D-motor from Belgium

[WWhunter]

Anyone seen the new engine being sold through Renegade Light Sport Aircraft in Lees Summit, Mo.? 95HP and light weight with a 2,000 TBO. Saw it on my weekly Barnstormers email.

[t j]

It looks interesting. Priced too high for me to ever afford one though.
http://www.barnstormers.com/classified_712799_D-MOTOR++95HP+AIRCRAFT+ENGINE.html

[Geowitz]

Does look interesting. Initial drawback for me, at least specifically with the Kitfox, is that it is direct drive which would limit your prop diameter for our draggy airframe. That being said, on paper it looks like one of the best direct drive options(potentially without cooling issues) for the Kitfox.

[Av8r3400]

Flat head? Really? Wow.

[N714SM]

I saw that too. 125 lbs. "complete" including "exhaust, radiator and oil." With electronic fuel injection. The "low" price is good for the first 10 units sold. I wonder if it sounds like a Harley? NAH. Time to "Google" D-Motor. If it is a legit 95-horse it would have at least as much HP as a Continental O-200A. :confused:

[Timberwolf]

Same mount as a jabiru. 2.9 gal/hr 80 hp.

http://www.youtube.com/watch?v=wxK_GcZ3RSQ&feature=related

Weight sounds optimistic, as does the fuel flow.

[N714SM]

After further looking at the d-Motor (LF26) I'm finding it quite interesting. Especially interesting when you consider the d-Motor is a flat-head design. It just doesn't compare to those flat-head engines last produced by Detroit around 1953. First, the LF26 is a short stroke engine (bore 103.6 mm/stroke 80 mm). Wild. Vastly different from my Grandfather's 1950 Dodge!

Secondly, it is very high compression (8:1) compared to the flat-heads last produced. The last Ford flat-head V-8's may have been juiced up to about 7.3:1 or so.

It took some low-speed torque to get those heavy cars moving smoothly back then; hence, a nice LONG stroke to produce a torque peak of say, 1400 rpm.

What would be MORE interesting, though would some real-world thrust testing.

[Av8r3400]

I saw this motor run at Airventure. Intriguing to say the least. I don't think I'm sold on the "flat head" idea, yet. But it did look interesting.

Lets see a few out flying and a support network established here in the 'States and we may be able to talk....

[Danzer1]

This one was also on my preliminary engine list, so I've checked into it a fair bit. Clarification of a few things already mentioned:

D-Motors site indicates a 1500 Hr TBO not 2000 and a 300 HR warranty.

The 125 Lb weight includes the oil radiator but not the cooling radiator or associated piping and mounting hardware. None the less, it still seems light, which makes me wonder if some internals have been reduced in weight which might affect longevity/reliability. I'm not willing to be the PAYing test pilot to find out.

The current price is 12,600 Euros plus 125 for crating plus shipping to you. So at today's rate 12725 Euros = $17,250 plus shipping from Belgium.

D-Motors HP & Torque curve are in metric units - DIN HP and Newton Meters torque. Factory rated at 91.7 HP @ 3000 RPM. This equals 90.5 US HP and 158.4 Ft Lb of torque at 3000 RPM. (Not very torquie - new word).

Also their site states "max" at 3000, but does not say you can run it there or if you can, for how long? They state 2800 RPM continuous. Which is 87.5 HP (US) and 164.1 Ft. Lbs of torque. Still not very torquie!

Fuel consumption is listed as 12 L/Hr (3.17 gallons per hour) at 75%. So is that 75% of rated or 75% of max continuous?

75% of 3000 = 2250 = 68.4 HP US and 159.7 Ft Lb torque
75% of 2800 = 2100 = 60.3 HP US and 150.8 Ft Lb of torque

This is a direct drive motor, so the engine rpm's are also prop rpms. In other words - you don't get any increased torque available as you would with a reduction drive/geared motor. It is what it is.

So it seems conceivable that it could be sipping fuel at those numbers. So the real question is, are those numbers high enough to get you where you want to be, when you want to be there - the way you fly?

Would be nice to see the full fuel flow data - one point is not enough to draw a line, no less a curve, so their single point is pretty useless. They had enough data to plot hp/torque curves - yet only publish a single fuel flow point - why do manufacturers do this? Every dyno I know of pulls the fuel flow numbers at the same time - so why don't they give them to us?

Anyway, this ones not for me either. But the LF39 6 cylinder that is in the works might. That one is not as far along though and I'm still not willing to be a paying test pilot for any engine manufacturer.

I touch on all this, because mostly what I hear is "rated HP" and it really doesn't matter! It is always at an unusable point in the curve and never close to where anyone is going to fly it anyway. Torque@rpm/fuel flow/prop diameter/prop pitch/LD ratio/altitude density - lots of real important variables & HP isn't one of them!

So, I'm still evaluating power plants.
Greg

[N714SM]

I have been watching the dollar get handed its lunch by the Euro slowly but surely over the last year. Not good.

D-Motor is quite the enigma from a marketing perspective. It's easy to get the impression that there is almost no interest in selling those things over here -- perplexing at best. BUT if you call or email Doc he will be happy to discuss the power plant and even provide you with some very interesting info you couldn't possibly find on the internet.

I like the idea of cooling cylinders with water. It works much better than air. :rolleyes:

[Danzer1]

I too have been watching the dollar sink to the Euro, but because I am interested in the (still more expensive) UL 315is. Hopefully the cycle will reverse and towards the end of 2014, I'm hoping it will be much more reasonable.

As mentioned before, I threw the LF 26 out of the mix for my consideration as it simply doesn't have enough UMPF for me. However the LF 39 does and compares very closely to the 315is.

That said, I have looked further into the D-Motors and still have the following concerns (applies to either D-Motor):

Weight; I know virtually all manufacturers don't include all of the items required to operate an engine in their weights listed. Knowing that, I still can't see an operating weight near 125 pounds. Maybe for the core engine "with liquids". But this also has a radiator, oil cooler, oil reservoir, cooling reservoir, ecu and fuel pump, all mounted separate from the engine. I'd really like to see some users post actual firewall forward installed weights - my guess would be between 150 and 160.

Extended testing/reliability: There is still very little info about the LF 26 in operation and virtually none on the LF 39.

The above being important (besides the obvious reasons) because - after looking past the cool flat head design - it finally dawned on me that the INTAKE IS MOUNTED ON THE BOTTOM of the engine!

Has anyone ever seen a bottom mounted intake? If so, I'd like to know how well and how long they worked. Anyway, I've never seen one and so (being an ex engineer) it got me wondering - what could go wrong there?

Hmm:

It's next to and above the exhaust and muffler - MIGHT add some heat to the intake air - never good for efficient combustion. Maybe negligible though.

D-Motor says and I quote "When a valve of a sidevalve engine is not closing, you continue flying with less power and there won't be expensive repair cost"

What happens when the rings, valve seals etc. break in and over time wear and allow oil seepage? Where does that oil go? Where does the oil and/or water go if a gasket fails (head or intake)? Or head or block crack? In a conventional top mounted intake - it mixes fluids till it overheats and/or drips off outside the case and keeps running until there is not enough fluid left and/or it overheats and then it fails. IF water and/or oil can get into the bottom mounted intake (likely as there is a direct path) - I'd bet it would stop running pretty quickly.

So, I'd really need to see an extensive amount of time built on either of these engines before investing in one.

Just my 2 cents!
Greg

[Av8r3400]

The above being important (besides the obvious reasons) because - after looking past the cool flat head design - it finally dawned on me that the INTAKE IS MOUNTED ON THE BOTTOM of the engine!

Has anyone ever seen a bottom mounted intake? If so, I'd like to know how well and how long they worked. Anyway, I've never seen one and so (being an ex engineer) it got me wondering - what could go wrong there?

It's next to and above the exhaust and muffler - MIGHT add some heat to the intake air - never good for efficient combustion. Maybe negligible though.

Most certified reciprocating engines use an updraft induction system with the intake and exhaust below the engine. Lycoming engines even route the intake runners through the oil sump, with the carburetor bolted directly to the sump, to heat the intake charge lessening the likelihood of induction icing.

http://www.aero-news.net/images/content/genav/2013/Lycoming-O320-0413b.jpg

I took a long look at the D-motor at Airventure this year. It is a very interesting motor, to say the least, but I also am very skeptical on the efficiency of a flat head design in regard to combustion. Flow and swirl are major considerations on a reciprocating engine. If flat head motors weren't so inefficient, they would still be in use in the automotive industry.

[Danzer1]

Guess I should have been clearer - it's the bottom mounted intake without an oil sump that concerns me. All of the certified ones had an oil sump to collect the gravity flowing oil. This doesn't, it is a remote mounted tank firewall mounted higher than the engine, so the intake system is the only place for it to go if there was a failure/leak/seepage.

[Av8r3400]

http://www.homebuiltairplanes.com/forums/attachments/firewall-forward-props-fuel-system/2010d1219454301-engine-dc-electrical-advise-sm-aug-18-2008-w-airbox-2-.jpg

Continentals are separate…

I guess I don't follow what you are thinking. If there is an oil control failure and the oil gets past the intake valves, it will go into an updraft induction system no matter the location of the oil sump.

The Rotax 912 uses a dry sump system. The intakes are on the top, so there is no place for the excess oil to go in the event of an oil control failure (extremely rare - but possible). One of the reasons for pulling a few blades through to burp the motor before starting, making sure there is no hydro-lock.

[Danzer1]

Larry,

Many Continentals have a sump, it looks like an o-200 you are picturing and even that has an oil reservoir below the engine. Are you saying that if oil were to get into an intake (leaky valves and/or rings) without another place for gravity to take it - the intake could simply ingest the oil and run?

You wouldn't have hydro lock as the cylinders are on the sides and gravity wants to take the oil to the low point - in the case of the D-Motor the valves are under the cylinders and the intake below that, which is also the low point - not a sump or reservoir.

As you mention on the Rotax the intake is on the top and the valves are also above the cylinders, so if they leak, everything should leak down past the pistons, through the cylinders and into the crankcase.

The primary reason for cycling a Rotax was/is to get the oil out of the crankcase as some filters did not have anti drain back and many builders were mounting the oil reservoir to high in relationship to the engine and without burping, it was impossible to get an accurate oil level check. IE, pre-oiling to get the oil out of the crankcase and back into the tank. Not specifically for hydro-lock (although it does check for that) which is not very likely on an overhead valve, side piston engine. Not like could occur on a radial where the oil could be on wrong side of the bottom cylinder head.

But back to my point: if there were a water and/or oil breach (internal gasket leak or head or block crack) where the intake is the lowest point in the system - couldn't the oil and/or oil-water combination drown the intake and kill the engine? And in this case with the valves under the cylinders - drown them out first before it even gets to the intake?

For example most auto engines have the intake on the top - coincidentally, just last week (which got me thinking about this in the 1st place) my wife drove her car for over 2 hours with an internal head leak (crack) due to a stuck thermostat, that flooded the cooling system with oil which then overflowed the cooling system. To my surprise the engine was running fine when she got home. It was noticed because the volume overflowed the cooling tank onto the garage floor and the puddle wasn't straight coolant! It had pumped over 2 quarts of oil into the coolant side. But it certainly still runs even with fluids in the wrong place. I don't think that could have happened if the intake was under the engine and ingested (either from an internal breach or externally) that volume of oil/water.

[Danzer1]

Okay, here's a picture of the inside of a D-Motor head:
5981

The exhaust and intake use a common chamber BELOW the cylinder. The intake is below that. There are plenty of ways for water or oil or a combination of both to get into the intake and effect all cylinders.

Granted a failure in any engine is not a good thing, but as mentioned, with the valves above the cylinder and also the intake above it all - there are many times in a more conventional engine, that the failure only affects the one cylinder and you can continue to run on the other three.

Not saying it would in this case but the chances are vastly increased by the location of the valves and the intake orientation to the cylinders.

Also might want to note the location of the spark plugs. In this case they are opposing the cylinder case in the intake/exhaust passage, between the valves and the cylinder. This type of design was one of the reasons flat heads produced less power (more power wasted to exhaust) than a conventional design with the plug centered above the cylinder.

It required lower compression to avoid burning cylinder casings, valves and valve seals. To avoid this problem the compression was generally less than 7/1. D-Motor indicates an 8/1 ratio which MIGHT also be a long term longevity issue.

As mentioned with this design, I would want to see an awful lot of history before investment.

[Fox Pass]

This is great, for many years I've watched cars get more and more stream lined and wondered why the flat head was over looked. Now that I've gotten serious about aircraft the compact sizing of flat heads seemed obvious.
Throw modern engine tech at the flat head I've often though that a lot the problems of the flat design could be overcome. This will be fun to watch.
James.

[Danzer1]

James,

That would be interesting if it were the case, but everything with this motor except the electronics is 1930's technology and design. Flat heads were less efficient due to the design and I don't see that changing here. The upside down layout is not helping me gain any additional enthusiasm for these engines.

Greg

[Fox Pass]

Darn it!!!

[SWeidemann]

Getting back to the D Motor...does anyone have more new information? Since the HKS four stroke series seems to have been eliminated as a possible engine source, the D Motor has come up again. After an Internet inquiry, I got a call from Doc in Deland who gave me an enthusiastic pitch. D Motor will be at Sun N Fun, so we can take a look. Apparently there are plans to manufacture these engines in the States.

Does anyone have plans to install one of these motors on a Kitfox?

Skot

[Micro Mong Bldr]

One nice thing about a flat head with the valves below is that if you break a valve stem you'll usually lose 1 cylinder but no other damage is caused, unlike an OHV where you get wholesale destruction of the engine.

[LSaupe]

Thought I would chime in on this engine. Its been a few years. Anyone have any updates on how these engines are working out?

[Micro Mong Bldr]

Death of the HKS has been greatly exaggerated! If you get one be sure to go for the 3.47:1 gear box, not the 2.58:1.

[joecool]

My name is Jose "JOECOOL" Ruiz. D-MOTOR update. My D-MOTOR from Belgium was being build this past week. Jan. 27th through Feb. 1st. 2020. There was a delay in manufacturing due the company moved to a
new building with more room for production. Hope it will ship from Belgium soon. It's supposed to go to Canada first to Fisher Flying Products then to Texas. Hope to post more updates soon....thx

[joecool]

Howdy Kitfox brothers!
My D-MOTOR is now in Canada at Fisher Flying Products. It arrived sometime this week
and they will ship it as soon as they can. Considering this virus thing and all.
I wish I knew how to post Pics on this site. I am so tech-not-knowing.
Will update again soon. Today is Saturday March 28th 2020. Stay safe and wash your hands.

[SWeidemann]

Howdy Kitfox brothers!
My D-MOTOR is now in Canada at Fisher Flying Products. It arrived sometime this week
and they will ship it as soon as they can. Considering this virus thing and all.
I wish I knew how to post Pics on this site. I am so tech-not-knowing.
Will update again soon. Today is Saturday March 28th 2020. Stay safe and wash your hands.

Joe,

Glad to hear. Looking forward to knowing how it goes as well as the future of the engine. I understand the HKS has been halted again.

Skot