---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Mon 10/27/03: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:49 AM - Question re hp percent (ThomasTholmes512@aol.com) 2. 10:30 AM - Re: Question re hp percent (flyv35b) 3. 07:48 PM - Re: Question re hp percent (ThomasTholmes512@aol.com) 4. 10:21 PM - Re: Question re hp percent (Steven Jackson) ________________________________ Message 1 _____________________________________ Time: 07:49:04 AM PST US From: ThomasTholmes512@aol.com Subject: TeamGrumman-List: Question re hp percent --> TeamGrumman-List message posted by: ThomasTholmes512@aol.com Folks, Is figuring the percentage of hp for a 150 hp AA1 as easy as looking it up in a P or C POH? Or Cheetah for that matter. Tom PS, I don't have any documentation w/me at the moment and I'm curious as to what rpm constitutes 75% hp. ________________________________ Message 2 _____________________________________ Time: 10:30:46 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: Question re hp percent --> TeamGrumman-List message posted by: "flyv35b" > Folks, > Is figuring the percentage of hp for a 150 hp AA1 as easy as looking it up in > a P or C POH? Or Cheetah for that matter. > Tom > PS, > I don't have any documentation w/me at the moment and I'm curious as to what > rpm constitutes 75% hp. No, it's not that easy. If your prop is pitched such that you can turn 2700 rpm at full throttle in level flight you probably can get a pretty reasonable approximation with the Cheetah performance info for the 59 in. pitch cruise prop. Since prop pitches vary considerably on the O-320 engine converted 2 place planes so does the % power even at the same rpm. The only really accurate way to determine % power would be to install a manifold pressure gauge and use that info along with rpm and OAT and Lycomings graphs in their operator's manual to accurately determine % power. With this info it doesn't make any difference what prop pitch you have you can determine % power even during climbs and descents. It is a useful instrument even though many people will say it is not needed with a fixed pitch prop. Cliff ----- Original Message ----- From: Subject: TeamGrumman-List: Question re hp percent > --> TeamGrumman-List message posted by: ThomasTholmes512@aol.com > > Folks, > Is figuring the percentage of hp for a 150 hp AA1 as easy as looking it up in > a P or C POH? Or Cheetah for that matter. > Tom > PS, > I don't have any documentation w/me at the moment and I'm curious as to what > rpm constitutes 75% hp. > > ________________________________ Message 3 _____________________________________ Time: 07:48:11 PM PST US From: ThomasTholmes512@aol.com Subject: Re: TeamGrumman-List: Question re hp percent --> TeamGrumman-List message posted by: ThomasTholmes512@aol.com I was afraid it would be a complicated issue. ;-) Tom ________________________________ Message 4 _____________________________________ Time: 10:21:04 PM PST US From: "Steven Jackson" Subject: RE: TeamGrumman-List: Question re hp percent --> TeamGrumman-List message posted by: "Steven Jackson" Get a copy of a Lycoming Operator's manual. I can't remember if you have a Tiger or one of the O-320 powered planes. But, inside the operators manual, besides all the other good gouge on the engine that's in there, there is also a performance chart that displays %horsepower for different configurations of fuel consumption, manifold pressure, and rpm. For my plane, 75% power is achieved at approximately 8000' density altitude, and tapers off as it gets higher Steven Jackson N1434R L22 Yucca Valley, CA -----Original Message----- From: owner-teamgrumman-list-server@matronics.com [mailto:owner-teamgrumman-list-server@matronics.com]On Behalf Of ThomasTholmes512@aol.com Subject: Re: TeamGrumman-List: Question re hp percent --> TeamGrumman-List message posted by: ThomasTholmes512@aol.com I was afraid it would be a complicated issue. ;-) Tom