Author: henry kinney <henrykinney@...> Time: Sun Jan 20, 2002 6:15 pm PST Link
Is it appropriate for this list to be used for
commercial self promotion? I think not. I feel that we
should have the recommendations of users not the
supplier himself. Comments?
--- eaainc@a... wrote:
> In a message dated 1/19/02 7:00:24 PM Pacific
> Standard Time,
> zrxordeath@a... writes:
> > 1) Design. This is simple, if you need an engine
> to produce maximum torque
> > at low RPM (like 2700), You don't engineer a short
> stroke, high revving
> > engine for the job,
> >
> > And why then did ROTAX design the 912 and 914 this
> way? They now sell more
> > aircraft engines than anyone I can think of. The
> engine is smooth and very
> > light. Continentals new series of Tierra engines
> were going this route as
> > well.
>
> You would use a large displacement, relatively long
> > stroke engine,
>
> Very old fashion and outdated way of doing things.
> Short stroked and
> > balanced engines have the same or higher life
> expectancy if water cooled and
> > operate under less internal stress and much
> smoother. I am not taking
> > about 12,000 RPM motorcycles but rather 3-4800 RPM
> opposed 4 cylinder
> > engines with 5 main bearings in 11" of crankshaft
> and a 18 LB flywheel.
>
> and keep the piston speed well below the
> theoretical limit of
> >
> > 4000 feet per minute.(ok, engineer types, check me
> on that, school was 10
> > years ago, might be 3000, LOL)
>
> The piston speed of the Lycoming is close to that of
> the Subaru due to the
> Lycomings long stroke so this is not an issue. The
> internal tolerances of
> the Lycoming are not even close to that of the
> Subaru and the water-cooled
> engine has reasonable cylinder head temperatures and
> don't have to run with
> choked bores and 400 degrees F head temps. as a
> design compromise.
> > 2) Liquid cooling, and belt driven overhead cams
> are great, but they offer
> > 2
> > extra points of failure. Most of the engine
> failures I have seen on modern
> > engines are related to failed cam drive belts.
> >
> > When I see statements like these, just thrown out
> for the aviation world to
> > read, brainwashing builders not to try something
> new, due to these half
> > truths written from a negative viewpoint only and
> don't shine any light on
> > the positives, I feel obligated to respond. If
> the cam belt is the
> > strongest argument against using this type of
> engine, well I have good
> > news. Car manufacturers have learned a lot as
> well on this. Belts are now
> > reinforced with Armid fibers (Kevlar) and
> therefore are strong enough to
> > lift a house. We don't replace the belts every
> year during the annual
> > inspection because it is overkill. People just
> don't fly enough to even
> > wear off the factory lettering on the belts. But
> this could be done,
> > replacing the belt during the annual inspection
> every year would also give
> > you the opportunity to spin the idler pulleys by
> hand to check for proper
> > operation. The belt can be replaced in 15 minutes
> in the airplane. It is
> > very accessible behind the engine and not the kind
> of job it would be if
> > the engine was still in the car.
> >
> > The water cooling is very safe and obviously
> should not be compared with
> > that found in cars, even though modern cars are
> reliable as if maintained.
> > In an aircraft, rubber hoses are replaced with
> silicone and the diameter is
> > less than half for great strength and long life.
> Clamps are expensive band
> > type and not the worm-drive type. The oil cooler
> provide 35% of the total
> > cooling so even if a total liquid cooling system
> failure were to happen,
> > the engine could be operated at reduced power for
> a long time.
>
> You break one of these, its
> >
> > All over, you are landing. Soon. This is usually
> due to a lack of
> > preventive
> > maintainance, but I have seen new ones fail too.
> And, there is no highly
> > inspected aviation grade alternative, its Shucks,
> or the dealer.. I
> > recently
> > looked at a Lycoming in the shop that had eaten
> one of its exhaust valve
> > guides, and probably the valve too. It was still
> running, And we just had a
> > Lacair 4 make an emergency landing yesterday
> outside the door from breaking
> > the crankshaft in flight ???? This engine was
> designed for aircraft use
> > and the crankshaft just breaks? and got the owner
>
> > back to the airport. You won't get that from an
> equivalent failure in a
> > subaru, at 5500 RPM. Here is a great example of
> you throwing out negative
> > information. By saying nothing more than 5500
> RPM, you are conveying to
> > those trying to make an educated decision, that
> the Subaru has to run at
> > this RPM to fly. This is not true, the Subaru
> engine have the capability
> > of operating at this RPM (I have test flown my
> engines and gear drives to
> > 7000 RPM) but a normal flight situation is
> 3000-3900 RPM. Holed pistons,
> > and bent valves, are the order of the day
> > here. I'm not real keen on the idea of electronic
> ignition, every seen a
> > battery break a plate? 10 volts wont do good
> things for your spark, a
> > magneto
> > driven engine dosen't care. An over-volt will fry
> the little black box real
> >
> > quick, too. Wow, and on we go??? Ever heard of
> dual battery systems and
> > over voltage protection? The Subaru ECU would
> operate to 36V and as low as
> > 9V.
> >
> > 3) Another member mentioned something about the
> bearing at the front of a
> > Lycoming. This is a very good point. An automotive
> engine's crank is not
> > subjected to much side load at all. I would think
> the asymetrical thrust
> > produced by a propeller, would put a hell of a
> side load on the crank, that
> >
> > was never anticipated by the designer. A gear
> reduction would dampen this,
> > but I ASSume There you go, yes you are assuming a
> bunch of things while
> > writing this. You first introduce yourself and
> back up your credibility by
> > stating that you have done a lot of work on
> engines, and then you throw out
> > all of this non substantiated and speculative
> negative information that has
> > kept aviation from moving forward for 50 years.
> Oh, yes, about the
> > engines. Did I mention the Lancair 4 that broke
> the crank? Well,
> > "Aircraft" engines have a terrible design in that
> they have to drive a
> > propeller at the front of something that further
> aft has tremendous
> > reciprocating motion introduced to it. I don't
> care how big of a front
> > bearing you put on it, it there are harmonics
> going through the shaft like
> > you would not believe. Why do you think it is so
> critical to only run with
> > an approved propeller? The engine will see all of
> the funny forces the
> > propeller is capable of generating. All of the
> thrust forces and all of
> > the radial / gyroscopic / centrifugal forces. In
> the Subaru installation,
> > all the engine has to do is turn. It was designed
> to turn and that is what
> > it does, it turns. Very few of the forces
> generated by the propeller can
> > reach the engine crankshaft. The only connection
> between the crank and the
> > reduction drive is through a 2" long splined
> shaft. This shaft drives the
> > input gear of the reduction drive. The drive is
> fully
=== message truncated ===
=====
Henry W. Kinney
4395 Menge Ave.
Pass Christian, Mississippi
39571
__________________________________________________
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Author: Miller Robert <rmiller3@...> Time: Sun Jan 20, 2002 6:25 pm PST Link
Having the developer himself freely answer questions on a routine basis
is a real benefit to all of us. I have learned quite a bit from the
ongoing question and answer discussions with Jan. I wish that other
engine developers/manufacturers would do the same...
Lycoming/Wilksch/Thielert, etc.
That someone is not afraid to answer even the most critical comments
actually suggests a certain confidence in his engine. If the other
developers are hesitant to answer questions as freely, I would ask why.
I haven't yet gotten to the point of making an engine choice. But,
these discussions are certainly expanding my perspectives about all of
this.
Robert
henry kinney wrote:
> Is it appropriate for this list to be used for
> commercial self promotion? I think not. I feel that we
> should have the recommendations of users not the
> supplier himself. Comments?
> --- eaainc@a... wrote:
> > In a message dated 1/19/02 7:00:24 PM Pacific
> > Standard Time,
> > zrxordeath@a... writes:
> > > 1) Design. This is simple, if you need an engine
> > to produce maximum torque
> > > at low RPM (like 2700), You don't engineer a short
> > stroke, high revving
> > > engine for the job,
> > >
> > > And why then did ROTAX design the 912 and 914 this
> > way? They now sell more
> > > aircraft engines than anyone I can think of. The
> > engine is smooth and very
> > > light. Continentals new series of Tierra engines
> > were going this route as
> > > well.
> >
> > You would use a large displacement, relatively long
> > > stroke engine,
> >
> > Very old fashion and outdated way of doing things.
> > Short stroked and
> > > balanced engines have the same or higher life
> > expectancy if water cooled and
> > > operate under less internal stress and much
> > smoother. I am not taking
> > > about 12,000 RPM motorcycles but rather 3-4800 RPM
> > opposed 4 cylinder
> > > engines with 5 main bearings in 11" of crankshaft
> > and a 18 LB flywheel.
> >
> > and keep the piston speed well below the
> > theoretical limit of
> > >
> > > 4000 feet per minute.(ok, engineer types, check me
> > on that, school was 10
> > > years ago, might be 3000, LOL)
> >
> > The piston speed of the Lycoming is close to that of
> > the Subaru due to the
> > Lycomings long stroke so this is not an issue. The
> > internal tolerances of
> > the Lycoming are not even close to that of the
> > Subaru and the water-cooled
> > engine has reasonable cylinder head temperatures and
> > don't have to run with
> > choked bores and 400 degrees F head temps. as a
> > design compromise.
> > > 2) Liquid cooling, and belt driven overhead cams
> > are great, but they offer
> > > 2
> > > extra points of failure. Most of the engine
> > failures I have seen on modern
> > > engines are related to failed cam drive belts.
> > >
> > > When I see statements like these, just thrown out
> > for the aviation world to
> > > read, brainwashing builders not to try something
> > new, due to these half
> > > truths written from a negative viewpoint only and
> > don't shine any light on
> > > the positives, I feel obligated to respond. If
> > the cam belt is the
> > > strongest argument against using this type of
> > engine, well I have good
> > > news. Car manufacturers have learned a lot as
> > well on this. Belts are now
> > > reinforced with Armid fibers (Kevlar) and
> > therefore are strong enough to
> > > lift a house. We don't replace the belts every
> > year during the annual
> > > inspection because it is overkill. People just
> > don't fly enough to even
> > > wear off the factory lettering on the belts. But
> > this could be done,
> > > replacing the belt during the annual inspection
> > every year would also give
> > > you the opportunity to spin the idler pulleys by
> > hand to check for proper
> > > operation. The belt can be replaced in 15 minutes
> > in the airplane. It is
> > > very accessible behind the engine and not the kind
> > of job it would be if
> > > the engine was still in the car.
> > >
> > > The water cooling is very safe and obviously
> > should not be compared with
> > > that found in cars, even though modern cars are
> > reliable as if maintained.
> > > In an aircraft, rubber hoses are replaced with
> > silicone and the diameter is
> > > less than half for great strength and long life.
> > Clamps are expensive band
> > > type and not the worm-drive type. The oil cooler
> > provide 35% of the total
> > > cooling so even if a total liquid cooling system
> > failure were to happen,
> > > the engine could be operated at reduced power for
> > a long time.
> >
> > You break one of these, its
> > >
> > > All over, you are landing. Soon. This is usually
> > due to a lack of
> > > preventive
> > > maintainance, but I have seen new ones fail too.
> > And, there is no highly
> > > inspected aviation grade alternative, its Shucks,
> > or the dealer.. I
> > > recently
> > > looked at a Lycoming in the shop that had eaten
> > one of its exhaust valve
> > > guides, and probably the valve too. It was still
> > running, And we just had a
> > > Lacair 4 make an emergency landing yesterday
> > outside the door from breaking
> > > the crankshaft in flight ???? This engine was
> > designed for aircraft use
> > > and the crankshaft just breaks? and got the owner
> >
> > > back to the airport. You won't get that from an
> > equivalent failure in a
> > > subaru, at 5500 RPM. Here is a great example of
> > you throwing out negative
> > > information. By saying nothing more than 5500
> > RPM, you are conveying to
> > > those trying to make an educated decision, that
> > the Subaru has to run at
> > > this RPM to fly. This is not true, the Subaru
> > engine have the capability
> > > of operating at this RPM (I have test flown my
> > engines and gear drives to
> > > 7000 RPM) but a normal flight situation is
> > 3000-3900 RPM. Holed pistons,
> > > and bent valves, are the order of the day
> > > here. I'm not real keen on the idea of electronic
> > ignition, every seen a
> > > battery break a plate? 10 volts wont do good
> > things for your spark, a
> > > magneto
> > > driven engine dosen't care. An over-volt will fry
> > the little black box real
> > >
> > > quick, too. Wow, and on we go??? Ever heard of
> > dual battery systems and
> > > over voltage protection? The Subaru ECU would
> > operate to 36V and as low as
> > > 9V.
> > >
> > > 3) Another member mentioned something about the
> > bearing at the front of a
> > > Lycoming. This is a very good point. An automotive
> > engine's crank is not
> > > subjected to much side load at all. I would think
> > the asymetrical thrust
> > > produced by a propeller, would put a hell of a
> > side load on the crank, that
> > >
> > > was never anticipated by the designer. A gear
> > reduction would dampen this,
> > > but I ASSume There you go, yes you are assuming a
> > bunch of things while
> > > writing this. You first introduce yourself and
> > back up your credibility by
> > > stating that you have done a lot of work on
> > engines, and then you throw out
> > > all of this non substantiated and speculative
> > negative information that has
> > > kept aviation from moving forward for 50 years.
> > Oh, yes, about the
> > > engines. Did I mention the Lancair 4 that broke
> > the crank? Well,
> > > "Aircraft" engines have a terrible design in that
> > they have to drive a
> > > propeller at the front of something that further
> > aft has tremendous
> > > reciprocating motion introduced to it. I don't
> > care how big of a front
> > > bearing you put on it, it there are harmonics
> > going through the shaft like
> > > you would not believe. Why do you think it is so
> > critical to only run with
> > > an approved propeller? The engine will see all of
> > the funny forces the
> > > propeller is capable of generating. All of the
> > thrust forces and all of
> > > the radial / gyroscopic / centrifugal forces. In
> > the Subaru installation,
> > > all the engine has to do is turn. It was designed
> > to turn and that is what
> > > it does, it turns. Very few of the forces
> > generated by the propeller can
> > > reach the engine crankshaft. The only connection
> > between the crank and the
> > > reduction drive is through a 2" long splined
> > shaft. This shaft drives the
> > > input gear of the reduction drive. The drive is
> > fully
> === message truncated ===
> =====
> Henry W. Kinney
> 4395 Menge Ave.
> Pass Christian, Mississippi
> 39571
>
> __________________________________________________
> Do You Yahoo!?
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[Non-text portions of this message have been removed]
Author: Robert McCallum <robert.mccallum2@...> Time: Sun Jan 20, 2002 6:47 pm PST Link
Henry;
When the original statements are supposition, speculation, generalizations, and ASSumption then
scientifically or experimentally backed facts, even if they are from the supplier, are welcome. (
The emphasis above refers to the fact that any time you assume you make an ASS out of "U" and "ME")
I do, however, agree that input from users without a stake in the item are also valuable
testimonials. (pro or con)
respectfully
Bob McC
henry kinney wrote:
> Is it appropriate for this list to be used for
> commercial self promotion? I think not. I feel that we
> should have the recommendations of users not the
> supplier himself. Comments?
> --- eaainc@a... wrote:
[Non-text portions of this message have been removed]
Author: "davidd010" <david010@...> Time: Sun Jan 20, 2002 7:04 pm PST Link
re "Is it appropriate for this list to be used for commercial self
promotion?"
It must be pointed out that Jan was responding to a some thought
provoking observations by an individual who seems to know more about
engines than most of us. I thoroughly enjoyed reading both messages
and hope this type of dialogue continues.
dd
Flying a Cozy
Building an RV7