Eco-Fly Smart deisel

Discussion in 'General Auto Conversion Discussion' started by Riggerrob, Jan 16, 2015.

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  1. Jan 16, 2015 #1

    Riggerrob

    Riggerrob

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    Eco-Fly introduced their Smart Deisel engine at a fly-in in Florida this week. It is converted from the Mercedes Benz diesel installed in Smart Cars. The engine pumps out about 80 horsepower, but weights (89 kilograms installed) considerably more than competitive Rotax engines (e.g. Rotax 912 weights about 64 kg.) How does this installed weight compare with other (80 hp.) gasoline engines? Specifically, VW conversions, Rotax and Continentals likely to be installed in a Thatcher CX-5? Is the Eco-Fly Smart engine too heavy for a CX-5? It is important that we compare "installed weights" with "installed weights" to get an honest comparison. Ideally we would compare "firewall forward" weights that include: spinners, propellers, cowlings complete induction systems, complete exhaust systems, complete ignition systems, starters, and engine mounts. AVWeb published quick video on www.youtube.com.
     
  2. Jan 16, 2015 #2

    Workhorse

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  3. Jan 17, 2015 #3

    dino

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    You also have to compare prop RPM, so the engine it is compared to should be set up with reduction gear. Either that or compare it to the Smart diesel without its reduction gear. About 30lbs is a low estimate of the reduction gear weight. Remember the flywheel weight of a diesel is substantial.

    Dino
     
  4. Jan 17, 2015 #4

    Himat

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    The Eco-Fly Smart diesel is a turbocharged engine too.
    Comparing it to a natural aspired engine and height above sea level will change comparison depending on the turbo set up.
     
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  5. Jan 17, 2015 #5

    autoreply

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    Installed, fwf weight:

    912S=> "big" 80 hp VW => Ecofly Diesel

    Every step is about 15 kg, or about 33 lbs.
     
  6. Jan 17, 2015 #6

    Riggerrob

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    Most automotive diesels are now turbocharged. Let' ignore the turbo-charger ad just count t as "standard"
    Since most of my flying will below 10,000 MS, a turbo-charger will make little difference in performance.

    Let's return to my original question about comparing the "firewall forward" weight of the Eco-Fly Smart diesel with other 80 horsepower engines.
     
  7. Jan 17, 2015 #7

    Himat

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    With only data published on internet as a source, it look like autoreply does a fair guess. (Or he have experience with the alternatives.)The weight difference look like 20 to 30kg in favor of the Rotax.

    My comment about the turbo was mostly aimed at those that operate at higher altitudes. The turbo engine probably suffer less power loss with altitude, and that might be a factor in the power to weight ratio considerations.
     
  8. Jan 17, 2015 #8

    Riggerrob

    Riggerrob

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    Of course we include the weight of PSRU.
    Remember my original question about comparing firewall forward weights of various 80 horsepower engines?
    Eco-Smart Diesel produces 80 horsepower a 3800 rpm, so it needs a PSRU.

    The Eco-Smart 1:1,8 PSRU turns the propeller a 2110, good for a large diameter propeller, so let's compare it with the firewall forward weight of a Great Plains VW conversion with a PSRU.

    When you ital. the 1:115 PSRU on an Eco-Diesel, it turns the prop at 3310 rpm, so let's compare it with an Aero Vee direct drive.

    Remember folks, the original question as about comparing the firewall forward weights for various 80 hp engines.

    Sure we shold include the weight of PRSU.
     
  9. Jan 19, 2015 #9

    Floydr92

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    you should also include the weight of the fuel. diesels are more torquey so will run lower rpm's, and should use less fuel. over a longish journey that extra 15kg might be negated.
     
  10. Jan 19, 2015 #10

    akwrencher

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    HP is what spins the prop.
    Any engine should be run in the proper RPM range for how it is set up to get optimal power and efficiency.
    Diesel engines do tend to burn less gallons per hour than gasoline engines, but not really because of the rpm range or because they are "torquey". It has more to do with higher compression ratio's and more btu's per gallon of fuel, and little things like no throttle plate restriction, etc. In my experience they are about 25-40 % less fuel burn, but that is very general, as there are lot's of different engines to compare, and it depends on if you are using volume of fuel or weight, etc.
    Spark ignition engines can be set up to run high torque at low RPM's just as easily, but low RPM engines tend to be heavier. Higher revving engines can attain more HP per pound of engine weight than low revving ones, gas or diesel.
    One reason we tend to think of diesel engines as "slow turning" is because it is harder to burn all the slower burning fuel in a high rpm engine. That is changing though with electronic injection on modern diesel engines. Multiple injections per power stroke has added allot of flexibility in design, and is a game changer for compression ignition engines.

    Nice looking power plant above. I hope they are successful.
     
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  11. Jan 19, 2015 #11

    autoreply

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    Car diesels burn way less fuel than a gasoline one... VOLUME.

    Diesel contains more energy per unit of volume, but less energy per unit of mass.

    The fuel burn of an aircraft diesel in kg or lbs/hour is only a fraction lower compared to a good, modern fuel-injected gasoline engine like the Rotax 912iS or the ULpower's.
     
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  12. Jan 19, 2015 #12

    Doggzilla

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    Not to be an a-hole, but try running at 6500 feet and youll appreciate the "slight" difference in air pressure. Its actually quite significant. Even at pressure altitude of 6500 feet, you are almost 20% less air, therefore less power... AND less efficiency.

    At 70 degrees outside, air density at 7000 feet is roughly 25% less. Soooo.... basically any meaningful use of an aircraft would be better off with the Diesel. If you are staying below 3 or 4 k feet and sticking to only local sight seeing, then perhaps it makes sense. For any kind of planned long distance trips or any serious usage, turbodiesel is far better.

    The 150hp diesels are kicking the new O-360s pretty well.
     
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  13. Jan 20, 2015 #13

    Floydr92

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    Autoreply, 10 points for observation, but the calorific values of petrol is only about 5% higher than diesel.

    The suitability of an engine depends on the aircraft and it's mission. Until someone gets out a calculator and works out exactly which engine would be best for a given airframe, the argument is pointless.

    As as torque and rpm and components of hp, then it is clearly beneficial to have higher torque and lower RPM for the same power output, leading to a larger prop diameter, lower fatigue wear in components, lower transmission losses (PSRU) etc.

    the turbo also allows it to take advantage of lower drag at higher altitudes for long flights. if we're arguing over 20kg in engine weight, I'd put my money on the diesel.
     
  14. Jan 20, 2015 #14

    Doggzilla

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    Yep, but the diesels were designed to match or exceed the fixed pitch O-360 in every way... but at lower power levels thanks to the variable pitch prop. Of course a variable pitch prop on an O-360 would give it the advantage in climb, there is nothing that can be done to the O-360 to match the fuel consumption of something with such a high compression ratio as a diesel.
     
  15. Jan 20, 2015 #15

    DangerZone

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    It would be wise not to get fooled by advertizement. The Rotax 912 might be dry about 64kg but once the exhaust, spark plugs, oil, liquids, coolers and other 'accessories' are added none of them is ever below 76kg in the most optimistic case. It ends up usually around 80kg if one wants to turn it on and fly with it. The powers of the Rotax are also slightly less than declared but that's an approximation cause noone can really feel their 80HP is only producing 76HP or the 100HP making 98HP. The same goes for the diesel Ecofly, their engine is indeed some 8kg to 12kg heavier when actually weighted, but the diesel has also less power. Hopefully the power thing is resoved by now cause last year their engine was not available to private builders for sales in Europe. It could be a policy thing, it seems they are looking for big producers so they could sell large numbers of it. I was happy to see it in Friedrichshafen but they offered only the gasoline 102HP one. As the prices of Rotax continue to rise, there's more and more new engines competing against it rather than making a completely new engine like the D-Motor team did. The Italians also promised the Morini engine for aircraft use 2 years ago for 11000€ yet there's still no news and it was supposed to be available for sales in late 2013. In the end, there's many announcements about new engines but when you want to buy one for cash then suddenly there no options.

    That's why some people opted for their own diesel conversions, like these guys in Finland:
    [video=youtube;aY6DOG5pjW0]https://www.youtube.com/watch?v=aY6DOG5pjW0[/video]
     
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  16. Jan 21, 2015 #16

    stol

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    Personally, I would NOT trust stated weights by anyone..... Find a flying plane with that motor, remove it with ALL the components needed for it to fly and weigh the COMPLETE package......... You will be shocked with the additional weight they "forgot" to include... IMHO.
     
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  17. Aug 3, 2015 #17

    Workhorse

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  18. Dec 3, 2015 #18

    popobowa

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    HI GUys, as i am just looking into fitting this engine to a DTA trike (used in Africa: bad mogas, Avgas=nogas!) I have the following data:
    ecoFly CDI : 89kg (complete with radiators+fluids, no mount+prop) which makes it app 18kg heavier than the complete 912S kit. As the turbo will give it same perf. as 912s in most of my conditions (apart from MSL) and I can use diesel or A1 , I will see if its a viable option. As there's no type cert. for that combo I have to "get it through" the local CAA procedures. Shld I go for it ,I'll make posts o progress .
     
  19. Dec 3, 2015 #19
    I assume you already have this, but just in case: http://www.tcaa.go.tz/files/Registr...ght and Ultralight Aeroplanes in Tanzania.pdf
     
  20. Dec 3, 2015 #20

    rv6ejguy

    rv6ejguy

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    Unlikely you'll see 100hp out of this engine for very long. That's going to take a ton of boost...
     
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