I liked my forst Poulan 25cc conversion so much, that now I'm thinking about another one but this time using electronic ignition. The engine alone (with carb and prop hub but without flywheel and magneto) can weight no more than 2 lb. So it is nice candidates for light gas egnine.

So the question is: What type of electronic ignition can I have? The engine costs 25 bucks so I want that ignition cheap too

I know everything about CH but this thing can run over 170 bucks (with pickup and variable timing).
Ignition from VLACH looks better (two magnets type) for a little over $120.

What elese will be cheap, light and reliable but will not look like 'agriculture style'.

I read here and there about RCIGN work, but I can't find any specs on that? How does it look like? What is the weight? How much does it cost?

RysiuM

Most of the guys will tell you not to bother with variable timing, they say the small engines dont benefit much. I have a Homelite 30cc with set timing CH ing and it starts by hand so easily (from new) that its just not worth it, if you can make your own hub it will make it cheaper, cost me $100 to convert to electronic ign in the end.

There is only one benefit from using variable timing an these engines: They idle lower - with fixed timing set for the best power the idle will be a little higher than with the variable timing ignition. Such small ongine will not kick back so starting by hand is not an issue. So you are right.

Going for electronic ignition is for me the weight saving option, not the performance. I figured out, that I might save at least 8 oz using electronic ignition instead of flywheeel. Making my own hub is not an issue - I can mak it for one or two magnets any size. The weight and the price is the main factor.

RysiuM

here is some info on cheap ignitions, these are not cd ignitions! but they have worked.


http://www.jerry-howell.com/IgnitionModules.html

http://www.5bears.com/tim4.htm

You might wont to take a good look around the 5bears site there is some excellent stuff there.

Don,t wast time...best ignition for the buck is sold by RCIGN1 Check it out. Good luck Capt,n

I need good luck, as I looked around and except good words I didn't see anything about this ignition. Website is dead, RCU has just "oh my God, how good is that", and I don't want to bother man calling him just to see what he has. Do you have some more info about that? maybe something like: size, weight, source of power, installation example, price maybe...

RysiuM

Take a look at the thread on 'Scratch Built Ignition??' http://www.rcuniverse.com/forum/m_74..._1/key_/tm.htm
A lot of great info there and several sources for complete ignitions and parts. I hope to do some testing this weekend with CD ignitions bought from marlowe and rsholl - under $100 each. Great service from both of those guys. Most all of the sources listed have glowing comments about their service, too.

Marlowe has a really good explanation of CDI on his site http://home.earthlink.net/~marlowedc/CDI.htm

Cheers
Bill

I think I found the best ignition for my Poulan 25cc. Glow plug. Engien fires and runs smooth on regular gasoline/oil mixture so the glow needs to be powered all the time. I also check the option of using gasoline-methanol mixture maybe to save on on-board battery, and it runs fine, but with glow powered all the time it runs better. Even it starts by hand The performance is a little better (50 rpm more with glow than with magneto). Running on gasoline-methanol mixture (50%-50%) increased performance by additional 300 rpm.

So this is the best weight saving option:
- glow plug (with adapter) weights only 1/2 oz, regular spark plug is 1 oz.
- on board battery needs to deliver only 1.2V (not 4.8 for ignition). It needs to give four times higher current tho, so the battery weight gor glow is the same as for ignition for the same flying time.
- No ignition module needed so this is the saving 2 - 5 oz (depends on the ignition brand).

And the best factor: cost I turned my own glow adapter, but you can buy one for 10 dollars or so. I didn't see ignition available for $10 or less.

My goal is to have this engine 2-1/2 lb or less ready to fly: Engine with prop hub, muffler, mount and on board battery. I couldn't make it with ignition. (it is about 17oz more with magneto).

RysiuM

don't forget the increased fuel weight when running the gas-methanol mix.... as you noted, the carb has to be set up richer and the oz./min will go up....

but I'm with you anyway.... the increased fuel consumption is worth it....

[:-]

The fuel consumption increase on the 50%gasoline/50%methanol shouldn't be more than 10-15%, I was still getting 20-25 min of flight time with my FeatherLight 25 on 16 OZ of fuel, maybe we need to make a test to determine the duration of straight gasoline vs the gas/methanol mixture and get real numbers side by side, but like I said by real flight experience I didn't feel any loss on flight duration (relatively speaking), so you can keep your same size fuel tank without having to increase the size of it to make up for the consumption. what oil ratio are you using?

Poulan says to use 1:40 (it is a weed whacker, so any Home Depot or Wall Mart stuff will do), but for gasoline test I used 1:30 Motul (synthetic). For metanol-gas test I used Castrol Racing 1:40.

I don't want to kill my Wilga engine (the one with magneto setup), so I will continue testing when I finish my second engine - the one that I prepared just for glow.

RysiuM

What brand of gas and what octane are you using in the mix. Will any pump gas in Michigan work? Or do you need EP 85? Thanks Capt,n

Hi captain, I am using Arco's 87 octane and methanol I don't know if the composition of gas up in michigan woul be the same as here in california I guess is not, but try just your regular 87 octane gas ans see how it works with you just make sure to use an oil that will mix with both gasoline and methanol (Klotz works very good or try as I do 50/50 amsoil other good synthetic and castor oil) and if you can get ahold of sime nitromethane try it at 5%

What is that animal 'Castrol Racing Oil'? How is it related to other good synthetic oils (like Amsoil)? Do I need it more, same, less or should I mix it with some synthetic oil for running? I like my engines to run no less than 1:40 on synthetic oils.

RysiuM

AERO NUT I have some new Omega 10% glow fuel. If I mixed some with gas.....would that work? It has the lube in it to start with. How do I figure out the best ratio to mix the gas and the Omega glow fuel together??? I think making it easy, will get more of us trying this new idea!!! Thanks Capt,n

The problem with premix glow fuel is that it already contains a lot of oil. Omega has 17% oil. Even if you mix it 1:1 with gasoline, you will have over 7% of oil - it is like 1:15 oil:gas mix.

RysiuM

OK...now how about 1 gal of Omega + 1 gal of Menthanol Alky and 2 gal of gas. What ratios do I have then? Thanks Capt,n