Return of the D-Motor to the US market

Flynic3

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Good Evening,

Fisher Flying Products will now be the Distributor for the D-motor in North America and will start taking orders for the LF26 4 cylinder engine at OshKosh this year. Dave with Fisher has been working for over three years to make this a reality. Fisher has assembled the team and resources needed to make this engine successful. They will be taking this engine through the ASTM Standards as well. I feel these engines will provide an excellent alternative to the Rotax 912ul engine. With less weight, water-cooled security, modern FADEC control low fuel burn, and a price of $15,699 including everything but a radiator and hoses. This engine had the potential to provide Rotax with a proper market competitor. There are over 40 aircraft flying with the D-motor in Europe and some have reported over 500 hours of trouble free service since 2013! The parent company D-motor Belgium is currently completing a 50 engine contract for the EDM Aerotec Co-axial helicopter project. After this project is complete they will be concentrating on production of engines for the US market. I think the LF26 engine will provide an excellent engine choice for the single place Gyros and the LF39 six cylinder would work outstanding for the 2 place Gyros on the market with 120hp on tap. These motors provide a more simplistic engine design compared to the Rotax with the LF26 only having only 35 moving parts! Having 2.6 liters of displacement the LF26 provides enormous amounts of torque as well with 163ft-lbs! These engines should provide equivalent power to the 912ul and maybe closer to the 912uls. The LF26 has a lot of potential and I feel this engine deserves another look for use in a Gyro application! If you have any further questions about this engine option, I will gladly answer any questions that you may have to the best of my ability. I am looking forward to seeing these engines at OshKosh this year and can’t wait to start seeing them flying on Aircraft within North America!

http://www.d-motor.eu/nl/home-1.htm

Best Regards,

Nicholas Dawson
 

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Since no one will turn a prop at 3000 RPM LF39 is really a 112 HP engine at 2800 RPM at 172 pounds empty dry.
No reduction also means lower torque and somewhat longer to takeoff generally. A realistic installed weight wet would likely be 195 pounds at 112 HP. Rotax 914 is about 178 pounds installed at 115 HP but it has the advantage of a gear reduction allowing the prop to turn at 2400 RPM where it can be much more efficient and quiet while having a good diameter. Would be interesting to see how it fairs. They would have to find propellers that suit this engine power and torque curves properly for both tractors and pushers.
Fuel burn is listed at 5 GPH at 93.5 HP which is pretty much similar to Rotax engines so injection did not seem to get them fuel efficiency which it should have by 6 - 8%.
They do not include weight of engine mount and cooling system (radiator and hoses) in their empty weight. Rotax 914 comes with the ring mount installed but no radiator.

Overall given higher installed weight and direct drive, I expect performance to be a bit higher than 912ULS but not as good as 914.
 
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Also the D-motor is a really old technology engine,its a flat head engine like the old Ford V-8's were.

Due to the valve arrangement there probably isnt much that can be done to improve HP.

But for its application, as a low RPM engine it should be fine as is.
 
I like the D motor design a lot, sure it is old tech, but it works, plus being a side valve engine it is much smaller since the valve train is not in the cyl heads. Also en engine turning @3000 rpm really does not benefit from the extra efficiency of overhead valves at that speed, plus direct drive, no gearbox, simple simple, I really hope that they do well, plus it sounds great!
 
Its designed like an aircraft engine should be,large bore long stroke, low RPM and max torque @2,500 RPM and its fuel injected,

plus its direct drive and being liquid cooled,running in a pusher configuration wont be a problem either. Should be a great engine.
 
How much do they cost?
 
It will certainly become more interesting as much more of the metalurgical details are presented. Sounds like the cylinders are aluminum, without steel liners. At $16 to $17 k-dollars, it would seem much more advantageous to have steel wet sleeves for cylinders. Renault did that with the 900cc Dauphine engine in the early 1960's. And it had overhead valves, making for more flexibility in enhancing the breathing. Mixture flow in side valve engines has to make a u-turn, coming into the combustion chamber, making it very inefficient. What is the valve overlap of these engines?
Sleeves would make rebuilds much less expensive, not to mention simpler. Moreover, to have problems with sand casting at this point in history seems like they're dealing with people who have a serious lack of experience & expertise in the business. Not sure I would stake my life on that group of people.
 
Steel sleeves have some advantages but are heavier and have less heat transfer. Rotax 912UL at a similar price has Nikasil coated aluminum cylinders. As a comparison consider that after market VW Nikasil cylinders are more expensive than steel lined. There are some shops that can even remanufacture Nikasil cylinders.
 
Good Evening,

My apologies for the delay in my response, it has been a busy couple of weeks!

Fara:
Thank you for your post my friend and I appreciate the insight! I think the LF26 will be perfect for single seat gyros and I would like to install one in a SportCopter Vortex. I am curious to see what the installed weight of the LF39 will be as well. It will obviously vary slightly with the different aircraft applications. I am looking into the Little Wing LW5 for the 6 cylinder engine. I was looking into a pre-welded frame, however I work with stainless and mild steel tubing everyday at work. I have a couple of the welders interested in a group project, so we will see. I hope you are doing well and wanted to say that the new yellow AR-1 for Nick is gorgeous! That is one incredible AR-1 and Silverlight did an amazing job!

Eddie:
I believe D-Motor went with the flat head design to save weight and for its simplicity. It is an older engine technology, however a tried and true design. I have read somewhere that the four cylinder has only 35 moving parts. I think the four cylinder LF26 will provide an excellent competitor for the 912ul and Jabiru 2200. It uses the Jabiru/UL engine mount to make installation easier...

Eutrophicated:
They resolved all of the casting issues and removed the responsible parties from the company. From what I understand, the persons responsible were told it would not work, however they insisted on going with their design. This has all been resolved and from what I understand they are producing engines currently. The LF26 and LF39 are using Nikasil coated aluminum cylinders...
When a valve of an overhead engine is not closing, the engine stops and an expensive repair is the result. When a valve of a sidevalve engine is not closing, you continue flying with less power and there won't be the expensive repair cost. I believe they had the EDM co-axial helicopter in mind when designing these engine. Extremely simplistic and safe design...
You also get a lot of the accessories needed with the engine including an exhaust kit with lambda probe. These are a lot of the accessories needed that Rotax would charge you for. I am unsure about the valve overlap of the LF26 however will find out for you. I think overall the design is solid and am interested to see how the market will receive them. I am especially interested in seeing the different aircraft the LF26 will soon be powering in North America.

I greatly appreciate everyone’s input on the D-motor! I hope everyone is well!

Best Regards and Blue Skies,

Nicholas Dawson
 
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I have read somewhere that the four cylinder has only 35 moving parts. [/QUOTE said:
The parts I count:
4 lifters 4 valves 4 valve springs 8 Valve spring keepers 4 valve spring covers 1 cam 4 pistons 4 connecting Rods 4 connecting rod caps 8 connecting rod half bearings 1 crankshaft 3 crankshaft journal brng caps 6 crankshaft journal brng shells 12 rings 1 camshaft timing gear 1 crankshaft to camshaft timing gear 2 crank case halves 2 crankshaft seals 4 cylinder barrels 2 cylinder heads total parts = 74
 
It may be argued that some of those are not moving parts; by the same token, I didn't include any pulleys, belts, bolts, washers or idler gears. So I figure its a fair guestimate.
 
eddie;n1130439 said:
Its designed like an aircraft engine should be,large bore long stroke, low RPM and max torque @2,500 RPM and its fuel injected,

plus its direct drive and being liquid cooled,running in a pusher configuration wont be a problem either. Should be a great engine.

So, Eddie, do you consider the Rotax engines to be "Proper" aircraft engine designs?
 
Flynic3;n1131398 said:
Good Evening,

My apologies for the delay in my response, it has been a busy couple of weeks!

Eutrophicated:

When a valve of an overhead engine is not closing, the engine stops and an expensive repair is the result.

Nicholas Dawson

Actually, Nic, OHV engines have long been designed so that a sticking valve does not interfere with pistons or other valves. There are still a few engines still in production that would interfere, like the older Daihatsus. Of course on the off-chance that the valve face breaks off the stem, things will get jammed up in a hurry. Usually that only happens with engines revving past 10k rpm, because valve springs tend to allow for resonance floating beyond 12k rpm. That's why F1 engines "Had" to go to pneumatic valve actuation when rev limits reached 18k rpm.
 
Gents, Is there any information about somebody using these engines already since last year? I see that thread starter didn't visit the forum for a year already and I'm confused if this announced US-dealership for D-motors really works...
Wrote directly to manufacturer couple days ago - no response to the moment.
 
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