Here are some pics,

I don't think there is anything "secret" about it lol

http://f3a.sakura.ne.jp/radiocontrol...bbyShow01.html

Its looks to me a simple hall (mag pickup) sensor in in the backplate, probably picking up a mag source on the crank pin.

I recall reading something about the disc valve being replaced with an aluminium version. I guess the crank pin is the logical choice for the magnetic source.

From what I have read this development sounds too good to be true. It will probably force some electric flyers back to glow unless lipo flight packs take a sudden drop in price because the running costs of a DZ170 CDI will be halved. Very exiting to say the least

They may have replaced the disc valve with AL to make the mag source for the sensor more visible....and to save some weight at the same time

Switch back to glow.....not unless FAI bans electrics from competition There are guys playing with some packs that are 1/3 the cost of name brand stuff, we will see how they hold up though.

This looks amazing guys. I want one now! Where do I sign up??

Joe

Here are some pics of the conversion from a Japanese website [link]http://www1.plala.or.jp/konchan/170CDI.htm[/link]

Actually, I am sure CH Ignitions could make up a system like that. They used to convert glow engines back in the late '80's, I still remember the ads in RCM.

Be aware, however, that spark plug they are using on the 1.70dz is EXPENSIVE and fragile.

H'mmm. 60 years of progress in technology and we cannot build a reasonably priced and rugged sparkplug? Maybe someone should bringback the Champion VR2(?) or VR3(?) from the 40's. Very good plugs that worked well even with the old simple coil and condenser ignitions systems on 3 volts.

John W.

[/quote]

H'mmm. 60 years of progress in technology and we cannot build a reasonably priced and rugged sparkplug? Maybe someone should bringback the Champion VR2(?) or VR3(?) from the 40's. Very good plugs that worked well even with the old simple coil and condenser ignitions systems on 3 volts.

John W.
[/quote]


It's time to bring back those big toss away cylindrical Eveready batteries for the glow plugs again ...

There are lots of cheap, reliable spark plugs out there. But none of them fit into a glow plug hole...[:@]

The problem is the plug is the same size as a glow plug and is a small volume, niche market item. I believe someone on the Gassers forum mentioned they are around $15 each. I have no idea how long they last. Maybe Bill can report his results on the 170?

Mark

$15 is only about twice the cost of an OS 'F' plug or the YS equivalent. How long do they last (# of flights on average) in a DZ? It seems a sparkplug would last a lot longer than a glowplug which has a pretty fragile element that has to 'glo' continuously for the duration of the run time where the spark plug is only 'firing' once every other revolution. Very interesting engineering effort on the part of YS. I wish I could buy an engine ignition device for my car that would double the mileage!!!
-Will

Spark plug cost? None of them fit the glow plug hole? No problem.

You can buy these 1/4-32 spark plugs all day long for $17.00 each. They have been around for over 60 years! Made right here is the US of A. On 30% fuel using 1/2 to 2/3 the fuel a standard glow plug engine would use you could buy a new plug every 2 gallons of fuel due to just the fuel savings, crazy argument. I have not needed another spark plug, still on the original, just checked the gap after 120 flights and no measurable change. You will go through a couple glow plugs to every spark plug, but I have not used up a spark plug yet so I do not know the true life limit yet. The quality of idle and transition on a glow plug engine is dependant on the element being in good shape and not covered in, what I call "frost".

I have a C&H ignition, the problem is getting the magnet into to the hub using a nose ring. Being internal as YS did it makes this a non issue and consealed.

Bill

The plugs are not fragile in use, but they are fragile to handle. That is what I meant. The 1/4-32 plugs are readily available, as Bill mentioned.

Is the mag placed into the cam? I wonder how to properly set the timing on a 4 stroke otherwise. Don't want it firing on the wrong stroke!

I know CH has converted many 2-stroke and 4-stroke glow engines so they must have a method.

Will, your car's computer already does this for you.

If your car ran on glow methanol and you converted it to spark on methanol you would see a similar increase in mileage because you could lean the mixture without risk of detonation.

Methanol can tolerate a wider stoichiometric range than can gasoline before autoignition occurs.

I just went back and reread Bill's original post. I didn't realize YS was going to start selling this retrofit. I thought it was a one-off, which is the reason I mentioned trying CH Ignitions. Sorry for the confusion!

Bill, do you know anthing about the timing curve of the EI system? I assume it has retarded timing at lower rpm, advancing as the revs increase. My big gas planes are wonderful to start and won't backfire because the plug won't fire until the piston is travelling downward (I think it fires at 2* after TDC, and advances to 28* BTDC after about 4000 rpm).

The 600 rpm idle and low fuel consumption sounds phenominal!

stoichiometric now thats a big word!!! lol

gary

Almost all of the electronic ignitions on the market today use very close to the same program curve and it is in relation to the RPM. Idle needs to be in the 7 degree BTC range otherwise the idle is really rough. Full advance on the model engines needs to be 28-30 degrees. Anything outside of this brings in to many other issues and the power gain is just not worth it.
Back in the TOC days I worked with an ignition that would pull back to TC at idle trying to get the downline speed slowed down but the engine would start to backfire and sounded really bad, breaking was good.
The YS fires every revolution since the magnet pickup is in the rotor disk, the current draw could be cut in half if it did not do this but battery consumption is so low its not an issue. The ignition is powered by the flight pack battery.

I dont think I said 600 RPM idle, it does idle at 1400 very well.

Bill

Yes of course your post says 1400 rpm. It was papaone who said 600 rpm. My mistake.

Still, that is exceptionally good. I assume the throttle response is amazing.

If the plug fires on every rotation, that certainly makes things easier from an electronic standpoint. That probably wouldn't work on a gasoline engine as any unburned gasoline could reignite and burn in the exhaust system. I guess this isn't a problem with methanol?

It wouldn't matter on a gas engine either. Cars fire every time the piston comes to the top in late model ign systems. It's called waste spark.

That makes sense. After more thought, the cylinder pressure should be close to ambient during the second spark which will effectively inhibit any ignition.

Another post suggested a price of $230 for the conversion (in Japan). I wonder what it will cost here in the US, and if/when it will actually be available? The increase in weight caused by the ignition module will be more than offset by the decrease in fuel load required. With the decreased fuel consumption this mod will pay for itself rapidly (within 15 gallons of fuel burned at todays prices...).

Also, the "waste spark" will require far less power than the ignition spark. There is likely little to be gained by firing only on the combustion stroke (vice firing both strokes).

Hi All,

Just take a look to this video : a 160 DZ converted to spark ignition ( MULLER module / Rimfire VR2L spark plug ) :

http://fr.youtube.com/watch?v=CSQkDmEtGns

Incredible idle, absolute no vibration, full power !

Best regards fro france

Oliver ROGEAU
EulBoyington

It's Greek word.....Its come from stoichio which mean amount or proportion....and its come from metria which meanmeasure. Put that together and you have stoichiometria (LOL)
So there you go!!

MattK

Bill,

Thanks for sharing this info. Just curious about the battery drain on you 6 volt airborne. Is the 19x11 available yet and from whom? 20% oil for an ignition engine seems high to me. Have you played around with oil reduction any?

The 5 oz weight "penalty" is small to get the reliability and smoothness of CDI. For similar reasons I have gone to the ZDZ40 cc. About 13 ozs difference overall in my set-up compared to a typical 4 stroke set-up (8 ozs gasoline is all that's needed). Just need to build lighter.

MattK

Matt,

What is the total weight of your airplane with ZDZ 40? I tried 3 years ago (Abbra) and was a little over 11 lb.

Vicente "Vince" Bortone

Own design I call Paradigm. Large model by today's standards at over 1100 sq inches. Projected at 10# 12 to 11# flat. A tall order but I will do it. I hate monokote so it will be painted. Some components are molded in my own molds. Of course extreme attention to weight buildup at every step. Covering is .2 oz carbon mat applied with nitrate dope and epoxy paint. Very light and strong / stiff construction. The foam is special 1/2 pound density stock....the weight savings are substantial.

The soft mount is very light, (2.4 ozs) also made by me. I have run it and does very well. 20x10 wood prop turning around 7K on a stretched pipe. Eventual prop will be 22x12 own design . Haven't decided yet what the construction will be. Maybe laminated wood to preserve sound or maybe a carbon and wood composite. Either one will be lighter than plastic

Not in any particular hurry to get the model finished tho so it will probably be done next year. I may write it up as an article if a magazine will show interest. I am collecting some photos as I go