Double Eagle + orphaned engine = a winner?

On Jul 28, 11:05 pm, Anthony W wrote:

After Bob Hoover's recommendation of the double eagle, I fond myself at
the DE website and thinking I've found my first (maybe only) plane.

I already have a stock 1600cc bug engine to use that is ready to put
together other than a few bits but I'd like to try Bob's suggestions and
go with the 78mm crank. Anybody have a good recommendation on a 78mm crank?

All the AFFORDABLE forged cranks come from China these days, and
seemingly from the same supplier. I got my 82mm crank from California
Imports. I also like Aircooled.net for parts. I can't recall if my
engine builder magnafluxed it; I know he balanced it (as an assembly,
with the rods, the prop hub and extension, and the dynamo hub at the
fan end) and he said it took a bit of grinding to get it to come into
balance. All the journals miked out OK.

DeMello will be taking a German forged crank as a core, and welding
and grinding on it to make what you need. His prices are pretty
reasonable, IMHO, but it will be more than a forged ChinCom crank.

You'll have a choice of journal sizes either way. Chevy journals lock
you into new rods (also ChinCom, at pretty attractive prices these
days). But they will mean less clearancing. The smaller journals
also mean a weaker, less stiff crank. A bad thing in a high RPM
engine, where the inertial forces of the rods and pistons try and yank
the pistons out through the top of the heads. A weak crank will, at
high RPM, let the pistons hit the heads...but at our low RPMs, a case
can be made that Chevy Journals are OK. But then we put prop loads on
that crank...you make your choices.

"Clearanced" VW Journal rods are just run through a grinder so they
don't hang up as much. If you're really on the cheap, you can do that
yourself, just make sure you keep them reasonably balanced, both the
whole rod, and the "big end" and "Little end", see later issues of the
Idiot Book, the HiPo pages in the back, for that. Clearancing the
rods in this way weakens them. You may not need to do this for a 78mm
crank, or you may decide to clearance the case a little more, and
leave the rods alone. IF you are clearancing the case yourself,
you'll need a die grinder.

Steve Bennet's book is a really good reference for building any
stroker engine, and I highly recommend it.

Reusing your existing pistons with the longer stroke crank will pop
the pistons right out the top of the jugs at TDC (negative Deck
Clearance), thus the need for the spacers Veeduber alluded to. Or
new pistons; the "B" style for stroker cranks, with the rod pin moved
down. (Although there is not much call for "B" 85.5mm
pistons.....they may be hard to source). My understanding is that
using the "B" pistons, and a 78mm Chevy Journal crank makes a very
nice stroker engine, with little if any clearancing needed, and few if
any spacers, while still keeping the compression low. I've never
built such an engine, and it would require new pistons and cylinders,
a new crank, and new rods. Starting to get Not So Cheap. Maybe better
you should just slap the Flywheel end hub and extension on your 1600
and have done with it...your call.

I will be turning the engine around and mounting the prop on the big
bearing end of the engine but I'm not sure how I'm going to do that
right now. The Great Planes rear drive looks overly complicated but the
only other system I've seen was on a German website a couple years ago
on a type 4.

Use the new-ish Great Plains "Flywheel Drive" bits. Heavily
influenced by Veeduber.

flybynightkarmarepair wrote:
On Jul 28, 11:05 pm, Anthony W wrote:

After Bob Hoover's recommendation of the double eagle, I fond myself at
the DE website and thinking I've found my first (maybe only) plane.

I already have a stock 1600cc bug engine to use that is ready to put
together other than a few bits but I'd like to try Bob's suggestions and
go with the 78mm crank. Anybody have a good recommendation on a 78mm crank?

All the AFFORDABLE forged cranks come from China these days, and
seemingly from the same supplier. I got my 82mm crank from California
Imports. I also like Aircooled.net for parts. I can't recall if my
engine builder magnafluxed it; I know he balanced it (as an assembly,
with the rods, the prop hub and extension, and the dynamo hub at the
fan end) and he said it took a bit of grinding to get it to come into
balance. All the journals miked out OK.

DeMello will be taking a German forged crank as a core, and welding
and grinding on it to make what you need. His prices are pretty
reasonable, IMHO, but it will be more than a forged ChinCom crank.

You'll have a choice of journal sizes either way. Chevy journals lock
you into new rods (also ChinCom, at pretty attractive prices these
days). But they will mean less clearancing. The smaller journals
also mean a weaker, less stiff crank. A bad thing in a high RPM
engine, where the inertial forces of the rods and pistons try and yank
the pistons out through the top of the heads. A weak crank will, at
high RPM, let the pistons hit the heads...but at our low RPMs, a case
can be made that Chevy Journals are OK. But then we put prop loads on
that crank...you make your choices.

"Clearanced" VW Journal rods are just run through a grinder so they
don't hang up as much. If you're really on the cheap, you can do that
yourself, just make sure you keep them reasonably balanced, both the
whole rod, and the "big end" and "Little end", see later issues of the
Idiot Book, the HiPo pages in the back, for that. Clearancing the
rods in this way weakens them. You may not need to do this for a 78mm
crank, or you may decide to clearance the case a little more, and
leave the rods alone. IF you are clearancing the case yourself,
you'll need a die grinder.

Steve Bennet's book is a really good reference for building any
stroker engine, and I highly recommend it.

Reusing your existing pistons with the longer stroke crank will pop
the pistons right out the top of the jugs at TDC (negative Deck
Clearance), thus the need for the spacers Veeduber alluded to. Or
new pistons; the "B" style for stroker cranks, with the rod pin moved
down. (Although there is not much call for "B" 85.5mm
pistons.....they may be hard to source). My understanding is that
using the "B" pistons, and a 78mm Chevy Journal crank makes a very
nice stroker engine, with little if any clearancing needed, and few if
any spacers, while still keeping the compression low. I've never
built such an engine, and it would require new pistons and cylinders,
a new crank, and new rods. Starting to get Not So Cheap. Maybe better
you should just slap the Flywheel end hub and extension on your 1600
and have done with it...your call.

I will be turning the engine around and mounting the prop on the big
bearing end of the engine but I'm not sure how I'm going to do that
right now. The Great Planes rear drive looks overly complicated but the
only other system I've seen was on a German website a couple years ago
on a type 4.

Use the new-ish Great Plains "Flywheel Drive" bits. Heavily
influenced by Veeduber.

All great info and thanks for sharing but while I'm cheap, I'm not
overly so. I have a new set of cylinder and most of what I need to
build a 1600, I think an extra $500 or $600 into this engine is going to
be worth it. I just want to cover all my options before I spend another
dime on the project.

I was a motorcycle mechanic for more years than I like to admit but this
airplane stuff is rather foreign to me and I'm glad there is some one
like Bob that is willing to share his knowledge with thick headed folk
like me... Anyway I'm not afraid to do a little grinding on the case to
make things fit.

Tony

"flybynightkarmarepair" wrote in message
...

Use the new-ish Great Plains "Flywheel Drive" bits. Heavily
influenced by Veeduber.

Let's not completely forget the late, great Steve Wittman and his V-Witt
racer.

Peter

Peter Dohm wrote:
"flybynightkarmarepair" wrote in message
...
Use the new-ish Great Plains "Flywheel Drive" bits. Heavily
influenced by Veeduber.

Let's not completely forget the late, great Steve Wittman and his V-Witt
racer.

Peter

Getting back to the flywheel drive... I looked at the Great Planes site
and the only way I could find to buy one of their flywheel drives is
with an engine kit.

Tony

On Jul 30, 11:34 am, Anthony W wrote:

Getting back to the flywheel drive... I looked at the Great Planes site
and the only way I could find to buy one of their flywheel drives is
with an engine kit.
-------------------------------------------------------------

Steve has sold me to of them. (See the blog.)

-R.S..Hoover

On Jul 30, 12:18*pm, " wrote:
On Jul 30, 11:34 am, Anthony W wrote:

Getting back to the flywheel drive... *I looked at the Great Planes site
and the only way I could find to buy one of their flywheel drives is
with an engine kit.
-------------------------------------------------------------

Steve has sold me two of them. * (See the blog.)

-R.S..Hoover

Sold me one too. His engine mounts (bought one, sent it back) didn't
work for my airframe, but the point is, Steve will sell you lots of
stuff he doesn't list, either seperately or AT ALL in his catalog. I
bought my Flywheel End Piece from him well before he announced that
engine configuration, and mine wasn't the first he'd sold - airboat
people had been using them for some time.

You can see MY blog for how I'm planning on arranging things:

http://users.lmi.net/~ryoung/2007/10...nversions.html
http://users.lmi.net/~ryoung/2007/05...-flywheel.html
http://users.lmi.net/~ryoung/2007/06...prototype.html
http://users.lmi.net/~ryoung/2007/06...rd-mockup.html
http://users.lmi.net/~ryoung/2007/08...st-system.html
http://users.lmi.net/~ryoung/Sonerai/End_Piece.html

Regarding the Wittman rear drive, I have the plans for it. Don't go
there; it's more trouble than it's worth.

On Jul 30, 5:50 am, "Peter Dohm" wrote:

Let's not completely forget the late, great Steve Wittman and his V-Witt
racer.
------------------------------------------------------

You're comparing apples to oranges. The Wittman arrangement uses an
outboard bearing, the 'flywheel-drive' does not. Significant
reduction in cost, weight & complexity.

I think Steve (Bennett) focus was on providing for a sturdy starter-
drive. But if you stick with the Armstrong starter, the flywheel-
drive proves to be the lightest and least expensive method of attach a
propeller to the VW engine.

-R.S.Hoover

wrote in message
...
On Jul 30, 5:50 am, "Peter Dohm" wrote:

Let's not completely forget the late, great Steve Wittman and his V-Witt
racer.
------------------------------------------------------

You're comparing apples to oranges. The Wittman arrangement uses an
outboard bearing, the 'flywheel-drive' does not. Significant
reduction in cost, weight & complexity.

I think Steve (Bennett) focus was on providing for a sturdy starter-
drive. But if you stick with the Armstrong starter, the flywheel-
drive proves to be the lightest and least expensive method of attach a
propeller to the VW engine.

-R.S.Hoover

Taking the second part first, I agree that it is simply the lighter and
probably stronger method. However, knowing now that they are different, I
will stay with Steve Wittman's method.

Peter