Metal vs Wood or T2 vs VP (Part II)

I'm still getting LOTS of messages from guys who just Don't Get It.

So let me try it again.

It is NOT a question of an RV vs a Falco. The most basic factor is
COST which means we can rule out such high-priced examples. Right now
I've been making comparisons between the VP-I as the 'all wood'
example and Calvin Parker's 'Teenie Two' as the all-metal example.
That will change in the IMMEDIATE FUTURE as more Thatcher CX4's and
Bruce King's BK-1.3 come flying out the door of garages across the
country.

In virtually all cases the ENGINE is the most expensive component.
(The exception is a few ultra-lights.) But ALL of the examples
presented under this 'Metal vs Wood' comparison use a converted
Volkswagen engine. In this comparison I am advocating the use of a
conversion in which the propeller is mounted on the CLUTCH-end of the
crankshaft AND a dynamo coaxially-mounted on the PULLEY-end of the
crankshaft. The induction system uses an updraft carburetor from a
Model A (Tillotson Model X is one example) or from an industrial
engine (various models of Bendix and Zenith).

The ignition system is either stock Volkswagen but using a distributor
having mechanical advance (ie, centrifugal advance). This system may
be upgraded by replacing various components with their electronic
equivalents, such as using an electronic switch instead of the
mechanical breaker points. The best-case would be the CompuFire DS-IX
or similar, in which the single coil is replaced with a dual-coil,
waste-spark system that is electronically triggered. The lower body
of a distributor having mechanical advance would be retained, allowing
the engine to be hand-propped yet able to run efficiently at speeds
above 3000rpm.

As for the airframe, the selection is based on the availability of the
required TOOLS and before we get into the issue of tools too deeply it
must be understood that regardless of your choice SOME tools will be
required.

All of the METAL airframes mentioned mentioned above can be built
using ONLY hand tools, whereas for the 'wooden' airframes, a table saw
is a virtual necessity. Fortunately a portable electric saw may be
pressed into service as a TABLE SAW at a very small price, allowing
accurate production of the required longerons and, in the case of a
'Chugger' type wing, of the sticks needed for ribs.

Performance on the whole is left for future posts but one aspect of
performance must be addressed at the outset and that is the
relationship between flying and safety. To be a good airman, in my
opinion, DEMANDS a given number of landings per month. Ideally, a
group of airmen would keep one or more airframes available to all.
I'm not strong on clubs, having found most degenerate fairly quickly
by non-flying types who see the club as a SOCIAL activity and who tend
to lean their financial shoulder rather heavily on those who are
primarily interested in FLYING rather then dunking their donuts. Yet
it's difficult to define the needed group without making it sound like
a club.

As for doing all of the flying in just one or two airframes, this
reflects the COST of hangars and tie-downs. All of the airplanes
discussed here can be road-towable but in a growing number of cases
the folks running our airports are AGAINST someone flying out of
'their' field unless they pay certain fees. I've nothing against
that; we've all got to eat. But I AM against being forced to pay
hundreds of dollars a month simply to maintain my proficiency. My
suggested solution is to base one or two airplanes at such airport but
to allow those airplanes to be flown by OTHER-THAN their registered
owner.

A couple of people have said it sounds as if I am AGAINST the social
aspects of grass roots aviation. Actually, I'm just the opposite.
What I'm against is some ground hog trying to run us through the
financial wringer simply because we happen to own an airplane.

But what I'm also against is the pilot whose only flight experience is
gained to and from an airshow. Or having them look like duffers when
they are told to land long, or to put it on the green or whatever.
Toward that end I would like to see them practicing precision landings
at some low-traffic field... or at ANY field, when it comes right down
to it. (It is the organization needed for this type of practice that
leads to the 'club-like' definition.)

While none of the planes mentioned here are especially hot STOL
performers, neither do they need a mile of concrete. Without
exception, all can do a full-stop in less than a thousand feet... and
the touch-and-go needed for a spot landing can be done in much less.

Finally (with regard to commonality) all of the planes mentioned here
use a converted Volkswagen engine and, within that frame, a VW engine
using MY methods of conversion, which means the prop is hung on the
clutch-end of the crankshaft, there is a dynamo installed on the
pulley-end of the crank, and the ignition system is an automotive
unit, meaning the Compu-Fire DS-IX or similar. This method of
conversion is not only the least expensive, it is the lightest in
weight AND the most reliable.

Hopefully, that has brought us back to the main theme which is wood
versus metal. Ever bent a LONG flange in metal? Most who haven't are
convinced they can't, unless they use an equally long metal brake.
Long metal brakes are hellishly expensive and if one is needed it
would pretty well blow my argument out of the water. But the fact is,
one is NOT needed. In a similar vein we run into non-metal users who
are convinced using real rivets is either difficult or expensive when
in fact, it is neither.

Over on the other side of the hangar all of the metal-smiths are
pointing fingers at our TABLE SAW, insisting the fact one is required
is proof that it costs MORE to build from wood than from metal. They
have a pretty good point in that a table saw IS needed to achieve the
accuracy required in long cuts, but they've overlooked the fact that a
portable electric saw can be made to serve as a table saw.

Then comes the 'Yabut' arguments: 'Yeah, but if I gotta make a table
saw...' from the metals group being bounced off the 'Yeah, but if I
need an air compressor...' The truth is, you can do rivets using the
SMALLEST of the available air compressors, which leaves both groups
milling around looking for another argument to throw at the other.

While I'm over here laughing :-)

Because the tools you'll need to convert and MAINTAIN your VW
engine exceed by at least an order of magnitude those needed to build
EITHER type of airframe.

Herez why:
Head-plate. Needed to establish the volumetric balance of the engine.
Exhaust valve tool: Needed to determine valve stem-seat wear.
Adjustable push-rod. Needed when setting valve-train geometry.
Chamber volume tools. Needed to measure the volume of your combustion
chambers.
Timing Wheel: Needed to adjust your valve timing.
Valve Spring Tool: Needed to determine valve spring compression
height.
Connecting-rod Tool: Needed when adjusting rod balance.

Shall I get into the tools specific to making your propeller? I think
not. (In fact, I already have... but they are specific to the prop
and listed in the section on propellers.)

The point here is that your decision to build a 'wooden' or a metal
airplane depends largely on what TOOLS you have. But the wood vs
metal argument has no merit because because when it comes to tools --
and that's what it boils down to -- the ENGINE requires more tools
than either type of airframe.

-R.S.Hoover

On Mar 28, 3:59*pm, " wrote:
I'm still getting LOTS of messages from guys who just Don't Get It.

So let me try it again.

It is NOT a question of an RV vs a Falco. *The most basic factor is
COST which means we can rule out such high-priced examples. *Right now
I've been making comparisons between the VP-I as the 'all wood'
example and Calvin Parker's 'Teenie Two' as the all-metal example.
That will change in the IMMEDIATE FUTURE as *more Thatcher CX4's and
Bruce King's BK-1.3 come flying out the door of garages across the
country.

In virtually all cases the ENGINE is the most expensive component.
(The exception is a few ultra-lights.) *But ALL of the examples
presented under this 'Metal vs Wood' comparison use a converted
Volkswagen engine. *In this comparison I am advocating the use of a
conversion in which the propeller is mounted on the CLUTCH-end of the
crankshaft AND a dynamo coaxially-mounted on the PULLEY-end of the
crankshaft. *The induction system uses an updraft carburetor from a
Model A (Tillotson Model X is one example) or from an industrial
engine (various models of Bendix and Zenith).

The ignition system is either stock Volkswagen but using a distributor
having mechanical advance (ie, centrifugal advance). *This system may
be upgraded by replacing various components with their electronic
equivalents, such as using an electronic switch instead of the
mechanical breaker points. *The best-case would be the CompuFire DS-IX
or similar, in which the single coil is replaced with a dual-coil,
waste-spark system that is electronically triggered. *The lower body
of a distributor having mechanical advance would be retained, allowing
the engine to be hand-propped yet able to run efficiently at speeds
above 3000rpm.

As for the airframe, the selection is based on the availability of the
required TOOLS and before we get into the issue of tools too deeply it
must be understood that regardless of your choice SOME tools will be
required.

All of the METAL airframes mentioned mentioned above can be built
using ONLY hand tools, whereas for the 'wooden' airframes, a table saw
is a virtual necessity. *Fortunately a portable electric saw may be
pressed into service as a TABLE SAW at a very small price, allowing
accurate production of the required longerons and, in the case of a
'Chugger' type wing, of the sticks needed for ribs.

Performance on the whole is left for future posts but one aspect of
performance must be addressed at the outset and that is the
relationship between flying and safety. *To be a good airman, in my
opinion, DEMANDS a given number of landings per month. *Ideally, a
group of airmen would keep one or more airframes available to all.
I'm not strong on clubs, having found most degenerate fairly quickly
by non-flying types who see the club as a SOCIAL activity and who tend
to lean their financial shoulder rather heavily on those who are
primarily interested in FLYING rather then dunking their donuts. *Yet
it's difficult to define the needed group without making it sound like
a club.

As for doing all of the flying in just one or two airframes, this
reflects the COST of hangars and tie-downs. *All of the airplanes
discussed here can be road-towable but in a growing number of cases
the folks running our airports are AGAINST someone flying out of
'their' field unless they pay certain fees. *I've nothing against
that; we've all got to eat. *But I AM against being forced to pay
hundreds of dollars a month simply to maintain my proficiency. *My
suggested solution is to base one or two airplanes at such airport but
to allow those airplanes to be flown by OTHER-THAN their registered
owner.

A couple of people have said it sounds as if I am AGAINST the social
aspects of grass roots aviation. *Actually, I'm just the opposite.
What I'm against is some ground hog trying to run us through the
financial wringer simply because we happen to own an airplane.

But what I'm also against is the pilot whose only flight experience is
gained to and from an airshow. *Or having them look like duffers when
they are told to land long, or to put it on the green or whatever.
Toward that end I would like to see them practicing precision landings
at some low-traffic field... or at ANY field, when it comes right down
to it. (It is the organization needed for this type of practice that
leads to the 'club-like' definition.)

While none of the planes mentioned here are especially hot STOL
performers, neither do they need a mile of concrete. *Without
exception, all can do a full-stop in less than a thousand feet... and
the touch-and-go needed for a spot landing can be done in much less.

Finally (with regard to commonality) all of the planes mentioned here
use a converted Volkswagen engine and, within that frame, a VW engine
using MY methods of conversion, which means the prop is hung on the
clutch-end of the crankshaft, there is a dynamo installed on the
pulley-end of the crank, and the ignition system is an automotive
unit, meaning the Compu-Fire DS-IX or similar. *This method of
conversion is not only the least expensive, it is the lightest in
weight AND the most reliable.

Hopefully, that has brought us back to the main theme which is wood
versus metal. Ever bent a LONG flange in metal? *Most who haven't are
convinced they can't, unless they use an equally long metal brake.
Long metal brakes are hellishly expensive and if one is needed it
would pretty well blow my argument out of the water. *But the fact is,
one is NOT needed. *In a similar vein we run into non-metal users who
are convinced using real rivets is either difficult or expensive when
in fact, it is neither.

Over on the other side of the hangar all of the metal-smiths are
pointing fingers at our TABLE SAW, insisting the fact one is required
is proof that it costs MORE to build from wood than from metal. They
have a pretty good point in that a table saw IS needed to achieve the
accuracy required in long cuts, but they've overlooked the fact that a
portable electric saw can be made to serve as a table saw.

Then comes the 'Yabut' arguments: *'Yeah, but if I gotta make a table
saw...' from the metals group being bounced off the 'Yeah, but if I
need an air compressor...' *The truth is, you can do rivets using the
SMALLEST of the available air compressors, which leaves both groups
milling around looking for another argument to throw at the other.

While I'm over here laughing :-)

Because the *tools *you'll need to convert and MAINTAIN your VW
engine exceed by at least an order of magnitude those needed to build
EITHER type of airframe.

Herez why:
Head-plate. *Needed to establish the volumetric balance of the engine.
Exhaust valve tool: *Needed to determine valve stem-seat wear.
Adjustable push-rod. *Needed when setting valve-train geometry.
Chamber volume tools. Needed to measure the volume of your combustion
chambers.
Timing Wheel: *Needed to adjust your valve timing.
Valve Spring Tool: *Needed to determine valve spring compression
height.
Connecting-rod Tool: *Needed when adjusting rod balance.

Shall I get into the tools specific to making your propeller? *I think
not. *(In fact, I already have... but they are specific to the prop
and listed in the section on propellers.)

The point here is that your decision to build a 'wooden' or a metal
airplane depends largely on what TOOLS you have. *But the wood vs
metal argument has no merit because because when it comes to tools --
and that's what it boils down to -- the ENGINE requires more tools
than either type of airframe.

-R.S.Hoover

Have you ever thought of a Pietenpol?
Corvair engine is good with a very few mods.
I built one and finished it itn 1975, and still have it and it will
perform good.
Flew it to Mr. Pietenpols' strip several times and Oshkosh and
Brodhead WS from
southern Ohio.
JimV.

On Mar 28, 5:28*pm, dpilot wrote:

Have you ever thought of a Pietenpol?
-----------------------------------------------------------------------------------------

Dear Jim,

It's not that it hasn't been thought of but more that a Piet is
addressing an entirely different 'mission.'

The VP1 is a single-place, VW-powered machine that can be built for a
fraction of the price of a Piet. The Pietenpohl is a two-place
battleship (1" sq longerons!) designed to be powered by an engine from
a Model A Ford. Even when powered by something else it is a LONG way
from a minimum-cost machine.

wrote:
I'm still getting LOTS of messages from guys who just Don't Get It.

So let me try it again.

It is NOT a question of an RV vs a Falco. The most basic factor is
COST which means we can rule out such high-priced examples. Right now
I've been making comparisons between the VP-I as the 'all wood'
example and Calvin Parker's 'Teenie Two' as the all-metal example.
That will change in the IMMEDIATE FUTURE as more Thatcher CX4's and
Bruce King's BK-1.3 come flying out the door of garages across the
country.


In the way of "for what it's worth", I'll drop two cents here...

Bruce's airplanes fly well. and they are very straight forward easy to build
machines.

His Hummel was way too heavy with the full VW and the tiny Hummel wing.
He had one wing stall on takeoff one day early in the game- horsing it off.
He said he saw the runway 90 degrees to where is should be - and only 10 feet
away. Scared him pretty good. But he got back on it and rode it again - all
the way to Sun-N-Fun and back, and to Oshkosh and back.
This is, to my mind, one of the most successful VW airplanes ever.
But it turned out it was not for kids (or ham handed low time pilots!)

The BK-1 was a bit weak kneed - gear nearly collapsed on landing one day.
But I'm sure he has addressed that since then. I suspect that's what the
1.3 is all about.

Do *not* use the simple and inexpensive flat wrap canopy!
Too much buffeting around the windshield - could possibly affect the stab.
The bubble was something like $600, but it's money well spent.

I can't evaluate the CX4, as I've never seen one in the flesh.
But they say if it looks good it will fly good.
(not great grammar , but you get the gist of it?)
It's a beauty all right!



The VP-1 does *NOT* fly well at all, being way too heavy and light on power.
Besides that the control harmony sucks. Ailerons are too heavy, pitch too
light. The two I am familiar with have a service ceiling of 600 feet.
This is not something I'd even consider. Nor recommend to anyone else.



The Teeny Too flies some better - at least from the aspect of handling.
But lands at damned near 65 mph(!) - and the nose gear is not really
up to anything but a smooth runway. (and it NEEDS runway for takeoff).
Controls are very light - really easy to over control.
It would cost about the same as a BK, take about as long to build, and
not perform or handle as well.



Of the examples you are discussing, the only one I'd consider is the King.

The CX4 may prove capable. I'd like to fly one and see!






Richard

You are recommending a corvair?
To Veedubber????

On Mar 28, 2:59*pm, " wrote:
I'm still getting LOTS of messages from guys who just Don't Get It.

So let me try it again.

It is NOT a question of an RV vs a Falco. *The most basic factor is
COST which means we can rule out such high-priced examples. *Right now
I've been making comparisons between the VP-I as the 'all wood'
example and Calvin Parker's 'Teenie Two' as the all-metal example.
That will change in the IMMEDIATE FUTURE as *more Thatcher CX4's and
Bruce King's BK-1.3 come flying out the door of garages across the
country.

In virtually all cases the ENGINE is the most expensive component.
(The exception is a few ultra-lights.) *But ALL of the examples
presented under this 'Metal vs Wood' comparison use a converted
Volkswagen engine. *In this comparison I am advocating the use of a
conversion in which the propeller is mounted on the CLUTCH-end of the
crankshaft AND a dynamo coaxially-mounted on the PULLEY-end of the
crankshaft. *The induction system uses an updraft carburetor from a
Model A (Tillotson Model X is one example) or from an industrial
engine (various models of Bendix and Zenith).

The ignition system is either stock Volkswagen but using a distributor
having mechanical advance (ie, centrifugal advance). *This system may
be upgraded by replacing various components with their electronic
equivalents, such as using an electronic switch instead of the
mechanical breaker points. *The best-case would be the CompuFire DS-IX
or similar, in which the single coil is replaced with a dual-coil,
waste-spark system that is electronically triggered. *The lower body
of a distributor having mechanical advance would be retained, allowing
the engine to be hand-propped yet able to run efficiently at speeds
above 3000rpm.

As for the airframe, the selection is based on the availability of the
required TOOLS and before we get into the issue of tools too deeply it
must be understood that regardless of your choice SOME tools will be
required.

All of the METAL airframes mentioned mentioned above can be built
using ONLY hand tools, whereas for the 'wooden' airframes, a table saw
is a virtual necessity. *Fortunately a portable electric saw may be
pressed into service as a TABLE SAW at a very small price, allowing
accurate production of the required longerons and, in the case of a
'Chugger' type wing, of the sticks needed for ribs.

Performance on the whole is left for future posts but one aspect of
performance must be addressed at the outset and that is the
relationship between flying and safety. *To be a good airman, in my
opinion, DEMANDS a given number of landings per month. *Ideally, a
group of airmen would keep one or more airframes available to all.
I'm not strong on clubs, having found most degenerate fairly quickly
by non-flying types who see the club as a SOCIAL activity and who tend
to lean their financial shoulder rather heavily on those who are
primarily interested in FLYING rather then dunking their donuts. *Yet
it's difficult to define the needed group without making it sound like
a club.

As for doing all of the flying in just one or two airframes, this
reflects the COST of hangars and tie-downs. *All of the airplanes
discussed here can be road-towable but in a growing number of cases
the folks running our airports are AGAINST someone flying out of
'their' field unless they pay certain fees. *I've nothing against
that; we've all got to eat. *But I AM against being forced to pay
hundreds of dollars a month simply to maintain my proficiency. *My
suggested solution is to base one or two airplanes at such airport but
to allow those airplanes to be flown by OTHER-THAN their registered
owner.

A couple of people have said it sounds as if I am AGAINST the social
aspects of grass roots aviation. *Actually, I'm just the opposite.
What I'm against is some ground hog trying to run us through the
financial wringer simply because we happen to own an airplane.

But what I'm also against is the pilot whose only flight experience is
gained to and from an airshow. *Or having them look like duffers when
they are told to land long, or to put it on the green or whatever.
Toward that end I would like to see them practicing precision landings
at some low-traffic field... or at ANY field, when it comes right down
to it. (It is the organization needed for this type of practice that
leads to the 'club-like' definition.)

While none of the planes mentioned here are especially hot STOL
performers, neither do they need a mile of concrete. *Without
exception, all can do a full-stop in less than a thousand feet... and
the touch-and-go needed for a spot landing can be done in much less.

Finally (with regard to commonality) all of the planes mentioned here
use a converted Volkswagen engine and, within that frame, a VW engine
using MY methods of conversion, which means the prop is hung on the
clutch-end of the crankshaft, there is a dynamo installed on the
pulley-end of the crank, and the ignition system is an automotive
unit, meaning the Compu-Fire DS-IX or similar. *This method of
conversion is not only the least expensive, it is the lightest in
weight AND the most reliable.

Hopefully, that has brought us back to the main theme which is wood
versus metal. Ever bent a LONG flange in metal? *Most who haven't are
convinced they can't, unless they use an equally long metal brake.
Long metal brakes are hellishly expensive and if one is needed it
would pretty well blow my argument out of the water. *But the fact is,
one is NOT needed. *In a similar vein we run into non-metal users who
are convinced using real rivets is either difficult or expensive when
in fact, it is neither.

Over on the other side of the hangar all of the metal-smiths are
pointing fingers at our TABLE SAW, insisting the fact one is required
is proof that it costs MORE to build from wood than from metal. They
have a pretty good point in that a table saw IS needed to achieve the
accuracy required in long cuts, but they've overlooked the fact that a
portable electric saw can be made to serve as a table saw.

Then comes the 'Yabut' arguments: *'Yeah, but if I gotta make a table
saw...' from the metals group being bounced off the 'Yeah, but if I
need an air compressor...' *The truth is, you can do rivets using the
SMALLEST of the available air compressors, which leaves both groups
milling around looking for another argument to throw at the other.

While I'm over here laughing :-)

Because the *tools *you'll need to convert and MAINTAIN your VW
engine exceed by at least an order of magnitude those needed to build
EITHER type of airframe.

Herez why:
Head-plate. *Needed to establish the volumetric balance of the engine.
Exhaust valve tool: *Needed to determine valve stem-seat wear.
Adjustable push-rod. *Needed when setting valve-train geometry.
Chamber volume tools. Needed to measure the volume of your combustion
chambers.
Timing Wheel: *Needed to adjust your valve timing.
Valve Spring Tool: *Needed to determine valve spring compression
height.
Connecting-rod Tool: *Needed when adjusting rod balance.

Shall I get into the tools specific to making your propeller? *I think
not. *(In fact, I already have... but they are specific to the prop
and listed in the section on propellers.)

The point here is that your decision to build a 'wooden' or a metal
airplane depends largely on what TOOLS you have. *But the wood vs
metal argument has no merit because because when it comes to tools --
and that's what it boils down to -- the ENGINE requires more tools
than either type of airframe.

-R.S.Hoover

Nice read Bob and as always makes alot of sense. I looked at the VP
and used the plans as a means of determining if I could build the ribs
and bulkheads with store front or scrap lumber. I could and did, but
my height and weight pretty much ruled out the VP for me. Other all
wood possibilities exist though, just as the metal planes you've
mentioned.

Your information about the rear shaft VW engine was much appreciated
as I've purchased the Great Planes Type 1 Engine Assy Manual and found
it to be every bit as good as you'd told me it was. W/O a doubt any VW
engine I build will be a rear drive, if for nothing else due to the
weight savings and lesser amount of money involved.

I'd intended to send you an e-mail asking about the "mission"
differences of the front vs rear drive VW engines but was unable to do
so. Regardless the 1835 cc and 1915cc R/D VW engines are remarkably
affordable looking to me, with the difference between them and the
2180cc cost wise being considerable. HP does indeed cost money as
you've written quite often.

Regards

Joe S.

On Mar 28, 9:20*pm, Copperhead wrote:

... I looked at the VP
and used the plans as a means of determining if I could build the ribs
and bulkheads with store front or scrap lumber. I could and did, but
my height and weight pretty much ruled out the VP for me.
---------------------------------------------------------------

Dear Joe,

Agreed, sadly. The design is such a tumbleweed it limits its market.
Unfortunately, in most cases it doesn't do that until time for that
all-important first flight rolls around. Based on the Volksplane
Group, the exact same features that limit the plane's practicality for
one group of pilots turns out to be one of the most critical factors
for another, in that smaller/lighter pilots often acquire their bird
as a bargain, already built. (But I gotta tell you pard, There is some
BIG people flying Volksplanes. [See their Photos archive. They've got
some wizard videos].)

Since the short-coming (ie, excessive drag) is largely a function of
its design I suspect there are a few examples of cleaned-up copies.
On the other hand, I weighed about 190 when I had my first flight in a
VP1 and found it an enjoyable experience. I was especially impressed
by the coordination of the tail. But the take-off was best described
as leisurely. (I was six feet tall back then. Now, I'm exactly one
vertebrae shorter :-)

-------------------------------------------------------------------------

Your information about the rear shaft VW engine was much appreciated
as I've purchased the Great Planes Type 1 Engine Assy Manual and found
it to be every bit as good as you'd told me it was. W/O a doubt any VW
engine I build will be a rear drive, if for nothing else due to the
weight savings and lesser amount of money involved.

I'd intended to send you an e-mail asking about the "mission"
differences of the front vs rear drive VW engines but was unable to do
so.
-----------------------------------------------------------------------------

Yeah, Steve's manual is pretty good. I think he's also got a video
now. As for tracking me down...

Try:

I've a hunch Steve spends a good part of his life on the
telephone :-) (Steve produces a really beautiful flywheel-mount.
There are some pictures of it in my blog.)

As for the 'mission' business it might help if you couch the question
differently. For example, name all the automobile engine conversions
in which the propeller was attached to the pulley-hub of the
crankshaft?

Then ask yourself 'why?' Because the truth is, putting the prop as
close to the thrust-bearing as possible makes the best kind of sense.
In effect, the typical VW with its prop on the pulley-hub is an
EXCEPTION to the standard practice of auto engine conversions.

As for any reference to the clutch-end of the crankshaft as being the
REAR, it is actually located on the FRONT of the VW engine. At least
it is to those with any experience with Volkswagen vehicles. ( ALL
references for Volkswagen are relative to the driver or the front
bumper.)

I've explained how the first flying VW's used the pulley hub and how
those advantages were lost by the time the engine's displacement
surpassed 1200cc. The sad part of the tale is that everyone continued
to try and emulate the success of the 1000cc engine with its 'built-
in' engine mount.

------------------------------------------------------------------------------------

Regardless the 1835 cc and 1915cc R/D VW engines are remarkably
affordable looking to me, with the difference between them and the
2180cc cost wise being considerable. HP does indeed cost money as
you've written quite often.

------------------------------------------------------------------------------------

The reason for the big difference is that you don't need the special
crankshaft nor the 'Force 1' prop-hub. But depending on which
airframe you're interested in, there may be even LESS COSTLY
alternatives.

In the above you've mentioned 'horsepower.' I understand what you
meant but it would be far more accurate to refer to TORQUE and more
specifically to THRUST. In fact, when it comes to homebuilts, we'd
probably all be better off if we referred to our engines in UNITS OF
FLYABILITY or UF's. It certainly wouldn't be any crazier than the
situation we have now, where some fellow tells you his engine produces
80 horsepower then in the next breath sez it burns only three gallons
per hour. The tricky bit here is that both statements may be
correct.. but it would be impossible for them to be correct AT THE
SAME TIME.

Three gallons of fuel is about 18 pounds One of the most critical
specifications for an engine is its Specific Fuel Consumption, which
is how many POUNDS of fuel it burns PER HOUR to produce ONE
horsepower. Normally aspirated air-cooled engines are clustered near
the .500 mark, meaning they burn about half a pound of fuel per hour
for each horsepower. Economy of scale applies so you'll find a big
radial down near the bottom of the curve and your lawn-mower up near
the top, but your flying Volkswagen will be found clustered with the
small (ie less than 500cid) Lycomings and Continentals.

The best SFC EVER for a spark-ignited, gasoline-fueled aircraft engine
was for those humongous turbo-compound radials like the ones used in
the B-36. Their SFC was under four-tenths of a pound of fuel per
hour. (!!)

Then comes this expert with his converted VW that has an SFC of .225!
By every engineering measure in the world the man should be given the
Nobel prize... right after they give him the Harmon Trophy. I mean,
an SFC of .225! The guy has got to be the best engineering GENIUS of
all time!

(What's that? You're saying he FIBBED a little? Well... okay. But
did he cross his fingers at the same time? Because if he DIDN'T it
means we get to call him 'Liar Liar pants on fi..' What? Ah! He DID
cross his fingers. Ah! You're saying he DID cross his fingers. I
see. Thanks for clearing that up for us.)

Well shucks. I was really looking forward to the Awards Ceremony.

So maybe we should lay horsepower aside for the moment and stick with
just the engine and the prop. Including the prop is the honest way to
do it because you need to figure-in your prop's efficiency. If you're
lucky your prop's efficiency will be between 60% and 70%. That's
because we're using a fixed-pitch prop, which has to be a compromise
between take-off and cruise. If you carve your prop for its optimum
climb (or take-off) performance you're going to have to give away a
lot of fuel during cruise. But if you carve a prop for maximum cruise
performance you're liable to need a mile of concrete to get that puppy
into the air.

Of course, what you'll do is try to find a good compromise between the
two.

But having said all that, you're probably still wondering about this
less expensive option I mentioned, which is to leave your heads and
the crankcase alone -- don't machine them for bigger jugs. Then
install a crankshaft having a longer throw... and a set of longer
connecting rods.

Odds are, you'll stick with a stroke of about 78mm the longest set of
rods you can afford. The savings comes in because you don't have to
do any machining on the crankcase or heads; you use the stock items.
You WILL have to clearance the case because the longer throw is now
going to hit the webs inside the crankcase -- exactly as they would if
you opted for a 2180 -- but clearancing is a minor chore and something
you can do for yourself. So you end up buying a new crank, new rods
and a set of SPACERS that allows all this stuff to bolt together.

What you GET is an engine that develops its torque 'way down near the
bottom of the rpm curve. That means you can carve a more efficient
PROP because it will be spinning a lot SLOWER. Slow means low rpm's
and low rpm's means low wear.

Bottom line is that you get an engine that provides all the TORQUE you
can use. How big is it? Umm lesssee... 78mm crank and stock jugs is
1791cc. You can call it 1800 if you wish.

How many 'horsepower?' Well.... spin it up to about 5000 rpm on the
dyno, you'll probably see about 100hp. For mebbe a minute :-)

-Bob

On Sun, 29 Mar 2009 00:44:22 -0700 (PDT), Bob Hoover
wrote:




Three gallons of fuel is about 18 pounds One of the most critical
specifications for an engine is its Specific Fuel Consumption, which
is how many POUNDS of fuel it burns PER HOUR to produce ONE
horsepower. Normally aspirated air-cooled engines are clustered near
the .500 mark, meaning they burn about half a pound of fuel per hour
for each horsepower. Economy of scale applies so you'll find a big
radial down near the bottom of the curve and your lawn-mower up near
the top, but your flying Volkswagen will be found clustered with the
small (ie less than 500cid) Lycomings and Continentals.


just recently I came across the fuel consumption figures for the
English Pobjoy Niagra radial of the mid 1930's.
it was quoted in those wierd english dimensions of lbs/hp/hour.
converting the figures into the litres per hour I use and corrected
for horsepower differences the Pobjoy Niagra radial has exactly the
same fuel burn efficiency as the Continental O-200.

Stealth Pilot

On Mar 29, 2:44*am, Bob Hoover wrote:
On Mar 28, 9:20*pm, Copperhead wrote:

... I looked at the VP
and used the plans as a means of determining if I could build the ribs
and bulkheads with store front or scrap lumber. I could and did, but
my height and weight pretty much ruled out the VP for me.

---------------------------------------------------------------

Dear Joe,

Agreed, sadly. *The design is such a tumbleweed it limits its market.
Unfortunately, in most cases it doesn't do that until time for that
all-important first flight rolls around. *Based on the Volksplane
Group, the exact same features that limit the plane's practicality for
one group of pilots turns out to be one of the most critical factors
for another, in that smaller/lighter pilots often acquire their bird
as a bargain, already built. (But I gotta tell you pard, There is some
BIG people flying Volksplanes. [See their Photos archive. *They've got
some wizard videos].)

Since the short-coming (ie, excessive drag) is largely a function of
its design I suspect there are a few examples of cleaned-up copies.
On the other hand, I weighed about 190 when I had my first flight in a
VP1 and found it an enjoyable experience. *I was especially impressed
by the coordination of the tail. *But the take-off was best described
as leisurely. (I was six feet tall back then. *Now, I'm exactly one
vertebrae shorter :-)

-------------------------------------------------------------------------

Your information about the rear shaft VW engine was much appreciated
as I've purchased the Great Planes Type 1 Engine Assy Manual and found
it to be every bit as good as you'd told me it was. W/O a doubt any VW
engine I build will be a rear drive, if for nothing else due to the
weight savings and lesser amount of money involved.

I'd intended to send you an e-mail asking about the "mission"
differences of the front vs rear drive VW engines but was unable to do
so.

---------------------------------------------------------------------------*--

Yeah, Steve's manual is pretty good. *I think he's also got a video
now. *As for tracking me down...

*Try:

I've a hunch Steve spends a good part of his life on the
telephone :-) *(Steve produces a really beautiful flywheel-mount.
There are some pictures of it in my blog.)

As for the 'mission' business it might help if you couch the question
differently. *For example, name all the automobile engine conversions
in which the propeller was attached to the pulley-hub of the
crankshaft?

Then ask yourself 'why?' *Because the truth is, putting the prop as
close to the thrust-bearing as possible makes the best kind of sense.
In effect, the typical VW with its prop on the pulley-hub is an
EXCEPTION to the standard practice of auto engine conversions.

As for any reference to the clutch-end of the crankshaft as being the
REAR, it is actually located on the FRONT of the VW engine. *At least
it is to those with any experience with Volkswagen vehicles. ( ALL
references for Volkswagen are relative to the driver or the front
bumper.)

I've explained how the first flying VW's used the pulley hub and how
those advantages were lost by the time the engine's displacement
surpassed 1200cc. *The sad part of the tale is that everyone continued
to try and emulate the success of the 1000cc engine with its 'built-
in' engine mount.

---------------------------------------------------------------------------*---------

Regardless the 1835 cc and 1915cc R/D VW engines are remarkably
affordable looking to me, with the difference between them and the
2180cc cost wise being considerable. HP does indeed cost money as
you've written quite often.

---------------------------------------------------------------------------*---------

The reason for the big difference is that you don't need the special
crankshaft nor the 'Force 1' prop-hub. *But depending on which
airframe you're interested in, there may be even LESS COSTLY
alternatives.

In the above you've mentioned 'horsepower.' *I understand what you
meant but it would be far more accurate to refer to TORQUE and more
specifically to THRUST. *In fact, when it comes to homebuilts, we'd
probably all be better off if we referred to our engines in UNITS OF
FLYABILITY or UF's. *It certainly wouldn't be any crazier than the
situation we have now, where some fellow tells you his engine produces
80 horsepower then in the next breath sez it burns only three gallons
per hour. *The tricky bit here is that both statements may be
correct.. but it would be impossible for them to be correct AT THE
SAME TIME.

Three gallons of fuel is about 18 pounds *One of the most critical
specifications for an engine is its Specific Fuel Consumption, which
is how many POUNDS of fuel it burns PER HOUR to produce ONE
horsepower. *Normally aspirated air-cooled engines are clustered near
the .500 mark, meaning they burn about half a pound of fuel per hour
for each horsepower. *Economy of scale applies so you'll find a big
radial down near the bottom of the curve and your lawn-mower up near
the top, but your flying Volkswagen will be found clustered with the
small (ie less than 500cid) Lycomings and Continentals.

The best SFC EVER for a spark-ignited, gasoline-fueled aircraft engine
was for those humongous *turbo-compound radials like the ones used in
the B-36. *Their SFC was under four-tenths of a pound of fuel per
hour. *(!!)

Then comes this expert with his converted VW that has an SFC of .225!
By every engineering measure in the world the man should be given the
Nobel prize... right after they give him the Harmon Trophy. *I mean,
an SFC of .225! *The guy has got to be the best engineering GENIUS of
all time!

(What's that? *You're saying he FIBBED a little? *Well... okay. *But
did he cross his fingers at the same time? Because if he DIDN'T it
means we get to call him 'Liar Liar pants on fi..' What? *Ah! *He DID
cross his fingers. *Ah! *You're saying he DID cross his fingers. *I
see. *Thanks for clearing that up for us.)

Well shucks. *I was really looking forward to the Awards Ceremony.

So maybe we should lay horsepower aside for the moment and stick with
just the engine and the prop. *Including the prop is the honest way to
do it because you need to figure-in your prop's efficiency. *If you're
lucky your prop's efficiency will be between 60% and 70%. *That's
because we're using a fixed-pitch prop, which has to be a compromise
between take-off and cruise. *If you carve your prop for its optimum
climb (or take-off) performance you're going to have to give away a
lot of fuel during cruise. *But if you carve a prop for maximum cruise
performance you're liable to need a mile of concrete to get that puppy
into the air.

Of course, what you'll do is try to find a good compromise between the
two.

But having said all that, you're probably still wondering about this
less expensive option I mentioned, which is to leave your heads and
the crankcase alone -- don't machine them for bigger jugs. *Then
install a crankshaft having a longer throw... and a set of longer
connecting rods.

Odds are, you'll stick with a stroke of about 78mm the longest set of
rods you can afford. *The savings comes in because you don't have to
do any machining on the crankcase or heads; you use the stock items.
You WILL have to clearance the case because the longer throw is now
going to hit the webs inside the crankcase -- exactly as they would if
you opted for a 2180 -- but clearancing is a minor chore and something
you can do for yourself. *So you end up buying a new crank, new rods
and a set of SPACERS that allows all this stuff to bolt together.

What you GET is an engine that develops its torque 'way down near the
bottom of the rpm curve. *That means you can carve a more efficient
PROP because it will be spinning a lot SLOWER. *Slow means low rpm's
and low rpm's means low wear.

Bottom line is that you get an engine that provides all the TORQUE you
can use. *How big is it? Umm lesssee... 78mm crank and stock jugs is
1791cc. You can call it 1800 if you wish.

How many 'horsepower?' *Well.... spin *it up to about 5000 rpm on the
dyno, you'll probably see about 100hp. *For mebbe a minute :-)

-Bob

"Bottom line is that you get an engine that provides all the TORQUE
you
can use. How big is it? Umm lesssee... 78mm crank and stock jugs is
1791cc. You can call it 1800 if you wish." BH

Now that's just the information I was wanting Bob as I'm looking at
the M-19 Flying Squirrel or the Rag a Bond. It would sure be nice if
the BK 1.3 plans were out, but the Beta testing he's having done is a
positive indication of his intent to do right by others.

Oddly enough I've had more fun researching and experimenting with
plans and parts building then I'd ever have thought possible and have
spent very little money so far. Mostly this has been due to the fact I
already have most of my woodworking power tools as well as a lot of
metal cutting and bending tools.

Regards

Joe S.

On Mar 29, 9:17*am, Copperhead wrote:

Oddly enough I've had more fun researching and experimenting with
plans and parts building then I'd ever have thought possible and have
spent very little money so far. Mostly this has been due to the fact I
already have most of my woodworking power tools as well as a lot of
metal cutting and bending tools.
---------------------------------------------------------------------------------------------------------

Dear Joe,

Normally, when you have the option of building from either aluminum or
wood, you would opt for metal but there are a few cases where wood may
prove to be the better choice. In the mid-1930's Virginias Clark, the
fellow who gave us the Clark-Y airfoil, patented a process of making
plywood called 'Duramold' that was superior to aluminum in several
ways, but especially with regard to compound curves. Howard Hughes
acquired the rights to the process (I believe through Fairchild
Camera) and used it to produce the HK-1 'Hercules' -- which we
generally know as 'the Spruce Goose,' even though it is mostly birch.
The 'K' part of 'HK' referred to Henry J. Kaiser, who was supposed to
assemble the giant flying boat, Hughes to fabricate the parts.

One reason we've never heard much about Dura-mold is because of
fiberglas.... and a small Swiss company that came up with epoxy.
Combine the two and even a back-yard craftsman has the ability to
produce complex parts stronger than steel but weighing as much as two-
thirds less.

-Bob

PS -- I've got a hunch that threads such as this often turn into
something useful.