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krahmer
12-16-2011, 08:11 PM
Hey guys. I haven't seen this engine mentioned here yet. Subaru EE20 common rail TDI 2.0 max 148hp. Quite a bit of details over here: http://www.rotaryforum.com/forum/showthread.php?t=29550 My home base is at 8000', I need to clear 10k+ to go anywhere, and would love to just fly right up and over some 14ers. :D I'm thinking this engine in a Kitfox-5+, with a Bosch ECU, rev limited at 3000 with a 3-blade 64" elec-adj prop. She'll put out 130hp on jet fuel, and easily take me to 18k. It's a heavy engine at about 300#, but I figure moving the batter(ies) to a calculated spot in the tail will set the CG perfectly. It's only about 16" front-to-back as well. Will typically fly solo and very light. btw, I would mix the fuel with stanadyne performance additive and more importantly lubricity additive when running kerosene. Injectors and pump wouldn't last long without it. The MGL avionics displays can connect to the ECU over the CAN bus, which is awesome to be able to see sensor values with no add'l hardware. What do you think? It seems perfect to me, but would love to get some other input.

thanks,
brian

Av8r3400
12-17-2011, 10:09 AM
I'd love to see a diesel, too. That's all I drive on the ground.

I think that this one, as you said, is probably too heavy for a Kitfox. Plus, I have yet to see one even in a car so availability and service parts will be a big issue.

krahmer
12-17-2011, 08:40 PM
Thanks for the reply. My VW TDI gets me through the mountains fantastically, but is way bigger & heavier, so that isn't an option. It is true that one would have to get most parts shipped from japan or europe, since that engine isn't available here, but I'm hoping I wouldn't be putting parts into it very regularly.

I would like to explore the weight issue more. I wasn't suggesting that it's TOO heavy, just heavier than ideal. Please let me know if I'm missing anything, but I believe weight basically affects 3 things: carrying weight around reduces climb rate and economy, extra weight reduces my useful payload, CG has to be correct. I don't care about the first or the second, as the plane still fits the mission. I'm fairly certain that due to the 16" dimension of the engine fore-aft and the opportunity to use a very long lever (the tail), that CG can still be established right to ideal specs. Does this engine sound like a BAD idea for any reason? The only other turbo engine that seems reasonable to me is the 914. That has a reasonable amount of power, but certainly much less torque and the disadvantage of having gear reduction. And it costs 3x as much.

Av8r3400
12-17-2011, 10:26 PM
I think you'll find out very quickly, a 914 install will be much more cost effective once you factor in getting a non-north American engine (with no support), all of the R&D you will have to do with ECMs, building and rebuilding (several times) engine mounts, propellers, cooling systems for coolant, oil, after-cooler, etc, etc.

I did see a website once (I can't find it now) on a VW TDi conversion that was flying in (I think) the UK. Again very heavy (300# +) and it did require a re-drive, as, I would think, the Subby would, too.

DesertFox4
12-18-2011, 10:36 AM
Does this engine sound like a BAD idea for any reason?
Way too heavy, unsupported, unproven.
The 914 will get you in the air years earlier and you'll have an aircraft that actually meets or exceeds your mission requirement when done building.
Oh, and after 2000 plus hours behind gear reduction Rotax engines, there is no disadvantage.

DBVZ
12-18-2011, 12:15 PM
Diesel has a lot of advantages. Engine may be cheaper to buy, fuel definitely cheaper, could burn jet (may need additive though), higher torque to turn the prop, turbo for altitude, safer in a crash, fuel fed engine fire less likely and easier to extinguish, pretty high energy content in each gallon, some are tuned for peak power at around 2600-2800 which works for direct drive props, mag issues are not an issue, etc etc. Some day it will be common to see GA aircraft burning diesel or jet. It may just be a little early. But if you want to experiment and help the process along for those that follow, great. Seems like that is one reason they have Experimental aircraft.

Mnflyer
12-18-2011, 03:23 PM
Here's another thing besides no support, no firewall forward, to heavy, around these parts diesel fuel is $.75 to $1.00 more than mo-gas and there is no diesel available at airports and I just checked out of 13 airports within 50 miles of me only 2 have jet fuel and it's only $.50 per gal less than av gas 100LL not a bargain in my book no matter how you slice and dice it.

Dave Holl
12-18-2011, 03:32 PM
Mnflyer
Unless you live in the UK!!!!
Save:)

Mnflyer
12-18-2011, 04:30 PM
Hi Dave your saying??? Diesel is less than mo gas or there is diesel at airports?
The facts are diesel in the US cost more than gasoline and that will never change now that its that way.

Av8r3400
12-18-2011, 06:50 PM
When talking diesel (road vehicles), remember that even though the cost per gallon is 10-15% more than the "gasoline" that you have to buy now, you will get 30-40% better fuel economy numbers making the cost per mile much less.

There was an article in Kitplanes a while back comparing the WAM diesel (http://wilksch.net/) versus a typical 320 Lycoming install on an RV9. The WAM motor was at a disadvantage in HP (125 versus the 150 Lycoming?), yet performance was very comparable and fuel consumption (jet a) was much less in the diesel.

Compression ignition engines will eventually see wider use in light planes. They are far superior in efficiency, torque, maintenance and life span to mention only a few. It's only a matter of when the market will bear the development costs.

Mnflyer
12-18-2011, 08:29 PM
When talking diesel (road vehicles), remember that even though the cost per gallon is 10-15% more than the "gasoline" that you have to buy now, you will get 30-40% better fuel economy numbers making the cost per mile much less.

I don't don't think that is true here the cost of diesel is 28% more per gal and while diesels get better mileage input costs of a diesel are more ie filters, oil initial cost that when its all said and done the cost per mile is virtually the same and small diesels don't last any longer then modern gas engines.

DBVZ
12-19-2011, 07:27 AM
Cost relative to MOGAS, diesel is more. Cost relative to AVGAS, diesel is less. And ethanol free MOGAS is not any more available at airports than diesel. At least you can find it locally anywhere off airport, unlike ethanol free. And if it can burn jet, or is on floats so it can fuel at a boat dock with diesel, it would work ok.

krahmer
12-19-2011, 09:41 AM
Hey, we've got a good discussion going here now, I like it! Just a few counterpoints to some points that I didn't agree with: ECU mapping: the seller of these engines has a map for the mentioned ECU. However, diesel ECU maps are going to be an order of magnitude simpler than a gas engine. Think of how forgiving the air/fuel ratios are in a diesel... There is no fine line to walk between fouled plugs and knock, as with gas. My dad is a mechanic (and pretty good fabricator) of over 40 years experience. I expect no significant challenges with motor mount, radiator and intercooler mount & plumbing. The diesel will already get the best fuel economy out there, but if I wanted to be a real cheap *******, I could haul off-road diesel onto the field at my home airport, and pay about $3/gallon. I'm also pretty certain this thing would not need a re-drive. It has max torque at 1800rpm, flat to about 3600rpm. The reason I was thinking of rev limiting it is because I think the 137 theoretical hp at 3000 rpm will be plenty, and going over that increases my chances of overspeeding the plane, and designing to that rpm would keep my prop more efficient at cruise speeds.
I've been watching the Wilksch and Deltahawks for years now, and I think the DH has a very promising future. The $60k FWF kits are scary though. :) To me, this engine is nearly ideal, with the only compromise being weight, which isn't so bad that it rules it out. Like a couple guys said, I think I should experiment!

thanks,
brian

Mnflyer
12-19-2011, 12:06 PM
"Cost relative to MOGAS, diesel is more. Cost relative to AVGAS, diesel is less. And ethanol free MOGAS is not any more available at airports than diesel. At least you can find it locally anywhere off airport, unlike ethanol free. And if it can burn jet, or is on floats so it can fuel at a boat dock with diesel, it would work ok. "
Ok as I understand your post you are saying that its worth it to you to have a diesel in your Kitfox because diesel or jet fuel is less money than Avgas and if on a cross country flight you you need fuel and landing at the nearest airport it has no jet fuel it is all worth it to have to get a ride into town buy a fuel can purchase diesel fuel go back to the airport and try refueling the plane with very stinky diesel balancing on the tire with this can over your shoulder then leave the fuel can behind because I don't know where in a Kitfox you'd carry it (OH I guess you could duck tape it to the wing strut) and you takeoff to do it all over again at the next refuel point. Ahh the joys of having a diesel engine in ones plane.
I know that in some parts of the country finding non alcohol mo gas isn't easy but here in MN its ready available and many more airport have mo gas then jet fuel.
Its all what turns your crank as the saying goes.

Woodennickle
12-19-2011, 01:11 PM
Orville, Wilbur, how many times do I have to tell you that if man were meant to fly, he would have been born with wings!



Remember, somewhere in Kenya, a village is missing it's idiot.:cool:

DBVZ
12-19-2011, 04:20 PM
Its all what turns your crank as the saying goes.
Exactly. So if the OP wants to try to make a diesel engine work, good for him. 100LL has an uncertain future. When diesel aircraft engines become more common, so will diesel fuel at airports. A turbo diesel seems like it ought to be a good fit for aircraft for the reasons already discussed.

krahmer
12-20-2011, 10:34 AM
out of 13 airports within 50 miles of me only 2 have jet fuel and it's only $.50 per gal less than av gas 100LL not a bargain in my book no matter how you slice and dice it.

Again, here is where different people have different operational concerns, and that geography can factor into it as well. I just looked at all of the CO mountain airports, and I couldn't find one that didn't have jet fuel. And jet was cheaper than 100LL at every place except one. I'm not afraid to pop into a class D airport on an XC to pick up fuel if I had to, either, so fuel is the least of my concerns.

thanks,
brian