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This is umm?? This dead horse has three broken legs.

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indigoonlatigo(at)msn.com
Guest

Posted: Tue Dec 05, 2006 9:00 pm Post subject: This is umm?? This dead horse has three broken legs.

Dj,



For those wanting more information, I feel I should share this with you.



Again, Eric Wolf runs Wolf Aerospace and is supposed to be currently working 

on a water cooled/direct drive Lyco replacement.



I need to touch basis with him and see whats up. I know, we have all heard 

the same story before.



Read below about the problem with reduction drives on internal combustion 

engines.



I imagine some of these gear wear spots could be minimized by using worm 

drive gearing as it spreads the force out over a greater surface area. Below 

explains the problem well.



Even with this said Eggs are still not out of my thought process. Just more 

food for thought.

[quote]From: "Eric Wolf" <Eric(at)wolfaerospace.com>

To: "'John Gonzalez'" <indigoonlatigo(at)msn.com>

Subject: RE: This is umm??

Date: Mon, 27 Mar 2006 11:30:51 -0800



Hi John. The reason gear reductions are a problem in planes is that you fly

full throttle most of the time. Cars have a torque converter or a clutch

which absorbs the oscillations of the power pulses. The gears of a airplane

gear reduction are constantly beating each other up all the time. The

propeller is fighting the air and is wanting to slow down and the engine

produces a power pulse every 90 degrees of revolution(8 cylinder)(180 for a

4 cylinder). At the point of power the gears are smashed together, as soon

as the power pulse is over the gears slam each other the other way because

of the prop trying to stop due to wind resistance. Its quite nasty and can

set up a harmonic at certain rpm's that can destroy the reduction drive. 

You

know when you are drilling teeth and you get that sweet spot rpm and

everything works well. But then you slow down while cutting and it gets

rough. Same thing kind of. Its not optimum at all but Subaru does not make

an engine big enough to fly a plane. They are getting HP by revving up the

engine then reducing rpm with a gear drive.. The old Conti and Lyc engines

are tough but outdated. I am improving what already works the best.

Bombardier aerospace has an engine that revs to 6000 rpm and was available

in turbo and non turbo It had a gear drive and a small displacement. They

said it would be the engine of choice. I Have heard nothing for a while. I

presume it’s a dead issue. There is no place for a wimpy engine in an

airplane. Everybody gets confused with driving cars as much as we do. An

aircraft engine is the only thing keeping you from crashing,,,,,Why skimp 

on

power or strength or design. I am glad everybody is trying to make these

ridicules engines. Every day you hear of some crazy new design that uses

some new method of engine or some other band aid. Airplanes need big beefy

no excuses power. I would gladly drive a prius. But I want power in my 

plane

or on a passenger jet. I do intend to make a version of my engine with

catalytic converters. The amount of oil, raw fuel and lead spewing out of

our planes today is unacceptable. I am very excited about the future of my

engines. They will be so much cleaner than what we have today. As far as 

the

twin turbos on a Subaru. It’s a good engine but do you really want to have

your kids in an airplane with an overstressed engine that is not made for

aircraft?? Or how about being an unpaid test pilot?



In your RV10, how much can the engine weigh and how much power is

recommended? Do they have a maximum power recommended?

Eric.

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dlm46007(at)cox.net
Guest

Posted: Tue Dec 05, 2006 9:44 pm Post subject: This is umm?? This dead horse has three broken legs.

I know nothing about this new engine entry but did notice that it is based 

in Canada. Having lived outside the USA for many years, one learns that 

there are many different laws affecting business transactions.   The 

difficulty and cost of enforcing a business transaction where they have your 

money and your new engine can be daunting. Ask some of the RV builders who 

have dealt with Crossflow or Mistral.

---

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LloydDR(at)wernerco.com
Guest

Posted: Wed Dec 06, 2006 6:40 am Post subject: This is umm?? This dead horse has three broken legs.

This is a well thought out reply, and I have food for thought as I asked

Jan the same thing about the gear loading, and damping the pulses from

the engine. He explained that yes there are pulses, and there are

several ways to deal with them, the approach he takes is three fold.

First there is a custom designed light weight prop, this reduces the

overall inertia associated with a large mass spinning, that causes

loading on the gears. This is not to say there still is not loading,

just not as much because of the light turning mass, this also reduces

the typically gyroscopic effect from a standard prop, less weight less

precision acting on the spline to the gear box. In addition, Jan also

uses a three way spring system in the large torque dampener on the

engine, these springs take the mass of the fly wheel and counteract them

by opposite springs absorbing the pulses. The third approach, is to use

worm gears, further spreading the load across the face of the teeth. The

result is a very smooth running engine, that has the pulses reduced as

much as possible. There have been strain gauge tests done to monitor the

pulses, and the information is readily available from Jan.

In addition, it is not a twin turbo setup, rather a single stage that is

used to hold 32" up to 18K feet. There is some boost added down low, but

not enough to over stress the engine as your friend try's to imply.

Also Fuji industries, maker of the Subaru engines, got its start making

aircraft engines, and after the war had to convert to peace time

activities. What most people do not think about is that the Subaru

Legacy engines are a horizontally opposed 6, just like a Lycoming, so

they do share that design principle. 

One of the big disparities is displacement, Lycoming is 540 cubic inch

engine, while the Subaru is 183 cubic inches. I do agree with your

friend stating that he wants max power available, we all agree on that.

But if we can get the same or slightly less HP in a smaller package, why

not? Less weight equals more useful load for the same HP. I know the

Subaru FWF package weighs 468 LBS total, includes engine mount, cooling,

radiators, sensors, wiring, oil, and Sensi prop etc. I also know the

Lycoming, configured in a like configuration,  with Hartzell,

accessories, oil cooler, plumbing, and baffling etc will come in higher

than that, but no one has weighed a Lycoming FWF package. You can take

the base numbers, add them together and it is higher to start with, let

alone once it is all mounted. 

So, long story short we still have to wait until next summer to get

performance numbers and see what it really is.

Dan   



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indigoonlatigo(at)msn.com
Guest

Posted: Wed Dec 06, 2006 7:15 am Post subject: This is umm?? This dead horse has three broken legs.

This is Ontario just east of Los Angeles.

Not Canada.



JOhn

[quote]From: "David McNeill" <dlm46007(at)cox.net>

Reply-To: rv10-list(at)matronics.com

To: <rv10-list(at)matronics.com>

Subject: Re: FW: RE: This is umm?? This dead horse has three 

broken legs.

Date: Tue, 5 Dec 2006 22:43:36 -0700






I know nothing about this new engine entry but did notice that it is based 

in Canada. Having lived outside the USA for many years, one learns that 

there are many different laws affecting business transactions.   The 

difficulty and cost of enforcing a business transaction where they have 

your money and your new engine can be daunting. Ask some of the RV builders 

who have dealt with Crossflow or Mistral.

---

- The Matronics RV10-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?RV10-List

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