RV-6 w/auto engine
Keith Mancus 283-4283
with an auto engine? I'm particularly interested in the Javelin Ford 230V6
conversion. Anyone else who has had experience with this engine would
also be welcome. Does anyone know how many RV's, if any, are flying
with non-aircraft engines?
-Keith Mancus
<man...@sweetpea.jsc.nasa.gov>
PS: I read news only semi-regularly; please email to me or it may disappear
before I get to read it.
Paul Stafford
yes- the Blackmores in Concord re-built their RV4 with a Javelin engine,
much to their dismay. Here's the scoop- the gross weight increased by 150#,
the climb rate was a miserable 1200fpm, and they could not cruise anywhere
near their bretheran behind Lycomings. Not only that, but they suffered
either a broken crank or cam ( can't remember which), and several broken
engine mounts, one on the way to Oshkosh. The conclusions they reached were
that the Javelin conversion does not get anywhere NEAR the claimed horsepower
and weighs much more than a Lycoming. There was much debate a few years ago
about Dave Blanton's horsepower figures and measurements, and the upshot was
that EAA does not now sponsor anything for him, and unlike their usually too
bubbly enthusiasm for alternative engines, does not report on his stuff
anymore.
Doug Bloomberg
In response to the inquiry about auto engines in aircraft, particullary
RV's by keith mancus man...@sweetpea.jsc.nasa.gov.
As previously posted there was a RV-4 which had the Javalin Ford V-6 for
about a year. The plane has a Lyc back into it.
Also a new RV-6 is listed in Van's Aircraft news letter. Its empty weight
is about 200lb more than a simular plane with a Lyc.
I also talked to the man who builds the Buick V8 drive for Aircraft Spruce,
he is going to use it in his RV-6 that he is building.
Also, "Hatch Engines" in Oregon is experimenting with rotary engines. They
found the Mazda totally unsuitable for aircraft use, and have developed
their own rotary.
Finally, a good friend, who's uncle was Chief Design Engineer for Ford Engine
Division. Was asked by my friend, "uncle what do you think about using auto
engines for aircraft" (he explained how they were being used to his uncle).
His uncle's reply, " A person would be a fool to use an autoengine for a
light plane, they weren't designed for that, too heavy, and not built for
the high horsepower generated hours on end."
Doug Bloomberg
do...@alliant.com
RV-6 Builder.
Dick Vangruensven (The Van in Van's Aircraft) says the best engine conversion
he knows of for his planes is to convert $5,000 into a good used Lycoming!
Dan Bergmen
attended Arlington "91 and met with Dick VanGruensen. Richard Finch,and
at least 3 other conversion kit sellers at the show. Richard Finch is a
Mechanical Engineer with a background in Aerospace and Detroit. He owns a
Grumman Traveler and sell a book on converting engines, mostly Chevy v-6
and v-8's. My needs were for a 200 horsepower or more engine weighing
400 lbs or less. After a six month search and analysis, I concluded that the
Mazda 13B rotary was the logical candidate, as it is small, light, reliable
and relatively cheap. I found an racing engine builder in So Cal, Jim
Mederer who is a pilot and Glassair owner. He is presently developing an
engine for cirtification to replace the now discontinued Lycomings. He
convinced me that there is not a fully developed powerplant system based
on any auto engine conversion. There was a very talented mechanic in Watsonville
named Geargo Morse, who converted an aluminum v-8 engine in a skybolt, but
never got it out of the pattern. The most successful conversions I found
were done by Ross Aero in Tucson, Az. These were mostly Subaru Legacy 4
holers, and some Mazda Rotaries. There are rumors of some long distance
flights, but a few success don't make me warm and fuzzy at 8,000 agl over
some unsuitable terrain. I have decided to go Lycoming, because I want to fly,
not experiment with engines. If you are interested, here are some phone no's:
Richard Finch (805) 964-9976
po box 1311, Goleta, CA 93116
Ross Aero, 3824 E. 37th St, Tucson, AZ 85713 (602) 747-7877
George Morse, Prowler Aviation, 3707 Meadow View Dr.,Redding, CA 96002
(916) 365-4524
There is also a magazine dedicated to auto conversions:
Contact!, 2900 East Weymouth, Tucson, AZ 85716. It's $18 for six issues,
no ads, back issues available.
Richard Hankey @HP-PTP (408) 746-5193
Ron Wanttaja
> I am building a Steen Skybolt and was considering an auto conversion.
>
> and Glasair owner... He convinced me that there is not a fully developed
Morse must learn from his mistakes... since this is undoubtedly the George
Morse who developed the Prowler, a fair-sized auto-engined homebuilt that
looks like a WWII fighter. It's powered by a 350 HP aluminum V-8 auto
engine conversion. Dunno what happened with his Skybolt, but the Prowler
does well enough to be taken for test flights by nearly every aviation
magazine. Generally *not* what you do if you've got a problem-ridden
engine.
Only one auto-engine conversion has been widely-enough used to get an idea
of its true performance and reliability: the VW. Not quite what a Skybolt
needs.... :-)
Ron Wanttaja
prang@ssc-bee
...rutgers!uw-beaver!ssc-bee!prang
pr...@ssc-bee.boeing.com
Paul Stafford
lets just say it's powered by an aluminum V-8. The performance numbers I've
read don't indicate that the engine is putting out anywhere near 350hp.
Unless, that is, the prop efficiency is somewhere around 45%.
Unfortunately, it's unsubstantiated numbers that get people really excited
before they should be.
Fortunately, the EAA is currently involved in an effort to substantiate
manufacturers' numbers. I am involved in an effort to develop an in-flight
torque meter, which, with RPM, will give an exact HP figure. Combined with
the CAFE instrumented boom, the EAA will be able to test-fly a homebuilt, and
measure exactly all flight parameters. This oughta keep the Blantons and others
honest :)
Paul Stafford RV4 N84PS
Jay Maynard
> Fortunately, the EAA is currently involved in an effort to substantiate
> manufacturers' numbers. I am involved in an effort to develop an in-flight
> torque meter, which, with RPM, will give an exact HP figure.
More, more! How do you measure torque on a running engine? How does that
translate into horsepower? What effects do things like prop pitch and
efficiency have on it, both real and as measured? Time for engine performance
101...
--
Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can
jmay...@oac.hsc.uth.tmc.edu | adequately be explained by a .sig virus.
"Last time I tried to eat a Dodge Omni, it damn near ran me over!" --
Josh Fielek, when told that most people are omnivores
David Papworth
>
> lets just say it's powered by an aluminum V-8. The performance numbers I've
> read don't indicate that the engine is putting out anywhere near 350hp.
> Unless, that is, the prop efficiency is somewhere around 45%.
>
I saw a flyer for this thing on a bulletin board
in the Redding, CA airport, quoting some relatively high speed
cruise figure at a fuel usage of 13 G.P.H. as well as
the 350 HP. I really didn't like the flyer when I saw it
(as it seemed to defy basic physics and engineering).
I almost scribbled the following on the flyer:
Now let's see, cruise at 75 percent power (of 350 HP) gives
262 HP. 13 G.P.H. is 78 pounds per hour. 78/262 gives 0.29
lbs per horsepower hour.
The most efficient aircraft and car engines run .4 to .5 pounds
per horsepower hour. 0.29 is quite unlikely.
I strongly doubt the engine can produce 350 HP at ~2700 RPM anyway.
(and I doubt a practical gear drive could handle the torque involved;
ruling out propeller speed reduction.)
Assuming a (very charitable) specific fuel consumption of
.4 lbs/ horsepower-hour and 75 percent power cruise gives us
253 HP max BASED ON THE MANUFACTURER'S OWN SPECS.
Actually 250 HP is a believable and respectable
number but maybe not big enough to sell kit planes.
350 HP seems quite unlikely.
Dan Bergmen
however, because of insurance limitations. This plane uses a 215 ci Buick
v8. The Prowler uses an aluminum block Chevy small block, stroked to 350
ci. The Prowler kit sells for somewhere around $60,000, with the engine.
Geaorge will sell engine conversions for around $8,000. Thanks for the
response, I'm sticking to Lycoming.
Hal Kempthorne
>
>More, more! How do you measure torque on a running engine?
With a "prony brake" (Apply a brake and measure the force on brake's
anchor or mount point)
>How does that translate into horsepower? 1 HP = 33,000 foot/pounds
per second.
I recall a formula something like PLAN where P is the brake mean effective
pressure in pounds, L is the length of the stroke in feet, A is the area of
the cross section of the cylinder (the square of half the bore times pi) in
feet and N is the number of revolutions per minute. There is a constant
but I am unsure of what it was. The virtue of the formula is that it makes
it clear that these four variables are the things to juggle to increase
horsepower. The horsepower generated has to overcome friction so reducing
it gives more output. Some overhaulers increase the power output of the
engines they overhaul by "souping them up" a bit. All they can do, however,
is change P and reduce friction.
>What effects do things like prop pitch and efficiency have on it..?
None. Depending on what you mean by "efficiency", it may increase P.
Your library probably has a book by Ricardo called "The Internal
Combustion Engine" or something like that.
Hal Kempthorne
Debonair N6134V
Fred Black
>translate into horsepower? What effects do things like prop pitch and
>efficiency have on it, both real and as measured? Time for engine performance
I believe that torque guages are available on a number of turbine engines, although
I am not sure whether they measure the torque directly, or measure something else
(perhaps pressure and temperature up and downstream of the turbine wheel,) and
compute torque from that. One way you might be able to measure torque is to
install a strain guage on the crankshaft somewhere between the engines and the prop.
The amount of 'twist' in the crankshaft is a function of the amount of torque it is
under.
Once you know what torque the engine is developing, you can then determine the
power being developed by the speed of the engine. ie:
power = Constant * Torque * RPM
Propeller efficiency is a function of several things including pitch and RPM and
is always less than 1. The amount of power that is consumed developing useful
thrust is
Thrust HP = Engine HP * Prop Efficiency
Thrust HP is what actually determines the performance of the airplane at the time.
Perhaps someone who is more knowledgable about the details of these areas can
comment further.
--
Fred G. Black E-mail: cr...@bnr.ca Bell-Northern Research
PP-ASEL,G P.O. Box 3511 StationC
My opinions only. Ottawa, Ontario
Canada K1Y 4H7