D-motor

[phvdw]

new boxer motor; lightweight

 

Kapelstraat 198 8540 Deerlijk - Flash Intro

 

 

[Yenn]

80hp from a side valve motor of that capacity is not bad, but it is a bit high revving for direct drive. The drive shaft looks to be rather long and I don't think it would stand up to side loads very well.

 

 

[xair1159]

The D-Motor is flying in an Xair Hawk (H or Hanuman) in the UK, a Standard Xair in France and another airframe in Germany. The UK engine has run about 200hrs on a dyno and 100hrs in the air, all looks fairly promising so far. Power is currently pegged at a genuine 80hp at 2800rpm, not over fast for direct drive and as hours build it is possible that power and rpm may be increased up to 3000+. Side valve may be old fashioned but gives a very compact unit with good torque and no breathing problems at the relatively low rpm. It fits on a standard Jabiru mount with an installed weight including rads, fluids, silencer etc. around 53kg. For comparison my Jab 2200 was a weighed 68kg for the same thing. If I can work out how to post some pics I'll put a few up.

 

Nick

 

 

[xair1159]

Hopefully some photos follow! The Hawk installation is still a work in progress and the final version will be suitably tidy. The engine was actually removed from the a/c for display at a recent UK show, which is why it is dripping oil in the fuel injection shot.

 

 

 

 

[xair1159]

Looks like on photo went missing! Try again later.

 

Nick

 

 

[geoffreywh]

Great looking motor. 2800 rpm is NOT too high for rev limit...My 0-200 is maxed out at 2750!....and it's Fuel injected/Water cooled too. 80hp is a little on the low side, cruise at 75% is only 60..Hp, That's not going to move any mountains. But fantastic (looking) design. What is it with Belgium and aero engines?

 

 

[Guest 4aplat]

A friend of mine try the engine many hours during fall

 

He told me that it is a very good engine

 

th final version will be available in january

 

MIcheL

 

 

[dazza 38]

Looks good.Always good to have another manufacturer, good for competition.

 

 

[Spin]

I'm with you Dazza, nothing like a little competition to keep the others honest. Watch a flurry of development activity if these are a success and they develop a conversion for 4 cyl Jabs:laugh:

 

 

[farri]

Neat and compact.If it`s as good as it looks,it will scare a few of the other manufactures.

 

Frank.

 

 

[facthunter]

Side Valves.

 

Side valve engines are not very efficient and have problems with distortion of the cylinder adjacent to the exhaust port. This causes blow-by past the piston and sometimes cracking of the valve seat or in case of an insert, in the metal around it and the insert coming loose.

 

The reason the engine is inefficient is the poor gas flow, particularly when high compression is sought. It is hard to get over 5 to 1 compression ratio. There is also a large surface area of the combustion chamber related to it's volume resulting in a lot of heat being lost. Specific fuel consumption would not be expected to be as good as an OHV configuration.

 

The engine is simpler and a fair bit more compact particularly in respect to width. Valve guides do not wear as much as they do not have rockers to push the valve sideways in the guides. It should be cheaper to produce.

 

I have done a lot of work with them over the years, including a "flathead" Ford Mercury that managed a water speed record before it blew due to getting the prop out of the water. The design belongs to another era , when petrol was cheap and the path to power was with Cubic inches rather than sophistication of the design.

 

The very early Lycomings were side-valves and they only produced about 45 HP. Some were built by the INDIAN motorcycle company, though they spelled it "MOTOcycle" in the early days. Nev.

 

 

[Guest 4aplat]

I'm with you Dazza, nothing like a little competition to keep the others honest. Watch a flurry of development activity if these are a success and they develop a conversion for 4 cyl Jabs:laugh:

the D motor firewall mount is the same as the jab so you woudld be able to switch the engines

 

 

[Guest 4aplat]

[xair1159]

Not a lot different to the latest 2010 model Comco Ikarus C42 with a long prop extension on another well known engine.

 

Nick[ATTACH]12652.vB[/ATTACH]

 

 

 

[farri]

That crank hangs out a long way in front of the crankcase. I see that as a potential problem with Gyroscopic precession forces do you? That would put leveraged forces on the front main bearing would it not?David.

Hi David,of course Gyroscopic precession from the prop would put forces on the shaft and the bearing,however,If the engine has been designed to withstand the forces, then there shouldn`t be a problem.

 

Comes down to the quality and strength of the materials used.

 

Frank.

 

 

[facthunter]

Prop extension.

 

Been away. sorry for not replying earlier, David.. Extensions are something you wear if you have to. I think the biggest problem is run-out. (the extension and prop do not run on centre, so out of balance loads).

 

The engine case has substantial webs. Lots of redrives look much weaker.

 

Gyroscopic precession used to break the cranks of the C-180 when croppies used to pivot them on ONE wheel at high revs. (fatigue, not overload). Nev

 

 

[geoffreywh]

I read news about the D-Motor. The first production run is being delivered. After some revisions the power is now 95hp, not sure what revs though. Flying weight is 124pounds including everything......! That is very light.....I'd have to lengthen the nose of the Jodel by about 3 foot. . Fadec controlled electronic ign. fuel injected..................... The six is also about to come online quoted at 135hp not sure what weight ? extrapolation gives 186 pounds that's about 50 pounds less than my 0-200! Bloody Jab 230 would go like you can't imagine!

 

 

[XAIRVTW]

http://www.recreationalflying.com/media/d-motor-d-motor-aircraft-engine-4-cylinder-flat-head-liquid-cooled-engine-from-d-motor-usa.289/

[dazza 38]

I like it. It reminds me of my Briggs & Stratton lawn mower. Being side valve.

 

 

[xair1159]

The initial production batch of 25 D-Motor LF27 engines are being delivered over the next month or so.

 

The D-Motor is currently being rated as 90bhp at 3100 rpm. All engines are run on a dyno before delivery and the first few have given around 93bhp.

 

The dry, bare engine weight is 46kg and the installed ready to run weight should typically be 56-58kg. Compare this to my own Jabiru 2200 where I weighed most of the major lumps and came up with an installed weight of 68kg for a quoted output of 80bhp at 3300rpm. The Jab has been reliable but disappointing in terms of power, although a top end and hyd tappet job at 350 hrs (1000hrs TBO?) did improve it a little.

 

I have flown an identical airframe to my own fitted with a D-Motor and with 10kg less up front and at least 10hp more there was a major improvement in performance for similar or better fuel burn. With luck I should be able to post some up to date photos and more details shortly.

 

Nick

 

 

[Old Koreelah]

The D-Motor is currently being rated as 90bhp at 3100 rpm. All engines are run on a dyno before delivery and the first few have given around 93bhp... I have flown an identical airframe to my own fitted with a D-Motor and with 10kg less up front and at least 10hp more there was a major improvement in performance for similar or better fuel burn.

Modern engine management technology seems to have given new life to an old design. I bet the D motor runs a lot leaner than we would dare run a Jab engine.

 

 

[dazza 38]

I posted a youtube video of this engine a few days ago.It is a video of a american man (with no neck) who I think is the importer into Nth america. I really like the design of the engine. I think it is about going to be about $4000 cheaper than a Rotax 80HP 912 .

 

 

[xair1159]

It's not just the modern management tech, although that will give optimum performance, but thanks to modern methods like CAD and flow simulation it has some very subtle design features which give surprising performance.

 

The side valve (flathead) design gave a flat torque curve at modest rpm, but the 180 degree airflow route into and out of the cylinders caused poor "breathing" at higher rpm. Not a problem for 3000rpm or so of a direct drive and the flat torque is ideal. Even less moving parts in the valve train and mechanically adjusted tappets, not hydraulic ones, plus it is very compact due to the lack of rocker gear.

 

The prototypes have done several hundred hours each in a variety of airframes, but it now needs service hours to get some credibility. Yes, I have one on order.

 

 

[Skee]

Im also looking on the D-motor for my ICP Savannah S, hows the status of your engine? i need references....