D-Motor

[M61A1]

I didn't even go near roadbikes such as and especially the Suzuki GSX-R range that blew everything watercooled away for many years and gave huge bulletproof service life to everyone that owned them. Alas, for emissions control they had to go to water cooling for tighter bore clearances to comply with exhaust emissions at cold start up - and they got heavier and slower while doing it and took years to get back to the same weigh and power levels, it's well documented.

Hi Bex.. Wasn't the GSX-R oil/air cooled? The earlier GSX were 100% air cooled if I recall correctly?

 

Cheers

 

Vev

 

I have a couple of old GSXRs, they are oil/air cooled, having a stage on the oil pump that pumps high volume oil over the valve and combustion chamber areas. It has a reasonable size oil cooler as well. From memory they went to liquid cooling around 1992, and in the process, put on a lot of weight. The original GSXR 750 in 1985, was around 175 kg and 100 hp. It's GSX predecessor was your usual run of the mill air cooled machine of the era.I've sometimes wondered how a GSXR engine might go as an aero engine, using the secondary drive gear to turn a prop, but removing the gearbox internals to reduce weight.

 

 

[geoffreywh]

being produced as we speak. French company, looks very competent...they leave the clutch in an some gears too

 

 

[bexrbetter]

It's GSX predecessor was your usual run of the mill air cooled machine of the era.

Usual? They were so good today they get them to 1600cc and all sorts of competition such as sidecar racing and about 800hp for drag racing on nitro!

 

I've sometimes wondered how a GSXR engine might go as an aero engine, using the secondary drive gear to turn a prop, but removing the gearbox internals to reduce weight.

I proffer that you would leave the gearbox on and use 2 sets of the one gear ratio on the shafts for strength, most bike boxes allow for this.

 

 

[M61A1]

Usual? They were so good today they get them to 1600cc and all sorts of competition such as sidecar racing and about 800hp for drag racing on nitro!

 

I proffer that you would leave the gearbox on and use 2 sets of the one gear ratio on the shafts for strength, most bike boxes allow for this.

I know that they get similar HP numbers from hayabusa engines, but I was unaware that the used the old GSX motors from the early eighties. When I say "run of the mill", I mean that they were everywhere.

I'm no mechanical engineer, but, I can't see how using the original gear shafts will make it stronger. My idea was to run the prop shaft through the existing bearing tunnel of the gearbox input, and use the existing secondary gear(the one on the clutch), as my reduction. The alternator and oil pump are driven off the same gear, so it makes sense to use it for simplicity

 

 

[bexrbetter]

My idea was

Yes, I know what you meant, you will enjoy this article I'm sure ...

 

http://www.motoiq.com/MagazineArticles/ID/1519/Project-MiataBusa--Part-1-What-The-Hell-Are-We-Thinking.aspx

 

 

[geoffreywh]

http://www.vija-engines.com. try this one ..................looks delicious....

[bexrbetter]

http://www.vija-engines.com. try this one ..................looks delicious....

Yeah great memories, GXR750R first 145knh and a then few weeks later 150kmh and 6 months no licence - Ipswich Motorway

 

Oh and there's a 650 twin here of the same ilk (Kawasaki copy) that's just coming onto the market here, might make a good thing for aero.

 

 

[JabiruWeekendWarrior]

Anybody have any new word to share, on the progress and flying examples of the D motor ????

 

Are there many flying in Australia ??

 

 

[Greg Spiers]

Anybody have any new word to share, on the progress and flying examples of the D motor ????Are there many flying in Australia ??

Look up [email protected] The distributor is Adam Nagorski D-Motor Australia P/L. I know one engine is flying in Australia (his I think) and another either here or on the way, Adam will gladly tell you I am sure.

Greg

 

 

[Gentreau]

There's info on his website too.

 

http://www.d-motor.com.au/photos.html

 

 

[Guernsey]

Good to see that we are back to discussing D motor.

 

Alan.

 

 

[facthunter]

Don't say sorry. You are right. Nev

 

 

[Gentreau]

At the Blois air show last weekend, I had a flight in the X-Air Hanuman powered by the D-Motor and found it very smooth, lots of spare power and very responsive.

 

So far everything I've seen regarding D-Motor says quality and professionalism.

 

 

[Virago]

I see on the D-Motor website, one has been supplied to Morgan Aeroworks for installation into a Cheetah in place of a Jab 2200. I will be real interested to see how that pans out. Any comments Garry or Tim?

 

 

[Guest douglish]

Saw one mounted on a dummy fuse at GOSH this year, driving a flywheel, the guy was starting and stopping it on request. Sounds good, not deafening, having cut my teeth with side valve Ford Prefects and Morris Minors, I thought the concept was great for its simplicity.

 

 

Most of you have to read a book to find out what a side valve is, but every Ford V8 up to 1949, was side valve. WW2 Jeeps, and Dodge 10 wheelers. Same for all Dodge - Plymouth cars and Trucks to about 1956 or so.

 

Don't run in terror from something you know nothing about, ask your Daddy or Grandad. Might not have extracted as many HP per cc, but ground on and on forever. Low revving, reliable, dependable, no flashy acceleration, just runs. 'Scuse me, sounds great for aircraft. Anyone know where I could get an aluminium Morris motor? Aw-Unh-Was Al invented then? Lets all watch and see, without making great pontifications one has to eat in six months. If it is underbuilt or overstressed it will go the way of........

 

 

[Old Koreelah]

Looks great! Like you say, just about ideal for aircraft.

 

Have a look under some 1920's cars and you will see enormous aluminium castings. The stuff has been around for yonks, but car builders found iron cheaper and more reliable.

 

 

[Yenn]

Everything old is new again.

 

The side valve was very common and i have spent many an hour working on them, in the same era were crash or constant mesh gearboxes, univacs instead of fuel pumps, vacuum windscreen wipers and a host of other things. Why did they become superceeded? Because they were not efficient. I don't know what the horsepower per litre was for side valves, but it was a lot less than OHV. The old Ford V8 used to sound great, but I wouldn't mind betting that a 125cc motorbike nowadays produces more power and weighs a lot less.

 

 

[facthunter]

No 125cc motorbike engine will pull a FORD V8 car body around. The SV was compact and simple and another the Hudson Terraplane of about 2600cc made 110 horsepower. with primitive manifolding They were used in hillclimbers and many specials. The very early 45 horsepower Continentals were two bearing SV engines. Some were built under licence by the Indian company. I helped build one particular Ford SV that broke the Flathead water speed record in the 50's Sid FOGG owned the boat. A Newcastle bus company. was his business.Nev

 

 

[Keith Page]

Everything old is new again.The side valve was very common and i have spent many an hour working on them, in the same era were crash or constant mesh gearboxes, univacs instead of fuel pumps, vacuum windscreen wipers and a host of other things. Why did they become superceeded? Because they were not efficient. I don't know what the horsepower per litre was for side valves, but it was a lot less than OHV. The old Ford V8 used to sound great, but I wouldn't mind betting that a 125cc motorbike nowadays produces more power and weighs a lot less.

Good morning Yenn

We are chasing torque in our ittle planes not developed horse power, when we get developed horse power there are reduction boxs involved hence more moving parts.With these slow revving D-motors we are on a winner as the fuel burn is less for torque provided.

 

There is a very good article about " Torque verses Horsepower".

 

Regards

 

Keith Page

 

 

[facthunter]

IF you want to keep it simple direct drive is the way to go. Side valves do not flow gas as well as OHV but are far more compact (less height above the piston at TDC) They have a few other aspects to them but this concept may prove very workable as a liquid cooled motor. They often work better as a longer stroke motor particularly where you want torque without revs. They cannot run high compression without losing gasflow even more. Sometimes they are promoted as having more torque than an OHV. This is not the case if the OHV is low compression as well and longstroke. Nev

 

 

[geoffreywh]

Look how narrow that bugger is! It would suit skinny tandem seated aircraft so well ( or single seaters). A well designed aircraft would not have to be any wider than two feet!

 

 

[facthunter]

The widest part would be where the pilot(s) are in a tandem seat . The inverted in line were the only ones narrower. Nev

 

 

[Oscar]

The D-motor is certainly interesting. However, and as in so many cases, to get the best result from using an engine, the aircraft usually needs to be designed around it. Years ago, Phil Ainsworth wrote an article for the USyd School of Aeronautical Engineering outlining just why Jabiru decided to design their own motor when the KFM engine ceased to be available: it's really worth a read: http://www.aeromech.usyd.edu.au/AERO1400/Jabiru_Construction/jabiru.html

 

For an aircraft to be an efficient package, a whole mess of intermeshing factors need to be considered and integrated. Just comparing a few things such as weight and output (hp and torque) will not necessarily point out that an engine swap will bring about an increase in overall operational efficiency (though it MAY bring about a substantial change in one or two performance areas). For instance, W&B considerations over the whole flight envelope can mean that an apparent saving in engine installed weight (for instance) may not result in a similar improvement in usable weight.

 

Then there's the cost factor. An expensive engine may offer some significant advantages; let's look at a Jab. 2200 vs D-motor. Let's assume from the discussion above that the D-motor in a Jab. could give the same performance at say 10 litres/hour vs. 16 litres/hour for the Jab. 2200. That's a saving of 5 litres/hour, or say at current fuel prices, what? $10/hour max.? The average private owner of a Jab. 2200 probably flies say 100 hours/year. Actual statistics suggest less, btw).. At the rough cost difference for a new Jab. 2200 vs the D-motor, it will take around 8 years to recoup the additional cost - assuming that there is NO additional cost for installing the D-motor in place of the Jab. (same cost for prop., engine mount, ancilliaries etc. - never mind the possible costs of engineering, flight testing etc. for the change-over).

 

Now, let's look at a realistic scenario: you have a J2200 engined beast - let's say for the sake of simplicity, an LSA55 or J120 or 160. You have a 300+ hour Jab. 2200 engine and you have a reasonable concern that it is going to require a rebuild soon-ish. Should you consider replacing it with a D-motor?

 

Well, you could go to CAMit and buy a CAMit rebuild engine for ( I believe) something like $9k - $10k with the 40-amp alternator conversion included. ( http://camitaeroengines.myshopify.com/pages/new-camit-aero-engines ) Yo install that, bolt on your existing prop, re-do the W&B and continue flying. You could change over to the D-motor, for $21k purchase price, plus a new prop, an engineering certificate and flight testing - conservatively, $24 -$25k before you leave the ground. That's around 12 - 15 years of flying before you break even. I note from the D-motor site that they anticipate 1500 hours TBO, but offer a warranty for 300 hours. Does 300 hours sound familiar to Jabiru 2200 engine owners?

 

Then, perhaps you should look at back-up. If D-motor is not a commercial success, you could be left with an orphan installation ( see: Diamond aircraft..) Jabiru have something like 5,000 engines sold. That's a pretty solid customer base - and most of the important parts are manufactured right here in Australia (by CAMit).. They're a few days away from delivery by AusPost or courier service.

 

The D-motor in an aircraft designed to maximise its potential and with a solid commercial base behind it, is without doubt a very interesting development, very worthy of solid consideration. I have long had in mind a twin-boom single place pusher, of somewhat similar concept to the Taylor Imp, as a fun blast-around aircraft and the D-motor could be just the ticket for that. But for my wee Jab,. I'll stick with a Jab.-based engine wheeled (well, carried, actually, by me and my co-owner of our wee beastie) out of CAMit. And I expect 1K hours out of it before it even so much as hiccups.

 

 

[xair1159]

Oscar,

 

A well reasoned post and I would agree with much of it.

 

However you base it on the fact that Jabiru are local and easily contacted, which is certainly not the case here in Europe. I used a Jabiru 2200 hyd tappet engine for several years which was fairly reliable but sadly lacking in power. Attempts to contact the factory with any queries were a waste of time and the local dealer is expensive and doesn't have a great reputation for customer relations. I would guess that now Camit are setting up as an alternative source they could be easier to deal with, but the Jab engine could yet become an orphan over here. The warranty was basically worthless with any and all problems blamed on the owner, installation, maintenance, the way it was flown, the fuel - anything but poor design or quality control.

 

Given the above you can see why this side of the world D-Motor is more attractive, plus I have visited the factory and was convinced it is a solid business and the guys are in it for the long haul. I was impressed enough to buy one to replace the Jab 2200 and have 33 hours on it so far with zero oil use between changes, found it surprisingly easy to cool and with a lot more power. Early days in terms of meaningful TBO etc. but I am quietly confident as they say!

 

Nick

 

 

[Oscar]

Nick - more than fair enough! Jab. engines certainly have their problems, nobody denies that, and my reasoning was entirely based on keeping or replacing a Jab. engine in a Jab. airframe - and in Australia, obviously. I think the D-motor has a lot of good features and thoroughly deserves to succeed, where some other attempts have been skating on thin ice from the outset. Basically, it comes down to the old adage that one gets nothing for nothing and in terms of selecting the right engine for the job, the equation is frequently complex: cost vs quality and reliability, weight, power,fuel consumption, cost/hour maintenance etc. Simply looking at one or maybe two of those factors and apparently seeing an advantage between two different engines often isn't the whole answer.

 

Good luck - and your experiences with the D-motor will be good to know. It's real-life use results that provide real guidance, not just the figures on paper..