Today's Message Index:
----------------------
1. 04:09 AM - Re: RV6-List Digest: 15 Msgs - 10/30/05 (Mark Taylor)
2. 05:21 AM - Re: fixed pitch prop question (Jim Wright)
3. 06:07 AM - Re: Re: brake leak? (art)
4. 06:19 AM - Re: fixed pitch prop question (Ken Dominy)
5. 08:25 AM - Re: fixed pitch prop question (Del Schneider)
6. 08:40 AM - Re: fixed pitch prop question (Jim Wright)
Message 1
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| Subject: | RE: RV6-List Digest: 15 Msgs - 10/30/05 |
--> RV6-List message posted by: "Mark Taylor" <mtaylo17@msn.com>
Ron,
This might sound a daft question, but is the plane completely finished, with
all the wheel fairings on and everything?
A friend of mine thought he had similar problems, with his plane being a
good 20mph slower and an inability to get full engine rpm in climb and
cruise. It turned out to be all the extra drag from no fairings!
Mark.
www.4sierratango.com
Time: 01:28:10 PM PST US
From: "Ron Carroll" <RonCarr@qwest.net>
Subject: RV6-List: fixed pitch prop question
My 6A has a history of low climb & low cruise RPM and high oil temps. My
mechanic, neighbors and friends have exhausted every means we can think of,
to no avail. I have a Lycoming O320-H2AD ( I really don't need negative
feedback regarding the choice of engines ), and had it overhauled 43 hours
ago. I hoped the overhaul would solve some of the problems, as it was in
pretty poor condition. The overhaul made absolutely no difference in either
RPM or high oil temp.
I changed to a larger oil cooler, no change. I then made a nice plenum for
the oil cooler, no change. I replaced the engine baffle seals, which made a
slight change in oil temp. These things, along with many other minor
things which were tried to satisfy various suggestions made by interested
onlookers.
The final thing my mechanic suggested was to have the Sensenich metal prop
re-pitched, and recommended the prop shop in Troutdale, Oregon. I flew the
plane, recorded some data I thought the shop would need in order to make the
proper change. I was disappointed to find that the prop shop didn't want
the data, they just need to know if I want better climb or cruise, I can't
have both. They can add or remove pitch, whatever I say I need or want.
They said that 1" pitch change would make about 25 to 35 RPM difference, so
how much more or less RPM do I want under what condition? What I need is
better climb (lower oil temp), and better cruise (?) at a higher RPM. The
engine may go faster, but the plane may not. This means poor fuel economy.
Broadly speaking, here are the performance figures I get:
RPM MP Throttle IAS Altitude Oil
2200 22.8 WOT climb 100 kts sea level 77C
2240 22.8 WOT climb 110 kts contin. climb 98C
2390 25.8 WOT 138 kts 3000' 100C
2410 25.7 WOT 142 kts 3000' 100C
2040 19.4 econ cruise 124 kts 3000' 100C
2000 18.9 " " 115 kts 3000' 99C
I know this is not very well arranged, nor is it very scientific, but its
what I have for now. My friends with RVs claim that I should get better
performance than this, both in air speed and RPM. My mechanic believes the
high oil temps are due to too much pitch. The engine can never get into the
160 HP range. "It is working too hard and creating heat, like driving your
car up hill in overdrive all the time.", he said.
My question is this: Has anyone re-pitched their prop to gain RPM? If so,
did it negatively affect your WOT cruise speed? Did it affect your oil
temp? Do I have any other options (again, don't mention the engine, I've
heard them all) ?
This thing should fly better than this!!!
Ron Carroll
Message 2
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| Subject: | fixed pitch prop question |
Maybe you misread the post. I got 10 mph higher with the cruise prop
(125mph) which you would expect. What was a little odd was I burned less
fuel per hour with the climb prop but lost 10 mph at the same rpm.
Overall I burned about the same amount of fuel on a trip with either
plane but the climb prop let me get off of grass strips better and climb
better. I would have thought the climb prop would have burned more fuel.
Sorry for the confusion.
Jim Wright RV-9A
Message 3
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What happens is the piston has to travel further when the pads are worn out
and this will cause the o-rings to leak, don't let them get that far down
and it won't be a problem.
-----Original Message-----
From: owner-rv6-list-server@matronics.com
[mailto:owner-rv6-list-server@matronics.com] On Behalf Of WPAerial@aol.com
Subject: RV6-List: Re: brake leak?
does anyone else have the brake caliber leak when the pads wares out?
as soon as the pad gets almost to the rivets the piston (hockey puck thing)
is close enough to full throw, the o-ring begins to leak. one good thing
about this is it tells me the brakes need replaced, but is it supposed to
happen?
jerry wilken
rv6a n699wp
370 hours
albany oregon
Message 4
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| Subject: | fixed pitch prop question |
Jim,Were you running WOT with the climb prop to get the same RPM (2350)? It would
seem to me that with a flatter pitch, the engine would not have to produce
as much power to turn the prop the same RPM, therefore, requiring less fuel
flow. Also, when considering that the airflow through the engine, don't forget
to consider the exhaust as well (is there a muffler?) Another possible related
story: I recently was chasing an intermittent miss on my O360 at low RPM
which seemed to disappear when the R PM incresed above 1400. Differential compression
checks showed normal, no leaks detected in the intake, normal timing,
good plugs, perfect mag drop, etc. I did a dynamic compression check (like
you do to a car engine) to see if the valves were opening normally and found a
single low cylinder( whcih ironically was one of the best differential checks)
I could not detect it with the engine readings, but the engine was not producing
the power it should because the intake valve
lifter was not fully expanded and the valve not fully opening allowing the cylinder to take in a complete charge. BTW it did not cure my low RPM intermittent miss which I believe has somthing to do with the very poor fuel distribution of the the carburated engine, and the fact I operate out of very high density altitudes at my home field.--- On Mon 10/31, Jim Wright jlwright@cox-internet.com wrote:From: Jim Wright [mailto: jlwright@cox-internet.com]To: rv6-list@matronics.comDate: Mon, 31 Oct 2005 07:20:39 -0600Subject: RE: RV6-List: fixed pitch prop question
Message 5
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| Subject: | fixed pitch prop question |
HTML_MESSAGE,J_CHICKENPOX_21 autolearn=no version=2.63
Hi Ron,
My RV6A O-360 started out with a Sensenich fixed 84" pitch prop. I later
switched to an 85". I have experienced high oil temp on climb out with both
props. I checked everything I could think of and found no reason. I ran
across an article telling of high engine temperatures when using Shell
15W50. As I was due for an oil change I filled with Shell W100. I now have
trouble getting the engine temp up under normal operating conditions and do
not worry about it on climb out. I live in Northern Canada and will more
than likely have to change for winter, I will try W80 and see what happens.
Give it a try,
Del Schneider
Prince George, BC.
C-GZVD
-----Original Message-----
From: owner-rv6-list-server@matronics.com
[mailto:owner-rv6-list-server@matronics.com]On Behalf Of Ron Carroll
Subject: RV6-List: fixed pitch prop question
My 6A has a history of low climb & low cruise RPM and high oil temps. My
mechanic, neighbors and friends have exhausted every means we can think of,
to no avail. I have a Lycoming O320-H2AD ( I really don't need negative
feedback regarding the choice of engines ), and had it overhauled 43 hours
ago. I hoped the overhaul would solve some of the problems, as it was in
pretty poor condition. The overhaul made absolutely no difference in either
RPM or high oil temp.
I changed to a larger oil cooler, no change. I then made a nice plenum
for the oil cooler, no change. I replaced the engine baffle seals, which
made a slight change in oil temp. These things, along with many other
minor things which were tried to satisfy various suggestions made by
interested onlookers.
The final thing my mechanic suggested was to have the Sensenich metal prop
re-pitched, and recommended the prop shop in Troutdale, Oregon. I flew the
plane, recorded some data I thought the shop would need in order to make the
proper change. I was disappointed to find that the prop shop didn't want
the data, they just need to know if I want better climb or cruise, I can't
have both. They can add or remove pitch, whatever I say I need or want.
They said that 1" pitch change would make about 25 to 35 RPM difference, so
how much more or less RPM do I want under what condition? What I need is
better climb (lower oil temp), and better cruise (?) at a higher RPM. The
engine may go faster, but the plane may not. This means poor fuel economy.
Broadly speaking, here are the performance figures I get:
RPM MP Throttle IAS Altitude Oil
2200 22.8 WOT climb 100 kts sea level 77C
2240 22.8 WOT climb 110 kts contin. climb 98C
2390 25.8 WOT 138 kts 3000' 100C
2410 25.7 WOT 142 kts 3000' 100C
2040 19.4 econ cruise 124 kts 3000' 100C
2000 18.9 " " 115 kts 3000' 99C
I know this is not very well arranged, nor is it very scientific, but its
what I have for now. My friends with RVs claim that I should get better
performance than this, both in air speed and RPM. My mechanic believes the
high oil temps are due to too much pitch. The engine can never get into the
160 HP range. "It is working too hard and creating heat, like driving your
car up hill in overdrive all the time.", he said.
My question is this: Has anyone re-pitched their prop to gain RPM? If
so, did it negatively affect your WOT cruise speed? Did it affect your oil
temp? Do I have any other options (again, don't mention the engine, I've
heard them all) ?
This thing should fly better than this!!!
Ron Carroll
Message 6
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| Subject: | fixed pitch prop question |
I was not at WOT at 2350 rpm. The engine still had more I just ran it
there because it the smoothest. It did have a muffler.
Jim Wright RV-9A 90919
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