Diesel engine

On Mon, 26 Apr 2004 20:06:46 -0400, "George A. Graham"
wrote:

On Mon, 26 Apr 2004 wrote:

Hi Corky. You don't really believe that now, do you?

Those motors burn 8 to 10 gph near the ground - that ain't .38.

Hey George, what's your firewall forward ... err, aft weight with the
mazda transmission? Any adea how it compares to, say an o-320 all up?

--
David Munday -
Webpage: http://www.ase.uc.edu/~munday
"Adopt, Adapt, and Improve" -- Motto of the Round Table

On Tue, 27 Apr 2004, it was written:

Hey George, what's your firewall forward ... err, aft weight with the
mazda transmission? Any adea how it compares to, say an o-320 all up?

Hi Dave, It must be very close to the Lycoming, as my airplane weighs
940 lbs empty, same as most O-320 powered canards. But no, I have not
yet weighed the motor separately. I might do so in the future, as I'd
like to repaint my motor mount with epoxy paint.

George Graham
RX-7 Powered Graham-EZ, N4449E
Homepage http://bfn.org/~ca266

On Tue, 27 Apr 2004 wrote:

I mean the engine's going to have this 74" diameter prop on it and
it's bound to vibrate some. How do you tell what's normal and what
isn't?


Burt Rutan says that the prop should turn about 2600 rpm static, and that
also makes a very good cruise rpm. My setup would turn my first prop
over 3000 static, but my good prop only 2400. I use that same number
for my cruise rpm which is 5200 rpm engine speed. I know that it will
run for hours at that speed. No doubt, others will be more sophisticated.

If you do find a resonant rpm, you'll know it right away.

George Graham
RX-7 Powered Graham-EZ, N4449E
Homepage http://bfn.org/~ca266

wrote:
On Tue, 27 Apr 2004 14:15:28 GMT, wrote:


In article , Ernest Christley wrote:
Another strobe that many people have in their shop is an automotive timing
light. You can wind a simple coil of a few dozen turns and put it in the
trigger clip. Then, any convenient signal source such as an audio signal
generator can be used to produce the timing signals.

good luck,
tom pettit


But what's a fella to do with the flashing light? What are you
checking and what's it all mean?

I mean the engine's going to have this 74" diameter prop on it and
it's bound to vibrate some. How do you tell what's normal and what
isn't?

Corky Scott

I like that timing light idea. With my laptop and a simple program I
can have a lot more range than is possible with the RatShack thing I have.

Corky, the strobe will slow down any flexing due to vibrations to the
point where you can clearly see it. Sorta makes it slow motion. I
would say that if you can clearly distinquish the flexing in a motor
mount or other supporting part, then it is way too much, and you should
consider a redesign. It may not tell you anything interesting at all,
it's just an easy way to see what and where the vibration are and how
much they are shaking what. But you are right, just because it's moving
doesn't mean it's coming apart. I'll counter that you can decide what
is normal for yourself once you see it moving, and I'll bet dollars to
donuts that if you do see a lot of movement you'll be an expert on what
is normal before the engine leaves the ground 8*) (Yes, that was a long
winded way of saying, "I don't rightly know.")

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

wrote:

snip

So while the typical auto engine may not be designed to produce
maximum continuous power, they sure can do it.


Even the highest power ratings (for offroad machinery) is for not much over
50%, with car racing next. Just compare the mpg with specific fuel
consumption eg 20 mpg(imp) @ 60 mph = 3gph = 21 lb hr ~ 40 hp @ 0.5
lb/hp/hr for a 150hp motor.


regards

jc

Ernest Christley wrote:

But what's a fella to do with the flashing light? What are you
checking and what's it all mean?

I mean the engine's going to have this 74" diameter prop on it and
it's bound to vibrate some. How do you tell what's normal and what
isn't?

Corky Scott

I like that timing light idea. With my laptop and a simple program I
can have a lot more range than is possible with the RatShack thing I have.

Corky, the strobe will slow down any flexing due to vibrations to the
point where you can clearly see it. Sorta makes it slow motion. I
would say that if you can clearly distinquish the flexing in a motor
mount or other supporting part, then it is way too much, and you should
consider a redesign. It may not tell you anything interesting at all,
it's just an easy way to see what and where the vibration are and how
much they are shaking what. But you are right, just because it's moving
doesn't mean it's coming apart. I'll counter that you can decide what
is normal for yourself once you see it moving, and I'll bet dollars to
donuts that if you do see a lot of movement you'll be an expert on what
is normal before the engine leaves the ground 8*) (Yes, that was a long
winded way of saying, "I don't rightly know.")

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

"I don't rightly know", either, Earnest, but it's fun to play with.

Right on about the motion, and with the vibration of the engine
running there is visible motion.

A guitar string on a guitar that is waving back and forth will move -
back and forth. But the string is still straight. It is just waving
back and forth with the guitar - way below it's resonant frequency.

When plucked, it "bows". Flexes into a new shape. The string is
resonating at some frequency based on the length, tension, and
the string's physical properties (cross section, material, windings?)

When the moment is frozen with the strobe, you can see the curvature.


So the apparent motion of the engine mount tubes is just normal
vibration.

But if there is detectible curvature or flexing, there is a resonant
response.

The thing about the variable frequency strobe is that it makes it
easy to look at different response frequencies on the test article.

Like the choke cable where it looped around the front of the engine -
unsupported.

Dumb.


Richard

"George A. Graham" wrote:

On Tue, 27 Apr 2004, it was written:

Hey George, what's your firewall forward ... err, aft weight with the
mazda transmission? Any adea how it compares to, say an o-320 all up?

Hi Dave, It must be very close to the Lycoming, as my airplane weighs
940 lbs empty, same as most O-320 powered canards. But no, I have not
yet weighed the motor separately. I might do so in the future, as I'd
like to repaint my motor mount with epoxy paint.

George Graham
RX-7 Powered Graham-EZ, N4449E
Homepage http://bfn.org/~ca266

George, reliable information like that is exceptionally hard to come by.

If you go the trouble to weigh everything, please share it with us?


Richard

"Dave Driscoll" wrote in message ...
(snipped) Corky,

I'm pretty sure I've read the article that you are describing in the past and absolutely agree that testing in the automotive world is quite severe.

(snipped)

Given that the original poster in this thread was asking about the converting an automotive diesel its perhaps appropriate to examine the modifications that were made to the Thielert Centurion.

(snipped)

Personally, potential commercial competition aside, I'd love to see the original poster successfully convert a 10 cylinder VW diesel for aviation. I think it would be a really cool project. I'd also do my best as a citizen of the homebuilding community to help him do it safely and successfully. That said, I've been down the path you're on regarding your static test installation. If you're interested, shoot me your e-mail with your number, I think I can save you some grief on that project.

Dave Driscoll
DeltaHawk Engines LLC

------------------------------------------------------------------------------


Truer words were never spoken. This is an admirable attitude that all manufacturers should adopt. Thank you Mr. Driscoll.
If it were not for the cost, the DeltaHawk engine would be my first choice too. With its increased ground clearance, inverted in a Cozy MK-IV, it would be the ideal engine. Its price, however, even though justified, compared to Lycoming and Continetal offerings, would represent half a year's income for me, making it esentially unreachable. As potential alternatives I regard the new common-rail, double or variable geometry turbo-diesels that have recently appeared on the world market. The Isuzu 3.0 liter V6 176 HP, the Ford-Jaguar-Peugeot 2.7 liter V6 207 HP and weighing 202 kg, the VW 2.5 or 3.0 liters V6 TDI 180 - 225 HP 220 kg diesels would all be viable options with their HP to weight ratio of 1/1. Just a quick search on mobile.de for low-mileage, intact motor, accident total write-offs yields several potential donor vehicles for under EUR 5.000. You buy the donor vehicle, remove engine and electronics and sell off the rest to recover some of the initial cost. The cost of the engine alone would be one to two thousand EUR. Then of course, as others in this thread have mentioned, comes the hard part. The Isuzu 3.0 liters V6 with its 177 HP would definitely require a redrive, the Jaguar with its 207 HP and the VW 3.0 liters V6 with its 225 HP and massive torque maybe not. "Die Qual der Wahl". The good thing is that since the airframe won't be ready for another 2-3 years, by that time there will be a reliable track record for these engines. After configuring the engine package there comes the testing. I would never fly behind (er... I mean in front) of an untested junker engine. My test-bed for the next one hundred or more hours, with diligent collection of all pertinent data on my laptop, would be a bayou style air-boat, built on the basis of my little catamaran. If the engine plus redrive plus propeller package survives this ordeal, then it's time for taxiing, eventually flying.
Useful links:
1) Isuzu 3.0 liters V6: http://www.isuzu.co.jp/world/corpora...ne/lineup.html
2) Ford-Jaguar-Peugeot 2.7 liters V6: http://www.histomobile.com/histomob/tech/2/112.htm
3) VW Audi 2.5 - 3.0 liters V6 TDI:
english: http://www.auto123.com/en/info/news/...tid=22231&pg=5
german: http://www.auto-motor-und-sport.de/d/48696
4) And because these are really "schöne Motoren": http://homepage.ruhr-uni-bochum.de/r...r/motoren.shtm
Thank you for reading my ramblings.
Kumaros
It's all Greek to me

Del Rawlins wrote in message ...
In charles.k.scott@
dartmouth.edu wrote:

I think it actually will fit in the back of my pickup (haven't taken
the time to measure yet), and as you know, we live right next to some
pretty dense woods. I could trundle it up to the logging landing
above us and run it all day without bothering anyone.

If it were me, I would try to pick up a used trailer and turn that into
my test stand.

Uh, what about putting a muffler on it? Won't it be flying with
some kind of muffler or tuned exhaust system or something that
cuts the noise?

Hey, I'm just asking.

--

FF

On 28 Apr 2004 15:23:49 -0700, (Fred the Red
Shirt) wrote:

Uh, what about putting a muffler on it? Won't it be flying with
some kind of muffler or tuned exhaust system or something that
cuts the noise?

Hey, I'm just asking.

A muffler was definately part of my original plans, but I just don't
have room to install a muffler and route the exhaust in behind the
radiator to augment the exit airflow. I could test the engine with
several mufflers clamped on though.

It may not make an enormous amount of noise because the exhaust
headers will only be 1 3/8" in diameter and each runner will be 40
inches long. Then they collect into two 2" tubes that themselves will
be about three feet long.

The noise will definately be directional so I might be able to turn
the engine away from the houses and run it without disturbing anyone.

We live next to the woods so if I aim it at the trees... I'll just
have to see how things go.

First I have to fabricate the headers, then set the engine in the test
stand and get serious about running it.

Corky Scott