D-Motor 6 cylinder running...

[Syd]

Am following the development of this motor with interest... they have the 2.7 litre 4 cylinder rated @ 95hp in production now with engines on the way to the US and to Australia...

And they have just run the 6 prototype which is a four litre, 60 degree firing order with one wasted spark..... direct drive engine est. 125- 135hp @ 3000... fuel injected flathead motor.....

Less than 80 kilos installed, probably around 75 - very small dimensions...

I have been in communication with Alain @ D-Motor and he sent me this in an email reply to some questions....

We also plan to develop a version with 2 separate intake collectors and 2 separate admission valves. This version should be more powerful as the standard version because we have better intake flow and we can make intake pipes longer.

... now that would be fun.... similar specs delivering 140-150 hp would make a very cool highlander SS install...

I am hopeful that the engine will meet expectations and a suitable timeframe for me... my SS kit arrives in Sept/Oct...

Check out the website...

http://www.d-motor.eu/nl/update-18-june-2013-95.htm

[Augustus]

Interesting post. I had to bite.

I have looked quite a bit at the "95 HP" D-Motor. Their website kept saying it was 80 HP which conflicted with a local dealer's claims of 95 HP. Anyway it is an interesting power plant and an interesting concept.
I remember my grandfather had a 1949 dodge with a flathead six which was incredibly quiet. Lots of iron surrounding the valve train resulted in little "noise." Of course weren't not that concerned about valve train noise these days especially in an aircraft. Just an observation.

Thanks for the post.

[Syd]

I think that the original design for the 4 was a 2.5 litre rated at that 80hp. I think that they stroked the original design and swapped the new design for any existing 2.5s that were flying... the new design rated at 95hp..

The 4 is really lightweight....

[Augustus]

This is really a post about the d-Motor LF-26 (4-cyl). I'm wondering how the take off distance and rate of climb would suffer if you replaced a) a 100HP Rotax or b) an 80 HP Rotax (in a SuperSTOL) with a d-Motor LF-26. Assume your prop is optimized for climb and especially ASSUME the published figures for the LF-26 are accurate: 91.8 max HP @ 3,000 rpm and 162 ft-lbs. of torque @ 2,500 rpm.

The Zenith website publishes the specs on two different (draggy) CH-701s with engines whose HP ratings differ by 20 HP. There's not a whole lot of difference in the TOR distance (+25 feet)and ROC (+100 fpm)between the two engines. http://www.zenithair.com/stolch701/7-perf.html

Would some please take a stab take-off roll and rate of climb using a d-Motor LF-26 versus engines a) and b) above?

After watching Steve Henry's video for a few times?

Please?

[taildrgfun]

I realize that I'm pretty spoiled with my motor but there is no way I would put anything less than a Rotax 100 hp. in a SS.

[Augustus]

Thanks for the reply, Steve. When I wrote that post I figured it was of the type that dies a lonely (unanswered) death in cyberspace. Oh yeah and thanks for posting those wild videos!

[moving2time]

I have also been following the D-Motor progress and all I can say is that following these newer engines as they develop and move to market is like watching glaciers move! The simplicity and weight savings the D-Motor offers are both very appealing attributes of the D-Motor. The one thing that is a little disappointing is that the conceptual fuel consumption for the 130HP six cylinder D-Motor is a little higher than I would like to see. The first thought I had was, could a four cylinder version be built that would produce 130HP and would it use less fuel. I actually wrote D-Motors and asked this question and they replied that 4 cylinders at 4000cc's producing 130 HP would use the same or more fuel as 6 cylinders at 4000cc's producing 130HP. I never thought of it that way but it makes sense. I guess no matter what engine we find that will produce more than 100HP we will use more fuel than a Rotax producing 100 HP. The UL360 uses more fuel than the 100HP Rotax but again it is a bigger displacement engine, so is the six cylinder Jabaru. Turbo boost seems to offer more power for the displacement but how does it affect the fuel consumption? Perhaps Steve can answer the question of how the Turbo boost affects the fuel usage since he has a direct experience comparison. The turbo boosted Rotax is a much more complicated power plant and that isn't appealing. I'm learning more about power plants all the time. The fight between power, fuel efficiency, weight, and simplicity just never ends but it is fun to study the variations that are being investigated!

[taildrgfun]

It seems that fuel burned is pretty much proportional to the power produced with my turboed Rotax. Somtimes I burn 4 gph but I have burned as high as 8 gph when I just wanted to get somewhere and was not worried about economy. Earlier this year when I flew my SS to Arlington before covering the gear or shocks or anything, I flew 100 mph burning 8 gph with 26" tires. About a month ago I flew it to Copperstate @ 100 mph using just over 6 gph with 29" tires.
When I really like all the power is when I am taking off from some wild place and I sure don't care how much fuel it burns for a few seconds.
There is no denying that these are expensive, complicated engines but they are worth it to me for the power when I want it.