Paul,
In case you have not heard, another one of Bud Warren's gear boxes failed
and caused a fatality It was a very nice looking turbo LS1 installation
in
a Glassair 3.

Here is a link to the crash:


http://today.msnbc.msn.com/id/****44733966/ns/us_news-life/<
http://today.msn
bc.msn.com/id/**44733966/ns/us_news-life/


<ht**tp://today.msnbc.msn.com/id/**44733966/ns/us_news-life/<
http://today.ms
nbc.msn.com/id/44733966/ns/us_news-life/

Here is a link to the discussion on the canard forum:
http://forum.canardaviation.****com/showthread.php?t=5706<http**


://forum.canardaviation.com/**showthread.php?t=5706<
http://forum.canardaviat
ion.com/showthread.php?t=5706

and here is a video of the aircraft taken days before the incident
by Mark Steele:


http://www.youtube.com/watch?****v=q4ZV6NPxeq4<
http://www.youtube.com/watch?
**v=q4ZV6NPxeq4


<http://www.**youtube.com/watch?v=**q4ZV6NPxeq4<
http://www.youtube.com/watch
?v=q4ZV6NPxeq4

Very Sad. Not a good record for Bud's gear boxes and a clutch.

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
<http://n4vy.rotaryroster.net/****<http://n4vy.rotaryroster.net/**
http://RotaryRoster.net <http://rotaryroster.net/

Not necessarily the gear box. They both also had Chevy LS1 engines.
That is a very low duty cycle engine with cast iron crank, rods and
cast pistons. Many Chevy V8 powered experimental aircraft have
crashed in the last twenty years with all kinds of gear boxes.

I had gone to OSH just about every year up until this year
and each year yet another new Chevy V8 project was touted. A year or
two later and they were gone. People get seduced by the promise
of 400 HP when in reality the engine is designed for 40 HP.

I am the last person in the world that will admit an automotive
piston engine is up to aircraft duty cycle requirements. As time
goes on the automotive piston engine is better designed to get as
much cost out as possible and still fit the automotive duty cycle.
Automotive piston engine will catastrophically fail without warning
around 300 hours.

The reason the FAA demands an annual inspection on certified aircraft
engines
is to detect incipient exhaust valve failure. The reason a TBO is assigned
by the FAA as experience has shown that particular aircraft engine
will go that long without a major part catastrophically failing
other than an exhaust valve or two.

Here is an article written by Don Sherman a former student of mine.

http://www.rotaryeng.net\DS-****smith-art.pdf

* Smithsonian Air & Space magazine article "Power Struggle" by Don
Sherman, January 1997, page 72. Excellent ten page article (with
many pictures) about auto engines in airplanes. A brief history of
all auto engines in airplanes and a more detailed history of the
twenty year, twenty million dollar development of the Chevy V8
based, all aluminum Orenda liquid cooled aircraft engine. At this
time (Jan 1997) and well after the article was written the engine
failed its FAA 150 hour full power certification test due to a
crankshaft problem after 20 years of very expensive development.
It was finally certified in 1998 by Transport Canada.

Extensive changes have been made to the basic Chevy big block engine
including a parallel cooling system with dual coolant pumps as
opposed to the serial cooling system with single pump as typically
found in automotive engines. Parallel cooling systems were
considered to be essential in the 1920's on liquid cooled aircraft
engines.

Engine length is almost everything to a car designer. Engine cooling
compromises are made by simezing the cylinder walls in automotive
engines. Crankshaft life at high continuous power is compromised by
shortening the length, leaving too little room for adequate size
journal fillet radii. In my opinion this engine will not be
successful until it is re-designed from a clean sheet of paper to be
a real aircraft engine. If that happens they might as well go to a
horizontal opposed configuration for lighter weight.

Orenda was in the process of moving the project to Nova Scotia
and injecting another 32 million dollars of mostly Canadian
government money. They where also attempting to market the engine to
the homebuilt market. I did not expect many takers at over $100K per
engine.

Several years ago Lancair gave up after spending a lot of money installing
the engine in a special airplane called the Lancair Tigress.
The engine and the Tigress were donated to the EAA museum as
a tax write off.

The Orenda company is now bankrupt.

"Those that fail to learn from history are doomed to repeat it."

It is not for nothing that real aircraft piston engines cost $20,000
and up. You are paying for the best materials and manufacturing techniques
available. They are designed to last 1500 to 2000 hours in aircraft
service.

It is just unadulterated luck for us that the Wankel is far more robust
than it needs to be for automotive use and can live in aircraft service.

Paul Lamar

Does a build center exist somewhere in the United States where you
can get hands on help learning to recondition your Wankel Rotary
Engine for installation in an Experimental Aircraft?

Seems like the largest danger with the Wankel Rotary Engine is knowledge.
Once you have a baseline of knowledge, and continue to maintain the engine
as trained at a build center, it will eliminate many of the normal dangers
of a piston engine such as the Chevy LS engine.

GFCurtis Jr.

Not that I know about.
The cheapest way is to buy a junk engine and take it apart yourself.
The best thing about it is there is no machining of any kind required
to rebuild them. Once you take one apart you discover how easy it is.
I think Ed Carver will back me up on that as he has been in it
for less than a year as I recall.

You can download free shop manuals here.


http://foxed.ca/foxed/index.**php?page=rx7manual<
http://foxed.ca/foxed/index
.php?page=rx7manual

Several videos are available. Mazdatrix sells them as I recall.

http://www.mazdatrix.com/

Tracy Crook sells one too. Real World Solutions.

Go to any fair sized city and ask around for who fixes Mazda rotary
engines and go there and hang out.

Put "How to overhaul a Mazda rotary" in the youtube search engine you
will get 264 results.

This one has been watched by 20,000 people.


http://www.youtube.com/watch?**v=ijJeUk_GqiI<
http://www.youtube.com/watch?v=
ijJeUk_GqiI

There is no cheap way to eliminate the dangers of the Chevy LS
short of replacing all the parts with aircraft quality materials
and parts. All the knowledge in the world will not help.
It is not cheap to do that. The endurance racers spend as
much as $100,000 on a Chevy V8 to get it to last one 24 hour
race.

The Orenda Chevy based V8 got up to a 1200 hour TBO when it was
finally certified after 30 years of very expensive R&D
and all parts where changed with aircraft quality parts
including the block. At that point they were charging
$100,000 for them.

When I was involved in road racing we would get two hours
out of them and that was it. Almost every part was cracked
including the block. The competitive NASCAR racers get one
new engine per 500 mile 3 hour race. Many laps are done under
the yellow flag.

The stock Mazda RX8 engine on the other hand is raced 10 races
a year for 3 or 4 years without being touched in the Star Mazda
open wheel series. More Mazda rotaries have won more 24 hour races
than any other brand.

Paul Lamar

I have been working on car and motorcycle engines my whole life.
Most of the past 20 years has been working on porsche engines of all
kinds. I have seen many "windowed" (to use Paul's phrase) porsche
engines. I have a Carrillo rod that is bent from taking out the
cylinder after the cheesey porsche piston failed. The list goes on.
Porsche is the closest piston driven car on the road to being a real
race car. The damn things work, and the engines are by far the most
reliable of all mass production piston engines used in racing in
stock form.

The first time I touched a mazda rotary was when I searched
craigslist locally and found an 87 13b for $50 about a year ago.
Took it home and learned. The hardest part to remove was the
flywheel because the 1 7/16 nut holding it on was rusty stuck. The
rotors were rusted in place so I was lucky in that regard, as they
held the e shaft from turning. I got it apart and only the two end
housings were bad.

7 weeks ago I visited the local self serve bone yard and walked out having
paid only $65 including tax, on an 89 13b bare engine in excellent
condition. If I did'nt want to p port it, I would be done with it.
And yes, there are many youtube vids to watch about rebuilding. And
I have watched several of them. Have fun! Pineapple racing has a
series of vids showing how to do many of the important mods for the
rx engines.

I'm heading back to the bone yard next weekend for 1/2 off day.
I love Pick your Part.

Ed Carver

I agree that the Mazda conversions are the most viable auto engine
conversions. But I think Paul is overly harsh on the V-8s. Race engines
as Colin Chapman said should blow up just after they cross the
finish line. If they don't they are too heavy. Blow ups are not as
frequent as they used to be. Typical problems are usually external
the basic engines. Leaking fuel or oil lines, poor cooling systems,
etc. The ones that are working fine we do not hear about, just the
ones that crash. They do crash more than Lycons. In Australia they
are flying two Pawnees with belt drive reductions on LS1 glider
tugs with excellent results. They are only using about 250 hp max.
Operation within the stock power range is certainly the place to
start. With a Wankel there are just is not that many things that
fail in the engine itself.

Murry I Rozansky

I am talking about production piston engines adapted to aircraft.

I am not talking about engines specifically designed for racing.
One can apply aircraft engine principles as far as bore
spacing and other features are concerned to an engine specifically
designed for racing.

A Formula 1 engine is an amazing device specifically designed
to rev to 18,000 RPM using the finest and lightest materials
available. The stroke is less than 1.5 inches. It is like
8 model airplane engines flying in formation :)

Silicon nitride bearings are widely used in Formula 1
engines. Also the wonder metal alloys like beryllium aluminum
have also been used. If we built our rotors out of beryllium
aluminum the 13B or RX8 engine could in theory run to about
20,000 RPM which would about double the power. Of course
I would have to design a six to one gearbox :)

http://www.formula1.com/inside_f1/understanding_the_sport/5280.html

"Revving to a limited 18,000 RPM, a modern Formula One engine will
consume a phenomenal 450 litres of air every second, with race fuel
consumption typically around the 75 l/100 km (4 mpg) mark. Revving
at such massive speeds equates to an accelerative force on the
pistons of more than 8000 times gravity. Unsurprisingly, engine-
related failures remain one of the most common causes of retirements
in races."

"Mindful of the massive cost of these ultra high-tech powertrains,
the FIA introduced new regulations in 2005 limiting each car to one
engine per two Grand Prix weekends, with 10-place grid penalties for
those breaking the rule."

This is a big improvement over the three engines per race that are
common with production piston engine based blocks.

Paul Lamar

-
Many race engines require freshening after each race. Pretty much all
endurance engines that make it to the finish would not go a lot further.
The F1 rules about engine changes really step up the demands on parts and
limit the RPM somewhat. A recip aircraft engine designed to go 2000hrs
between overhauls and also be as light as possible puts tremendous demands
on parts QC and materials specs. It is not the HP output but the duty
cycle
that stresses parts to the fatigue limit. Regarding the glider tow planes,
what is the TBO of these engines? My money says they are inspected
regularly and the overhauls will be at less than 2000 hours. Also what are
the internals? Stock or all forged? The advantage is that even the forged
may be less expensive than AC parts due to more favorable demand which
lowers cost.


Dale Davies

Hi Dale, the TBO is so far unknown. The engines are stock with an
after market computer. The LS engine saves hundreds of thousands of
dollars
over the 2000 hr TBO of the Lycoming which will seldom get to TBO without
some expensive work. Towing is tough on an aircooled engine unless they
are very carefully flown. High power climbs followed by rapid decent:
shock cooling. The durability test cycle that GM engines must pass before
release for production is so tough, I do not think any aircooled aircraft
engine could survive it. I do not remember the exact times but it consists
of 500 hr of 15 min cycles. a minute or two at idle, max power for 3 min.,
a saw tooth between max torque and max power to the end of the 15 min. The
engine has to be within ware limits to pass. Depending on the application
more than one 500hr test is requiered to pass. You can buy a brand new LS
engine for what one Lyc cylinder costs, 2/3 of the savings are due to
higher productivity, lower fuel burn and the use of auto gas. The Lyc
costs
are based on an overhauled engine not new price.
--


Murry I Rozansky

The GM test is is max torque to max RPM for 300 hours.
In real use it may never in its entire life see full power.
Just because the the throttle is wide open does not mean
it is generating full power. It must be WOT full load
at rated RPM. When is the last time you did that with
your car engine? It is like driving on the autobahn
flat out at top speed well over 100 MPH. That can only be done
for a few minutes due to traffic congestion and speed limits. I know.
I have done it many times in rental cars. I burned a valve in an Opel
one time driving it from Rome to Frankfurt in one day back when there
was way less traffic in the early 1980's :)

The FAA test for AC engines is 150 hours max HP for several five minutes
periods at a time and then 75% max HP for the rest of the time. If there
are any failures they start over. The engine is disassembled and
the wear is measured. The initial TBO is then assigned based
on the wear. Usually a TBO is initially set at 1500 hours if the engine
is more or less like a conventional air cooled aircraft engine.
The certified water cooled Chevy big block based Orenda was
assigned a TBO of 1200 hours.

Murry You are exaggerating the cost of the Lyc relative to a Chevy V8.
A cast iron crank and rods Chevy LS-1 crate engine is about $6000
One with forged steel crank and titanium rods the LS7
now $17,000. Less the ECU and wiring harness.
A real bargain but I don't know how long it would last in aircraft
service. It probably depends on how much of the 500 HP you use. Frequently
the air craft gear ratio is set to less than 2:1 and the engine cannot
reach max power RPM. The gear boxes weigh over 100 pounds while
the engine is 400 pounds. Firewall forward wt. with the cooling sys
and prop is a lot more.

http://www.gmperformanceparts.com/


http://www.gmperformanceparts.com/EngineShowcase/index.jsp?engId=LS7&engine=LS7&sku=17802397&engCat=ls



A new Lyc is $20,000 ready to run. I payed $17,000 for a factory reman 230
HP Cont O-470 2000 hour TBO a few years ago. Ready to run with carb and mags.

Cylinders are about $2000 each depending on what is included.

Paul Lamar


I'm not sure where the $20,000 lyc is "ready to run" but I recently blew 2
cylinders on my Viking Continental IO520D that makes 300 HP at 2950 RPM. A
factory reman starts at $25K with no accessories. The price quote on an
installed IO 550 topped $50K.   That's twice what I paid for the plane.

The quote I have to replace the 2 bad cylinders is approximately $3,000 if
no other issues are found. My engine has around 950 hours on it and a 1700
hour tbo and no it didn't make it. My oil is 8.00 per quart and my spark
plugs are $25 each X 12.

My point is that I don't hear of even certified engines reaching TBO without
expensive repairs before it gets there. At $5,000 for a rebuilt 20B, you
could run it for 1000 hours and throw it away and still be money ahead.


Kevin Alderman