Today's Message Index:
----------------------
1. 05:40 AM - Re: Corvair thoughts (del magsam)
2. 05:55 AM - Re: Corvair thoughts (John McNarry)
3. 06:04 AM - Cover for Wood Prop (Dick and Marge Gillespie)
4. 06:47 AM - Re: I just gotta share this..... (Alex Sloan)
5. 08:09 AM - driving Miss Daisy (Oscar Zuniga)
6. 08:13 AM - Re: Cover for Wood Prop (DJ Vegh)
7. 09:11 AM - Re: Corvair thoughts (John Ford)
8. 09:17 AM - Re: Cover for Wood Prop (John Ford)
9. 09:24 AM - Re: Corvair thoughts (DJ Vegh)
10. 02:52 PM - Re: Corvair thoughts (Jim Ash)
11. 03:05 PM - Re: Cover for Wood Prop (Jim Ash)
12. 04:41 PM - Pedals vs Rudder Bar (Isablcorky@aol.com)
Message 1
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| Subject: | Re: Corvair thoughts |
--> Pietenpol-List message posted by: del magsam <farmerdel@rocketmail.com>
Thanks for sharing your Broken Crank experience, I'm
open to what everybody's experience has been, this is
the second broken crank I've heard of, thats not very
many in 43 yrs of flying and driving with a corvair.
My neighbor used to race corvairs in the 60s. He said
that he's broken everypart of the engine, but never a
crankshaft. And since I am derating my vair to about
1/2 of the horses he pushed out, and never abusing it
to the point that the racers do, I feel assured that
the crank is not a weak point. and has been well
tested.
Del
--- Jim Ash <ashcan@earthlink.net> wrote:
> --> Pietenpol-List message posted by: Jim Ash
> <ashcan@earthlink.net>
>
> Ken -
>
> If the crank were just a chunk of straight steel, I
> probably wouldn't care
> where the thrust bearing is. Pushing the thrust line
> through 24(?) 90
> degree bends is specifically the scariest part of
> the thrust-line thing for me.
>
> I broke a Corvair crank in two in one of my cars
> maybe 8 years ago (on the
> way home from the airport after playing with the
> Cub, no less). It can be
> done, so don't try to lie to yourself when the
> 'experts' tell you how
> strong it is and it can never happen. Nobody is
> forging factory new Corvair
> cranks, and you probably don't know the history of
> the one you have, to
> know if it was abused somehow. You could magnaflux
> it or do some other
> kinds of tests, but I honestly don't know if they
> could have predicted that
> crank failure. Unfortunately, I didn't save the old
> crank as proof. It
> cracked across one of the crank lobes, the one right
> next to the #4
> bearing. If you think about it, as you go up the
> crank from the #1 cylinder
> to the #6, each one adds successively more torque to
> the crank, so that
> last lobe is getting pushed around by all 6
> cylinders, while the first lobe
> only has to turn the distributor/oil pump and the
> fuel pump eccentric; big
> whoop.
>
> To its credit, the engine was still running with the
> broken crank when I
> shut it down. I had a sudden nasty vibration and I
> knew something was wrong
> deep inside, but I made it maybe 2-3 miles before I
> pulled into a gas
> station and called for a tow. The first three mains
> held the bulk of the
> crank in place and aligned, and #4 held the last
> chunk and the torque
> converter, which I found more surprising, given
> there weren't at least two
> bearings to support it, and the #4 isn't flanged. I
> suspect the drive shaft
> and gyroscopic effect helped with the alighment. The
> crack remained aligned
> well enough to continue to 'push' the output section
> of crank around. I was
> amazed when I popped the top cover. The case around
> the bearings wasn't
> even destroyed, more remarkably. It runs in one of
> my cars today, although
> I wouldn't have it in an airplane.
>
> I think William experimented with driving a prop
> from the pulley side of
> the crank instead of the flywheel side, but I don't
> know the mechanics of
> how he set it up.
>
> Jim Ash
>
>
> At 6/27/2003 10:48 PM -0500, you wrote:
> >--> Pietenpol-List message posted by: "Ken
> Anderson" <piet4ken@mindspring.com>
> >
> >Years ago I was looking into using a VW engine in a
> different application. I
> >decided to pass.
> >I too had concerns with the thrust going through
> the crankshaft to the far
> >end .
> >Not just that but the thrust forces have to make 90
> degree turns thtough
> >each rod throw too
> >I talked to the Great Planes folks that sell
> converted VW engines for
> >aircraft and said that it was not an issue. The
> crank is forged and can take
> >the load.
> >Great Planes is now selling a thrust unit / prop
> extension (1:1 ) that
> >attaches to the flywheel end of a VW engine to take
> the thrust loads.
> >Limbach engines are loosely based on VW. Where is
> the thrust bearing? Subaru
> >direct drive applications where is the thrust
> bearing? Maybe someone has an
> >answer.
> >
> >Ken
> ...
>
>
>
> Contributions
> any other
> Forums.
>
> latest messages.
> List members.
>
> http://www.matronics.com/subscription
> http://www.matronics.com/FAQ/Pietenpol-List.htm
>
Digests:http://www.matronics.com/digest/pietenpol-list
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>
>
>
>
=====
Del-New Richmond, Wi
"farmerdel@rocketmail.com"
__________________________________
Message 2
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| Subject: | Corvair thoughts |
--> Pietenpol-List message posted by: "John McNarry" <jmcnarry@escape.ca>
Very interesting observations Ken
The Ford A or B engines as used in Pietenpols have the output from the
flywheel end and to boot the thrust flange is at the prop end. The output
bearing is considerably longer than the rest as well. ( Should be able to
handle P factor loads from me doing severe aerobatics. Big Grin ) My engine
is a B with the crank drilled for oiling. The bearing sizes work out very
close to those in an o-200 Continental. Perhaps the Ford engines aren't so
foolish after all?
John
-----Original Message-----
From: owner-pietenpol-list-server@matronics.com
[mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Jim Ash
Subject: Re: Pietenpol-List: Corvair thoughts
--> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
Ken -
If the crank were just a chunk of straight steel, I probably wouldn't care
where the thrust bearing is. Pushing the thrust line through 24(?) 90
degree bends is specifically the scariest part of the thrust-line thing for
me.
I broke a Corvair crank in two in one of my cars maybe 8 years ago (on the
way home from the airport after playing with the Cub, no less). It can be
done, so don't try to lie to yourself when the 'experts' tell you how
strong it is and it can never happen. Nobody is forging factory new Corvair
cranks, and you probably don't know the history of the one you have, to
know if it was abused somehow. You could magnaflux it or do some other
kinds of tests, but I honestly don't know if they could have predicted that
crank failure. Unfortunately, I didn't save the old crank as proof. It
cracked across one of the crank lobes, the one right next to the #4
bearing. If you think about it, as you go up the crank from the #1 cylinder
to the #6, each one adds successively more torque to the crank, so that
last lobe is getting pushed around by all 6 cylinders, while the first lobe
only has to turn the distributor/oil pump and the fuel pump eccentric; big
whoop.
To its credit, the engine was still running with the broken crank when I
shut it down. I had a sudden nasty vibration and I knew something was wrong
deep inside, but I made it maybe 2-3 miles before I pulled into a gas
station and called for a tow. The first three mains held the bulk of the
crank in place and aligned, and #4 held the last chunk and the torque
converter, which I found more surprising, given there weren't at least two
bearings to support it, and the #4 isn't flanged. I suspect the drive shaft
and gyroscopic effect helped with the alighment. The crack remained aligned
well enough to continue to 'push' the output section of crank around. I was
amazed when I popped the top cover. The case around the bearings wasn't
even destroyed, more remarkably. It runs in one of my cars today, although
I wouldn't have it in an airplane.
I think William experimented with driving a prop from the pulley side of
the crank instead of the flywheel side, but I don't know the mechanics of
how he set it up.
Jim Ash
At 6/27/2003 10:48 PM -0500, you wrote:
>--> Pietenpol-List message posted by: "Ken Anderson"
<piet4ken@mindspring.com>
>
>Years ago I was looking into using a VW engine in a different application.
I
>decided to pass.
>I too had concerns with the thrust going through the crankshaft to the far
>end .
>Not just that but the thrust forces have to make 90 degree turns thtough
>each rod throw too
>I talked to the Great Planes folks that sell converted VW engines for
>aircraft and said that it was not an issue. The crank is forged and can
take
>the load.
>Great Planes is now selling a thrust unit / prop extension (1:1 ) that
>attaches to the flywheel end of a VW engine to take the thrust loads.
>Limbach engines are loosely based on VW. Where is the thrust bearing?
Subaru
>direct drive applications where is the thrust bearing? Maybe someone has an
>answer.
>
>Ken
...
Message 3
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| Subject: | Cover for Wood Prop |
--> Pietenpol-List message posted by: "Dick and Marge Gillespie" <margdick@peganet.com>
Since my newly completed GN-1 may have to live in the Fla. sun and rain for awhile,
I would like to protect this nice new wooden prop as best I can. What would
be the best material to make a cover out of without cooking it (the prop)?
DickG. in Ft.Myers
Message 4
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| Subject: | Re: I just gotta share this..... |
--> Pietenpol-List message posted by: "Alex Sloan" <alexms1@bellsouth.net>
Congratulations to Jim in Plano,
I have been there twice and I fully know the feelings.
Alex Sloan
----- Original Message -----
From: "Jim Markle" <jim_markle@mindspring.com>
Subject: Pietenpol-List: I just gotta share this.....
> --> Pietenpol-List message posted by: "Jim Markle"
<jim_markle@mindspring.com>
>
> I've got to tell you all about my recent "progress".....
>
> Up until a couple weeks ago I had only the center section (90%) done, all
> ribs, most of the wing hardware, all the tail wood/hardware done and that
> was it. So basically just the center section, tail and ribs.....
>
> Been working on wing design options (I've opted for an I-beam design) and
> was about to start cutting, scarfing and assembling the spars/ribs......
>
> I now have all the above AND the fuse (well, the fuse needs a little work,
> it's probably 95% ready at this point), tailwheel, split axle gear
(damaged
> but maybe 50% usable), ALL required turnbuckles and nuts/bolts AND
remaining
> hardware (I probably won't need to weld much more except some (maybe I'll
> braze instead?....sorry, just kidding) on the landing gear, A65 eye brows
> and some cowling and many many misc parts. And plenty of Spruce for all
the
> fiddly odds and ends remaining.
>
> Basically just need to build the wings and landing gear and start on the
95%
> they say you have remaining when you get to the 95% point.
>
> This thing is starting to be a REAL airplane........and yes, I know, my
> percentages are probably WAY off but as this thing sits, it's getting a
LOT
> closer!
>
> "My" fuse looks incredible even though it's just propped up on a sawhorse
> gear. But my center section is on the plane and the tail is sitting on a
> real tail wheel....I always have to turn up the radio so the neighbors
> wouldn't hear my airplane sounds....
>
> And what I don't need (from what Duane gave me, thank you Duane...) is (so
> far) going to be used on 3 other Air Campers being built in the area. Is
> that neat, or what?
>
> You're probably the only group in existense that would understand how
> exciting this is.......
>
> And yes, Corky, I'm counting the days too..... (29 to go)
>
> Jim in Plano
> My build log:
http://www.mykitplane.com/Planes/buildLogReport.cfm?PlaneID=52
>
>
Message 5
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| Subject: | driving Miss Daisy |
--> Pietenpol-List message posted by: "Oscar Zuniga" <taildrags@hotmail.com>
To Jim (and the others with reservations about the Corvair)- just use
something else if you aren't comfortable with the thrust bearing or anything
else about it. Lots of hours have been flown behind Corvairs in Pietenpols,
but if it's not for you- there are plenty of other options! This is about
fun flying, and it ain't fun if you're sweating bullets every time you shout
'clear'. But if you want to seriously investigate the option, why not join
the CorvAIRCRAFT list and get your questions answered or discussed? Go to
http://www.krnet.org/corvaircraft_inst.html for info on joining or listening
in.
And to Del's response to your concern about your wife's ability to get into
the front cockpit (he wrote-
>It is more fun to watch your wife climb in, than for
>her to crawl in. (per watching Mike Cuys girlfriend on
>his video)
Think of it this way- with the Pietenpol you get the chance to check out
plenty of female -er- 'seat cushions' if you give rides ;o)
Adding a door to the front cockpit makes it much more graceful. Take a look
at John Dilatush's setup at http://www.flysquirrel.net/piets/P6210011.JPG to
give you an idea of how much easier it is without the cabane X-bracing and
with an added door.
And welcome to the lowest, slowest, oldest bunch of homebuilders on the Net.
Anybody who likes a Piet has to be OK...
Oscar Zuniga
San Antonio, TX
Message 6
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| Subject: | Re: Cover for Wood Prop |
--> Pietenpol-List message posted by: "DJ Vegh" <aircamper@imagedv.com>
My Seadoo cover is made from a very heavy canvas type of material. It
takes the Arizona sun just fine....... but we hardly get rain here.
Maybe try a neoprene material... like they use for wetsuits. Get white if
you can to help reflect the sun's heat.... neoprene will keep the moisture
out... It can be found at marine upholstery stores....
DJ Vegh
N74DV
Mesa, AZ
www.imagedv.com/aircamper
-
----- Original Message -----
From: "Dick and Marge Gillespie" <margdick@peganet.com>
Subject: Pietenpol-List: Cover for Wood Prop
> --> Pietenpol-List message posted by: "Dick and Marge Gillespie"
<margdick@peganet.com>
>
> Since my newly completed GN-1 may have to live in the Fla. sun and rain
for awhile, I would like to protect this nice new wooden prop as best I
can. What would be the best material to make a cover out of without cooking
it (the prop)?
>
> DickG. in Ft.Myers
>
>
Message 7
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| Subject: | Re: Corvair thoughts |
--> Pietenpol-List message posted by: "John Ford" <Jford@indstate.edu>
Jim,
Keep in mind that the crank on an aircraft never has an instantaneous torsional
load of the magnitude it would get from a popped clutch or even mildly aggressive
driving (such as pulling out on the highway with traffic). The load is relatively
constant and smoothly applied, even with a decent sized prop. I am
of the opinion also that the thrust bearing would be much more of an issue in
a heavier and higher performance aircraft than pulling what isn't much more than
a big kite! Of course, I may be completely wrong for the first time ever in
my life... ;-)
John
John Ford
jford@indstate.edu
812-237-8542
>>> ashcan@earthlink.net Friday, June 27, 2003 11:45:36 PM >>>
--> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
Ken -
If the crank were just a chunk of straight steel, I probably wouldn't care
where the thrust bearing is. Pushing the thrust line through 24(?) 90
degree bends is specifically the scariest part of the thrust-line thing for me.
I broke a Corvair crank in two in one of my cars maybe 8 years ago (on the
way home from the airport after playing with the Cub, no less). It can be
done, so don't try to lie to yourself when the 'experts' tell you how
strong it is and it can never happen. Nobody is forging factory new Corvair
cranks, and you probably don't know the history of the one you have, to
know if it was abused somehow. You could magnaflux it or do some other
kinds of tests, but I honestly don't know if they could have predicted that
crank failure. Unfortunately, I didn't save the old crank as proof. It
cracked across one of the crank lobes, the one right next to the #4
bearing. If you think about it, as you go up the crank from the #1 cylinder
to the #6, each one adds successively more torque to the crank, so that
last lobe is getting pushed around by all 6 cylinders, while the first lobe
only has to turn the distributor/oil pump and the fuel pump eccentric; big
whoop.
To its credit, the engine was still running with the broken crank when I
shut it down. I had a sudden nasty vibration and I knew something was wrong
deep inside, but I made it maybe 2-3 miles before I pulled into a gas
station and called for a tow. The first three mains held the bulk of the
crank in place and aligned, and #4 held the last chunk and the torque
converter, which I found more surprising, given there weren't at least two
bearings to support it, and the #4 isn't flanged. I suspect the drive shaft
and gyroscopic effect helped with the alighment. The crack remained aligned
well enough to continue to 'push' the output section of crank around. I was
amazed when I popped the top cover. The case around the bearings wasn't
even destroyed, more remarkably. It runs in one of my cars today, although
I wouldn't have it in an airplane.
I think William experimented with driving a prop from the pulley side of
the crank instead of the flywheel side, but I don't know the mechanics of
how he set it up.
Jim Ash
At 6/27/2003 10:48 PM -0500, you wrote:
>--> Pietenpol-List message posted by: "Ken Anderson" <piet4ken@mindspring.com>
>
>Years ago I was looking into using a VW engine in a different application. I
>decided to pass.
>I too had concerns with the thrust going through the crankshaft to the far
>end .
>Not just that but the thrust forces have to make 90 degree turns thtough
>each rod throw too
>I talked to the Great Planes folks that sell converted VW engines for
>aircraft and said that it was not an issue. The crank is forged and can take
>the load.
>Great Planes is now selling a thrust unit / prop extension (1:1 ) that
>attaches to the flywheel end of a VW engine to take the thrust loads.
>Limbach engines are loosely based on VW. Where is the thrust bearing? Subaru
>direct drive applications where is the thrust bearing? Maybe someone has an
>answer.
>
>Ken
...
Message 8
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| Subject: | Re: Cover for Wood Prop |
--> Pietenpol-List message posted by: "John Ford" <Jford@indstate.edu>
I would imagine you also need to consider something loose fitting that will allow
some airflow to deal with any condensation issues. Florida air seems to be
mostly water...
John
John Ford
jford@indstate.edu
812-237-8542
>>> aircamper@imagedv.com Saturday, June 28, 2003 10:12:59 AM >>>
--> Pietenpol-List message posted by: "DJ Vegh" <aircamper@imagedv.com>
My Seadoo cover is made from a very heavy canvas type of material. It
takes the Arizona sun just fine....... but we hardly get rain here.
Maybe try a neoprene material... like they use for wetsuits. Get white if
you can to help reflect the sun's heat.... neoprene will keep the moisture
out... It can be found at marine upholstery stores....
DJ Vegh
N74DV
Mesa, AZ
www.imagedv.com/aircamper
-
----- Original Message -----
From: "Dick and Marge Gillespie" <margdick@peganet.com>
Subject: Pietenpol-List: Cover for Wood Prop
> --> Pietenpol-List message posted by: "Dick and Marge Gillespie"
<margdick@peganet.com>
>
> Since my newly completed GN-1 may have to live in the Fla. sun and rain
for awhile, I would like to protect this nice new wooden prop as best I
can. What would be the best material to make a cover out of without cooking
it (the prop)?
>
> DickG. in Ft.Myers
>
>
Message 9
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| Subject: | Re: Corvair thoughts |
--> Pietenpol-List message posted by: "DJ Vegh" <aircamper@imagedv.com>
I concur.... a car pulling hard through the gears up to redline creates
alot more torsional stress/variances than a 68" prop running smoothly at
about 3300 rpm..... plus alot of manual tranny drivers like to
downshift/engine brake when slowing.... putting negative torque on that
crank... this is stuff you just don't get in the air.
I really feel a 'Vair in a plane like the Piet is the way to go.... but
you gotta build the engine yourself and get intimate with it.... know it's
every bolt & piece.
DJ Vegh
N74DV
Mesa, AZ
www.imagedv.com/aircamper
-
----- Original Message -----
From: "John Ford" <Jford@indstate.edu>
Subject: Re: Pietenpol-List: Corvair thoughts
> --> Pietenpol-List message posted by: "John Ford" <Jford@indstate.edu>
>
> Jim,
>
> Keep in mind that the crank on an aircraft never has an instantaneous
torsional load of the magnitude it would get from a popped clutch or even
mildly aggressive driving (such as pulling out on the highway with traffic).
The load is relatively constant and smoothly applied, even with a decent
sized prop. I am of the opinion also that the thrust bearing would be much
more of an issue in a heavier and higher performance aircraft than pulling
what isn't much more than a big kite! Of course, I may be completely wrong
for the first time ever in my life... ;-)
>
> John
>
> John Ford
> jford@indstate.edu
> 812-237-8542
>
>
> >>> ashcan@earthlink.net Friday, June 27, 2003 11:45:36 PM >>>
> --> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
>
> Ken -
>
> If the crank were just a chunk of straight steel, I probably wouldn't care
> where the thrust bearing is. Pushing the thrust line through 24(?) 90
> degree bends is specifically the scariest part of the thrust-line thing
for me.
>
> I broke a Corvair crank in two in one of my cars maybe 8 years ago (on the
> way home from the airport after playing with the Cub, no less). It can be
> done, so don't try to lie to yourself when the 'experts' tell you how
> strong it is and it can never happen. Nobody is forging factory new
Corvair
> cranks, and you probably don't know the history of the one you have, to
> know if it was abused somehow. You could magnaflux it or do some other
> kinds of tests, but I honestly don't know if they could have predicted
that
> crank failure. Unfortunately, I didn't save the old crank as proof. It
> cracked across one of the crank lobes, the one right next to the #4
> bearing. If you think about it, as you go up the crank from the #1
cylinder
> to the #6, each one adds successively more torque to the crank, so that
> last lobe is getting pushed around by all 6 cylinders, while the first
lobe
> only has to turn the distributor/oil pump and the fuel pump eccentric; big
> whoop.
>
> To its credit, the engine was still running with the broken crank when I
> shut it down. I had a sudden nasty vibration and I knew something was
wrong
> deep inside, but I made it maybe 2-3 miles before I pulled into a gas
> station and called for a tow. The first three mains held the bulk of the
> crank in place and aligned, and #4 held the last chunk and the torque
> converter, which I found more surprising, given there weren't at least two
> bearings to support it, and the #4 isn't flanged. I suspect the drive
shaft
> and gyroscopic effect helped with the alighment. The crack remained
aligned
> well enough to continue to 'push' the output section of crank around. I
was
> amazed when I popped the top cover. The case around the bearings wasn't
> even destroyed, more remarkably. It runs in one of my cars today, although
> I wouldn't have it in an airplane.
>
> I think William experimented with driving a prop from the pulley side of
> the crank instead of the flywheel side, but I don't know the mechanics of
> how he set it up.
>
> Jim Ash
>
>
> At 6/27/2003 10:48 PM -0500, you wrote:
> >--> Pietenpol-List message posted by: "Ken Anderson"
<piet4ken@mindspring.com>
> >
> >Years ago I was looking into using a VW engine in a different
application. I
> >decided to pass.
> >I too had concerns with the thrust going through the crankshaft to the
far
> >end .
> >Not just that but the thrust forces have to make 90 degree turns thtough
> >each rod throw too
> >I talked to the Great Planes folks that sell converted VW engines for
> >aircraft and said that it was not an issue. The crank is forged and can
take
> >the load.
> >Great Planes is now selling a thrust unit / prop extension (1:1 ) that
> >attaches to the flywheel end of a VW engine to take the thrust loads.
> >Limbach engines are loosely based on VW. Where is the thrust bearing?
Subaru
> >direct drive applications where is the thrust bearing? Maybe someone has
an
> >answer.
> >
> >Ken
> ...
>
>
Message 10
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| Subject: | Re: Corvair thoughts |
--> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
I agree with the difference in forces between automotive use and aircraft use.
I've blown a head gasket on a 4-cylinder engine at 2000' ATL (Above Tree
Level), and had to nurse the plane down. This kind of thing is just one of
the risks, but it makes me more sensitive to the possibilites.
I haven't ruled out flying behind a Corvair, but I would only do it behind
a late model 110 (maybe a 95). And it would be derated somehow. I knew a
guy that put a V-8 with a reduction gear in place of an OX-5. The FAA
wouldn't sign off on it unless he severely restricted the V-8, so I've seen
the drill before.
Jim Ash
At 6/28/2003 11:11 AM -0500, you wrote:
>--> Pietenpol-List message posted by: "John Ford" <Jford@indstate.edu>
>
>Jim,
>
>Keep in mind that the crank on an aircraft never has an instantaneous
>torsional load of the magnitude it would get from a popped clutch or even
>mildly aggressive driving (such as pulling out on the highway with
>traffic). The load is relatively constant and smoothly applied, even with
>a decent sized prop. I am of the opinion also that the thrust bearing
>would be much more of an issue in a heavier and higher performance
>aircraft than pulling what isn't much more than a big kite! Of course, I
>may be completely wrong for the first time ever in my life... ;-)
>
>John
>
>John Ford
>jford@indstate.edu
>812-237-8542
>
>
> >>> ashcan@earthlink.net Friday, June 27, 2003 11:45:36 PM >>>
>--> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
>
>Ken -
>
>If the crank were just a chunk of straight steel, I probably wouldn't care
>where the thrust bearing is. Pushing the thrust line through 24(?) 90
>degree bends is specifically the scariest part of the thrust-line thing
>for me.
>
>I broke a Corvair crank in two in one of my cars maybe 8 years ago (on the
>way home from the airport after playing with the Cub, no less). It can be
>done, so don't try to lie to yourself when the 'experts' tell you how
>strong it is and it can never happen. Nobody is forging factory new Corvair
>cranks, and you probably don't know the history of the one you have, to
>know if it was abused somehow. You could magnaflux it or do some other
>kinds of tests, but I honestly don't know if they could have predicted that
>crank failure. Unfortunately, I didn't save the old crank as proof. It
>cracked across one of the crank lobes, the one right next to the #4
>bearing. If you think about it, as you go up the crank from the #1 cylinder
>to the #6, each one adds successively more torque to the crank, so that
>last lobe is getting pushed around by all 6 cylinders, while the first lobe
>only has to turn the distributor/oil pump and the fuel pump eccentric; big
>whoop.
>
>To its credit, the engine was still running with the broken crank when I
>shut it down. I had a sudden nasty vibration and I knew something was wrong
>deep inside, but I made it maybe 2-3 miles before I pulled into a gas
>station and called for a tow. The first three mains held the bulk of the
>crank in place and aligned, and #4 held the last chunk and the torque
>converter, which I found more surprising, given there weren't at least two
>bearings to support it, and the #4 isn't flanged. I suspect the drive shaft
>and gyroscopic effect helped with the alighment. The crack remained aligned
>well enough to continue to 'push' the output section of crank around. I was
>amazed when I popped the top cover. The case around the bearings wasn't
>even destroyed, more remarkably. It runs in one of my cars today, although
>I wouldn't have it in an airplane.
>
>I think William experimented with driving a prop from the pulley side of
>the crank instead of the flywheel side, but I don't know the mechanics of
>how he set it up.
>
>Jim Ash
>
>
>At 6/27/2003 10:48 PM -0500, you wrote:
> >--> Pietenpol-List message posted by: "Ken Anderson"
> <piet4ken@mindspring.com>
> >
> >Years ago I was looking into using a VW engine in a different application. I
> >decided to pass.
> >I too had concerns with the thrust going through the crankshaft to the far
> >end .
> >Not just that but the thrust forces have to make 90 degree turns thtough
> >each rod throw too
> >I talked to the Great Planes folks that sell converted VW engines for
> >aircraft and said that it was not an issue. The crank is forged and can take
> >the load.
> >Great Planes is now selling a thrust unit / prop extension (1:1 ) that
> >attaches to the flywheel end of a VW engine to take the thrust loads.
> >Limbach engines are loosely based on VW. Where is the thrust bearing? Subaru
> >direct drive applications where is the thrust bearing? Maybe someone has an
> >answer.
> >
> >Ken
>...
>
>
Message 11
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| Subject: | Re: Cover for Wood Prop |
--> Pietenpol-List message posted by: Jim Ash <ashcan@earthlink.net>
This guy makes custom covers and shows up at Sun 'n Fun every year:
http://www.aircraftcovers.com/
If I ever put my Cub on floats and have to leave it outside, I'll get a
complete set from him. His stuff is all custom, so if you want to pay the
price, I'm sure he could get you a prop cover. It couldn't hurt to call him
and ask. I had a Vinyl cover with a lining for the wood prop on the Cub,
especially when I lived in Florida. You need something that breaths so the
moisture won't stay. You'll also want to keep your prop in a horizontal
position when the plane isn't in use, with or without a cover, so the water
doesn't run down to the lower blade, soak in, and make that side heavier.
Jim Ash
At 6/28/2003 08:12 AM -0700, you wrote:
>--> Pietenpol-List message posted by: "DJ Vegh" <aircamper@imagedv.com>
>
>My Seadoo cover is made from a very heavy canvas type of material. It
>takes the Arizona sun just fine....... but we hardly get rain here.
>
>Maybe try a neoprene material... like they use for wetsuits. Get white if
>you can to help reflect the sun's heat.... neoprene will keep the moisture
>out... It can be found at marine upholstery stores....
>
>
>DJ Vegh
>N74DV
>Mesa, AZ
>www.imagedv.com/aircamper
>
>
>-
>
>----- Original Message -----
>From: "Dick and Marge Gillespie" <margdick@peganet.com>
>To: <pietenpol-list@matronics.com>
>Subject: Pietenpol-List: Cover for Wood Prop
>
>
> > --> Pietenpol-List message posted by: "Dick and Marge Gillespie"
><margdick@peganet.com>
> >
> > Since my newly completed GN-1 may have to live in the Fla. sun and rain
>for awhile, I would like to protect this nice new wooden prop as best I
>can. What would be the best material to make a cover out of without cooking
>it (the prop)?
> >
> > DickG. in Ft.Myers
> >
> >
>
>
Message 12
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| Subject: | Pedals vs Rudder Bar |
--> Pietenpol-List message posted by: Isablcorky@aol.com
Pieters,
I hope I'm not about to stir up a big pot of Piet soup, BUT, will someone
with much more knowledge and experience than I please try to convince me that the
rudder bar as in the plans, 3 inches high, is as good or better than a rudder
pedal 5 or 6 inches high.
Corky in La wanting to be convinced
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