 - 3500 altitude. However, I have noticed the higher you go, the higher RPM you need to maintain the same IAS and fuel burn goes down. Earlier this summer, I took a flight over to the interior of BC and had to climb and cruise at 9500 ASL to clear some mountains, and was cruising at 2500 RPM and burning only about 7.1 gph. I couldn't maintain my regular IAS at that altitude though, and never did calculate my true airspeed, but my GPS groundspeed was still up there, so I was satisfied. I was also fully loaded with fuel, wife, dog, luggage and camping gear.
Walter
-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:
murphy-rebel@dcsol.com]
On Behalf Of Wayne G. O'Shea
Sent: Wednesday, October 16, 2002 6:01 PM
To: murphy-rebel@dcsol.com
Subject: Re: Venting Moose Tanks
I was at 3500ASL going east and 6500 going west on the return. When it comes to leaning I usually just pull it out 'till it runs rough and push it back in about a 1/2" or so and leave it without paying too much attention to temps (EGT's somewhere around 1300*F). Good thing I didn't burn 10GPH or they would still be looking for me some where in amongst the rock/water/trees that cover the entire route!!!
The 7.8 USGPH fuel burn makes perfect sense to me. I used to burn no more than 5.5 GPH with my 100HP O-235 and I always had it wound right out to get some speed out of her and never bothered to lean as I was running 80/87 (If I powered back I could stretch out my 44 gallon tanks to 8 hours and still have reserve) . Add 50% power to get to 150 HP and I should be burning around around 8.25 GPH and I lean now to keep the plugs clean since I have to use 100LL, as 80/87 is no longer available from my supplier that fills my tank.
Wayne
----- Original Message -----
From: Legeorgen@aol.com (
Legeorgen@aol.com)
To: murphy-rebel@dcsol.com (
murphy-rebel@dcsol.com)
Sent: Wednesday, October 16, 2002 8:13 PM
Subject: Re: Venting Moose Tanks
Wayne,
That's a pretty good fuel burn (7.8 GPH) at 2500 RPM. That would place you at greater than 75% power, depending on what altitude you flew at, of course. My 0320 150 HP operation manual says you should be burning 10 GPH at that RPM. Where you leaning your mixture on the lean side of peak?
Bruce 357R
