The prop I had before was a 72" Hartzel constant speed prop that was
recommended and sold through Glasair Corp and was recommended for 180/2-00 hp
Lyc. It didn't have a name, just serial numbers. Our new prop is a 72 inch
constant speed "Blended Foil" prop. My home base builder bolted one on his RV
9 and noted a 10 mph increase in cruise speed. I think my greater
performance was due to my plane not being completely stream lined in cruise and
with the added thrust this prop produces I had an increase in cruise speed
greater than 10 mph ranging between 15 to 20 mph. I have only recorded three
short flights with this new Blended Foil design and with the arrival of
spring I will be making more cross country flights and will report what I see.
As a side note, I placed my prop for sale in Trade A Plane and it
sold within two weeks to a Mooney driver. His prop hub was worn out and a
prop shop wanted close to $4,000 for a new hub and several thousand dollars
for two serviceable blades because one of his blades could no longer be
dressed. My old prop had less than 600 hours and after being inspected by a
prop shop, determined all it needed was inspection, paint and fresh seals and
grease. This Mooney driver would have had to pay $10,300 for a new prop and
was happy to find mine for half the price. Also, if you own a low time
prop in excellent condition like mine was, I was offered $3,000 by a prop
shop. Glasair supplies this new Blended Foil prop for $6,600. They installed
one on their factory Glasair Super 2S and noted a 7 mph increase.
In a message dated 3/4/2010 9:26:31 P.M. Eastern Standard Time,
dralle@matronics.com writes:
--> Glasair-List message posted by: Matt Dralle <dralle@matronics.com>
Nice report. What was the "old" prop you had?
Matt Dralle
RV-8 #82880 N998RV
http://www.mattsrv8.com Matt's Building Blog
Finishing Up...
At 03:27 PM 3/4/2010 Thursday, you wrote:
>We had another chance to test our new Hartzel blended foil prop on our
Glasair 2S FT-!0360 200 HP engine. We flew the plane with a light cross wind
this time and noted a shorter take off roll from the runway end threshold
to the hash marks. This time we noted that full take off RPM had settled
down to 2600 rpm and that the fluctuating RPM we had on our first flights may
have been due to either the prop purging itself of a little air or the oil
being a bit warmer. Our last prop required adjusting the hub stop to get
2750 rpm. We climbed to 6,500 feet at a 140 mph indicated airspeed and
noted this new prop provided a much higher rate of climb than our old prop did.
Once at altitude we flew West at 6,500 feet with 24 inches manifold
pressure, 2450 RPM and 50 degrees lean of peak for fifteen miles and recorded
GPS
ground cruise speeds of 214 mph in one direction and 204 mph on the return
course that averaged out to 209 mph and noted an increase of around 15 mph
over our old c!
ruise speed. This increase in air speed was a bit lower than the twenty
mph increase we noted at 3,000 feet. But this may have been do to slightly
warmer temperatures and saturated air from a rain system that was moving in.
The visibility for this flight was limited and no were near the crystal
clear air we had on our first two tests flights and that may have been the
cause. We also noted with our old prop that increasing the RPM over 2350 rpm
didn't add to the air speed, but increasing the rpm with the new blended
foil did increase airspeed all the way up to 2475 rpm. My guess for this is
that the new blended foil has far more bite at higher rpm's than our old
prop did. When the weather cooperates we will shoot for 8,500 feet on
hopefully a clear day.
>
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
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