High speed prop
Posted: Sun Feb 19, 2012 11:30 am
Regarding the prop spinning 3300 RPM, I was very pleased with the Warnke
"Almost constant speed" wooden prop that I used on my KR-2 years ago,
turning about 3200 RPM max. Added benefit - it was very nice looking. Side
note regarding an old rumor - I have flown in rain, heavy at times, many
times behind good wooden props with no sign of damage. I think it's
possible the wooden prop versus rain problem may be from times past and
maybe sealers, coatings, and leading edge protection weren't quite as good
as they are now.
Mike
044SR
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ron
Shannon
Sent: Monday, December 11, 2006 9:32 AM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Engine Choices
Charlie,
I'm installing a Jabiru 3300 in 254R, to be certified as an amateur
built experimental (ABE) LSA. My reasons for selecting the 3300 were
conventional design, engineering simplicity, lightweight, good rep, etc.
Due to weight considerations, the only other serious contender for me
was the Rotax 912 ULS which, although it is a little lighter, also has
lower max HP, at least as rated. Although many good folk do swear by the
912's reliability, and they may well be right, it is a more complex
design (dual carbs, gearbox, plumbing, outboard oil sump, etc.)
There has been considerable discussion on this list about issues with
prop selection with the Jabiru 3300, due to its relatively high tip
speeds at its max power, direct drive 3300 RPM. While I don't want to
reopen that debate, at Oshkosh '06 I did find the folks from Legend
Aircraft were very happy with a Sensenich W68CK38 wood prop on their
3300-powered LSA Cub knockoff. After discussing the issues with
Sensenich engineers at length, I decided to get a W68CK38G (with
composite covering) for 254R. Though it's not flying yet, I'm expecting
it will perform well.
BTW, when comparing engine weights, be sure you're comparing apples to
apples, i.e., weight with all accessories -- or not. The 3300 with
starter, alternator, regulator & complete exhaust system, etc., is about
175 lbs.
Ron
254R
http://n254mr.com
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
"Almost constant speed" wooden prop that I used on my KR-2 years ago,
turning about 3200 RPM max. Added benefit - it was very nice looking. Side
note regarding an old rumor - I have flown in rain, heavy at times, many
times behind good wooden props with no sign of damage. I think it's
possible the wooden prop versus rain problem may be from times past and
maybe sealers, coatings, and leading edge protection weren't quite as good
as they are now.
Mike
044SR
-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ron
Shannon
Sent: Monday, December 11, 2006 9:32 AM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Engine Choices
Charlie,
I'm installing a Jabiru 3300 in 254R, to be certified as an amateur
built experimental (ABE) LSA. My reasons for selecting the 3300 were
conventional design, engineering simplicity, lightweight, good rep, etc.
Due to weight considerations, the only other serious contender for me
was the Rotax 912 ULS which, although it is a little lighter, also has
lower max HP, at least as rated. Although many good folk do swear by the
912's reliability, and they may well be right, it is a more complex
design (dual carbs, gearbox, plumbing, outboard oil sump, etc.)
There has been considerable discussion on this list about issues with
prop selection with the Jabiru 3300, due to its relatively high tip
speeds at its max power, direct drive 3300 RPM. While I don't want to
reopen that debate, at Oshkosh '06 I did find the folks from Legend
Aircraft were very happy with a Sensenich W68CK38 wood prop on their
3300-powered LSA Cub knockoff. After discussing the issues with
Sensenich engineers at length, I decided to get a W68CK38G (with
composite covering) for 254R. Though it's not flying yet, I'm expecting
it will perform well.
BTW, when comparing engine weights, be sure you're comparing apples to
apples, i.e., weight with all accessories -- or not. The 3300 with
starter, alternator, regulator & complete exhaust system, etc., is about
175 lbs.
Ron
254R
http://n254mr.com
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------
-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------