If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
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 |
#32
|
|||
|
|||
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 |
#33
|
|||
|
|||
|
#35
|
|||
|
|||
|
#36
|
|||
|
|||
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 |
#37
|
|||
|
|||
"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 |
#38
|
|||
|
|||
"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 |
#39
|
|||
|
|||
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 |
#40
|
|||
|
|||
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Car engine FAA certified for airplane use | Cy Galley | Home Built | 10 | February 6th 04 03:03 PM |
Objective Engine Discussion | Rick Maddy | Home Built | 26 | October 14th 03 04:46 AM |
Corky's engine choice | Corky Scott | Home Built | 39 | August 8th 03 04:29 AM |
Gasflow of VW engine | Veeduber | Home Built | 4 | July 14th 03 08:06 AM |