Cyclic Hardover

My Feedback: (3)

Would you mind telling me if first, it was worth the money. How well does the engine run is my mine question. Already know how well the fuel consumption is and other things but mainly if you were satisfied with it.

NM2K

My Feedback: (14)

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I have done a considerable amount of research into converting glow engines to burn gas/oil mix with a spark ignition.

The main problem, at least for me, was that the lack of needle bearings in the appropriate places meant that you were going to have to use a LOT of two-stroke oil in the fuel mix. Much, much more than an engine that was designed to burn gasoline originally.

Also, while our glow carbs are fine for glow fuel, gasoline engines need carburetors that meter the fuel mix in much finer ratios than glow carbs are capable of providing. If the glow engine is large enough to accommodate a Walbro or Zama type of carburetor, then that problem is solved. A while back, someone was selling adapters to mount Walbro carbs on a TT 1.20 glow engine. All you had to do then was to run a pressure line from the pump side of the carb to a backplate, or other location, mounted pressure nipple. But you still had to contend with burning a very oil rich, smoky and plug fouling fuel mix.

For me, I decided that it would be better to just buy an engine that was manufactured/designed to burn gasoline/oil as its original fuel. Believe me when I say that we have many more engines available today in the smaller sizes (.90 on up) that are set up to burn gas/oil fuel. The BME Super Tigre G90 is one such example. Yes, it is expensive. But the engine is equipped with the necessary new crankshaft (hardened appropriately) and the requisite needle bearings and pumper gasoline carb. It will run satisfactorily on 50:1 gas/oil mix, like other utility two-stroke gas/petrol engines.


Ed Cregger

Cyclic Hardover

My Feedback: (3)

I'm considering the 3250, had one several years back

TLH101

My Feedback: (90)

Some info here on the FAQ, on C&H's web site: http://www.ch-ignitions.com/#faq

chevy43

You can buy the whole ignition system from Floyd Carter and it is 3.1 oz with battery - way lighter than the C&H system. $68 for the system and you mount the Hall effect pick up and magnet. I have his # but I don't know that he wants it on the web so PM if you want it. You will loose some power but idle is really nice suposedly.

None of the old time engines had rollers on the rod either ( correct me if I'm wrong )

Cyclic Hardover

My Feedback: (3)

Well that was depressing. Those CH guys do not recommend changing over on the larger glows since the end cost can be as much as a new gas. Maybe so but I wonder if you come out with a better engine. I need to consider the weight, overall size and power.

G26 is about as large in size and weight as i can go but the 3250 is a heck of alot more powerful and close in weight. can it be a coin toss here?

Charley

My Feedback: (2)

Taken in order on a Saito 1.5 on gas:

Was it worth the money? That's an intangebal (sp?). At the time I did it, I was exploring the possibilities.

How well did the engine run? Quite well, in my experience.

You didn't ask, but it used less gas than alky.

Was I satisfied with it? Yes.

I got into this experiment becuse I had one of the early Saito 1.50s that backed up and pitched props. One of the things that was recommended was to put an ignition on it. So I got one from CH Ignition, along with a shim that went under the jug for lowering the compression ratio. The engine ran beautifully with that setup! No more deadsticks! You wouldn't believe the sound of the slow idle.
So I thought, "Huh, I wonder how it would be on gas." I was a little worried that it would overheat but I thought that since it was mostly exposed in my 4-120 bipe it would have its best chance to stay cool.

I ran a 16-to-1, gas-to-oil mix and tried it. I replumbed the tank, etc., and cranked it up. It ran well, using the original carb, leaned out a turn or so. I think one reason this was possible is that the Saito HS needle is very fine thread and needle taper. So is the old Saturno
ST carb, BTW. I flew that setup all during that summer with no problem. I put it back to FAI fuel without the jug shim just to see how it would work after all that breakin. Then went back to glow to see how that would be. Flying it now on 10% nitro, 2-stroke glow fuel.
I plan to put the ignition back on so that I can run it on FAI fuel. Fuel costs, y'see?

So, that's my experience. All I can say is that this worked for me. YMMV.

CR

Edited for gas-oil ratio - working from memory.

Charley

My Feedback: (2)

Some of the contemporary gassers have sleeve-bearing rods. A friend of mine has a RCS 1.40 that has a bushing rod. Dunno what the latest ones have.

CR

chevy43

You also need a Rim Fire V-2 plug for about $18. It goes in place of the glow plug and has the same thread. I haven't done this yet.... I sure would like to hear how it comes out....

All this stuff is old school from the '30s and '40s except now the points are replace by Hall efect and the ignition unit is electronic otherwise it all has been done way back in the day....... It should work fine exept for maybe the carb issues.

Charley

My Feedback: (2)

Do the plugs cost that much now? I haven't had to buy one lately. CH or RC IGNI have them. When I bought my last CDI, the plug came with the ignition. In my experience they last forever, unless you foul them out with improper adjustments.

CR

chevy43

Are you thinking of the bigger plugs by chance? - those are cheap... Volume = cheap. I bet there arent very many 1/4 x 32 spark plugs made each year.......

Here is the link to the sparkplugs

[link=http://sparkplugs.morrisonandmarvin.com/index.cfm?menu=order]Rimefire plugs[/link]

Charley

My Feedback: (2)

No, I just didn;t know they had gone up so much. Last one I bought cost ~$12.

CR

shakeelsid

I wasnt around model aviation in and around 70s but it is my understanding that a some Enya 60s and Fox eagles were converted to gas. If I remember there were people selling ignition kits for these engines. I have disposed off all my older MAN issues so I have no way of cofirming, but I do recall Peter Chinn running a series of tests on these small gas conversions
care to comment anybody?

Hobbsy

My Feedback: (102)

Charley, I converted this OPS 30 Maxi to gas, it ran fine but was about 500 rpm weaker than glow. I used a CH ignition with SynchroSpark set to 28 degrees all up. This engine has needle bearings on both ends of the rod and could run with much less oil than I used, I may try it again some day with less oil. It is along stroke engine designed for 20 inch props so is not bad on fuel. The Dellorto carb is a great carb.

NM2K

My Feedback: (14)

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And all of the old time engines ran very, very high oil content fuel too. Plus no one expected them to be throttleable. Right? <G>

I'm not saying that no one should experiment with converting a glow engine to gas/oil fuel mix. I'm just saying that you shouldn't expect to run the same oil to fuel ratio as normal utility gasoline fueled two-strokes, that's all.

Oh, and for those that prefer C&H ignition systems, Brillelli is selling the fixed timing version for $90 plus shipping. And the synchro spark module is going for $30. Yes, I do experiment with engines. I just don't brag about it. It's easy to do and I don't have to go anywhere to do it - running the engines in my home's driveway.


Ed Cregger

Cyclic Hardover

My Feedback: (3)

Ed, what do you think about my statement here? Would I come out with a better engine by converting a 3250. I assume it would also elimintate all the midrange aggravation also.

Charley

My Feedback: (2)

That's a beauty! Did the Dellorto carb come with it or was that something you added? What model did you fly it in?

I don't remember the RPM figures, gas vs glow fuel, on my Saito. I do remember that there was less power on gas. I can't seem to remember what the ignition timing was either. I hope I still have the paperwork from CH. []

CR

chevy43

The problem with the C&H that I remember is that it is alot heavier. This other system is suposed to come in at 3.1 oz with the switch and the 700 ma battery - the whole system!

Ed's right. You need alot more oil with a plane bearing engine. How much is the question. 18% oil should be enough? I don't know how long plugs will last with that much oil on them.......

chevy43

I was told that if you don't want to bother with carb issues that this conversion works really well on glow fuel........ I'm not sure what you gain exept an amazing idle.........

NM2K

My Feedback: (14)

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If you don't already have the ST 3250 (which I like as a glow engine), I would go with an SPE 26/40cc engine or a Zenoah G26.

While the ST 3250 makes a lot of power on glow fuel, it will not be nearly as powerful burning gas/oil. It's not the engine's fault, it is just the nature of gas/oil.

As far as I'm concerned, needle bearings are a must have in a gas/oil engine. I am aware that the RCS 1.40 has a bushing upper end on the connecting rod, but I thought that the lower end had needle bearings. I've been wrong before.

Of course, none of this takes into consideration the enjoyment factor of making something run differently than it was intended to run. If that is part of the goal, then you probably couldn't find a better bushed connecting rod engine to experiment with. Or, you could cheat like Hobbsy (<G>) and buy a glow engine with needle bearings already in place.

I'm a big believer in what works - works. I'm surprised that Charley had such great success with the Saito 1.50 on spark/gasoline. Those engines don't even have a bushed connecting rod, so I'm really surprised. Way to go, Charley.


Ed Cregger

Charley

My Feedback: (2)

I have a tuff time believing that weight figure. What kind of battery is that?

Ed's wrong. You can run less oil with gas because gas is inherently oily to begin with.

CR

Jezmo

I hate to bring this old thread back up but something caught my eye and I wanted to add to it in case anyone searched and pulled it up. The system supposedly weighing in at 3.1 oz with battery is not including the ignition coil. The coil is almost that heavy by itself at 2.56 oz. There isn't any way to lighten up the ignition coil by any significant amount because the weight of the copper wire and steel core is most of the weight. I also strongly question the total weight of the system due to the weight of just a battery by itself.

Actual measured weight of my components are:
2.56 oz........... = coil
2.1 oz............. = CDI module
3.98 oz........... = standard 4.8 volt receiver pack

Charley

My Feedback: (2)

What? The CD Ignitions I have (several) contain their own ignition coil. What's your setup?

CR

Jezmo

I have both. Coil internal and Coil external. The one I measured is with seperate components so I could tell what each weighed. The CH CDI box I measured is used on a Zenoah and uses the stock Zenoah secondary coil. I also ordered, at the same time, a coil to use with my Saito and I have just been swapping the box back and forth. It takes a certain amount of copper wire wrapped around an iron core to make the coil so there isn't much wiggle room there. The CDI box is Bill's top of the line CH unit and I just used a standard AA 4.8 volt pack. I kinda didn't think the numbers sounded good to me on his post. Heck I could take my AAA 4.8 volt pack out and weigh it but the total weight is still going to be too high for his post's total. The dang batteries are going to weigh that much even if I use the AAA's. The laws of physics aren't adding up here. You can't just use a real tiny battery because the discharge rate would kill it before you got a flight in. The coil has to be a minimum weight to get the spark done and at 2.1 oz's Bill's CDI is darn light. Just can't see it happening at 3.1 oz total with battery.