Does anyone have any figures on how much difference changing the
pitch of the prop
makes in cruise and climb?
Thanks,
Dan C
On Aug 16, 2008, at 10:19 AM, Ed Burkhead wrote:
John Cooper wrote:
>>>>>>>>>>>>>
Ed often refers to his “extreme climb prop”, a 7146. For any other
type, this is simply a climb prop. 7144 is extreme, or a seaplane
prop. The 7150, Ercoupe’s “standard” prop is a cruise prop in
anyone else’s world. Now, if the Ercoupe had significantly less
drag (and consequently higher cruise speed) then a higher pitch
might be warranted, but…
<<<<<<<<<<<<<
Notes from a lakeside campsite near Ely, Minnesota, just outside
the Boundary Waters Canoe Area.
I base that terminology (I invented) of calling teh 7146 an
"extreme climb prop" based on the "normal" Ercoupe terminology.
The 7146 gave my C-85 almost exactly the maximum allowed static rpm
of 2225.
I'd agree with John that the correct terminology for Coupes with
the C-85 should be:
7146 climb prop
7148 normal prop
7150 cruise prop
7152 extreme cruise prop only for light weight or extremely clean
Coupes (note that in a heavy plane, this prop may give both
terrible climb and terrible cruise).
John wrote:
>>>>>>>>>>>>>>>
There are a number of different type aircraft with C85 engines and
similar speed and drag characteristics. Ercoupes, Cessna 120/140,
Luscombe, Taylorcraft, the list goes on. With the exception of the
Ercoupe, they all call for a 7148 as the standard prop. There is
no reason why the Ercoupe would be any different.
<<<<<<<<<<<<<<<
Agreed.
The vacation is nice. More canoeing today. Back online normally
around Tuesday.
Ed
