Spark Ignition Nitro Engine

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Ian Inverarity

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Setting aside just what may or may not be allowed by various class racing rules, has anyone tried spark ignition instead of glow plug ignition with a high nitro fuel mix?

1/4-32 spark plugs are available (such as NGK ME8). I have been using Power-Spark electronic (programmable) ignition systems on gas boats for a few years. This system can work up to 30000rpm, and has a programmable ignition timing curve and ignition energy.

Would conventional spark plugs survive? Is the ignition energy required going to be beyond normal ignition systems for gas type engines?
 
I have talked with some one that has used a lipstick stun gun as the power for just this set up on a CMB80.

It passed the bench test will see if it will run under power.
 
Now we are talking
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I think if a plug got wiped out the head would be junk too.

A long time ago we discussed what it would take to sort out AA/Fuel RC Model Boat Engines with spark and fuel injection.. The fun only begins with getting the timing curve and fuel curves figured out. Sounds like the ignition will not be a problem now what to do about mapping fuel. Then once the power starts working we will need parts, LOTs of parts LOL... First Pistons, Rods and Cranks, then cases etc etc.. All in the name of fun.... I would love to hear a two cylinder inline on fuel
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Now we are talking
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I think if a plug got wiped out the head would be junk too.

A long time ago we discussed what it would take to sort out AA/Fuel RC Model Boat Engines with spark and fuel injection.. The fun only begins with getting the timing curve and fuel curves figured out. Sounds like the ignition will not be a problem now what to do about mapping fuel. Then once the power starts working we will need parts, LOTs of parts LOL... First Pistons, Rods and Cranks, then cases etc etc.. All in the name of fun.... I would love to hear a two cylinder inline on fuel
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Norm, so you think the fuel system would need to be changed? I am talking about a system to use 1/4"-32 spark plugs in a nitro engine here rather than converting a gas motor to nitro, I would have thought the current carbs and pressure system would still be okay?
 
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The plugs would work, the programmable spark is perfect. The carbs need fuel proof rubber parts. It takes a significant amount of nitro to maintain a perfect mixture. The higher the nitro the more fuel you have to pass through the engine.

I have no clue on how much fuel one of the current gas carbs can pass on a piston ported engine. I would say get the rubber issue with the carb fixed, (easy). Then start running. If the ignition is programmable that can be used as a control to until the fuel is mapped out right.

Also if the thing goes lean it will eat parts too. David was talking about starting out with 10 percent nitro. That is a good idea then start raising the fuel as needed:) Again,. for all I know there probably are a bunch of people out there ahead of me on this. A lot of smart people running gassers.

Come to think of it, reading between the lines here..... I bet Andy Brown has most of this stuff sorted out. :0 And David is right there or at least has been burning up his mind thinking of how to do it. . Something is cooking .....
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That would be perfect. The two things that steered me away from that is the cost of engines and parts. I would LOVE to have an ignition on an engine designed for nitro like a CMB, Nova Rossi etc etc. . Now, what to use as a reliable crank trigger that is small enough to work and durable enough to deal with dirt, nitro, oil and water? I write this assuming that the ignition will need to know where the piston is in the cycle to time it.
 
Norm, the Power-spark system uses a small magnet in the flywheel and a hall effect sensor, the sensor can be seen about two thirds down on this page:

http://www.power-spark.de/motoradaption_en.htm

The only issue I have had with these sensors is when the flywheel came loose on a Quickdraw and hit the sensor. Otherwise no issues with water, vibration, oil etc. I dont know about nitro. The Power-spark systems have been very reliable for me, so I would have no hesitation in trying one in this circumstance.

http://www.power-spark.de/index_en.html
 
CARB is no problem! Just use what we have always used on "nitro" engines.

Just get a $375 Tiger King and bolt a Nitro carb on it. That's what we did. Ours is already in the boat and ready to go!

No need to complicate it. Yes, there are better ignitions systems, but certainly the "cheap" systems will burn some methanol or low nitro. Ya gotta start some place!
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I have a Tiger King to look at, certainly a cheaper engine with cheaper parts to convert to nitro compared to the CMB27.

But as I said, I am not starting from the point of converting a gas engine to nitro. I am talking about converting a nitro engine to spark rather than glow ignition. Will a convention gas style ignition system light a 50% nitro mix? Will the plugs survive?

I have no doubt a simple nitro conversion with low nitro to a cheap engine like the TK will provide good value for money performance tho.
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The CMB Gas engine looks to me like a Nitro engine converted to Gas. The would not be a bad candidate. Sort of pricey
Norm, I have been running a CMB27, its design is like a CMB RS engine, in some ways better. But they are not cheap, and I expect parts are not cheap! So I would be more inclined to use a Tiger King to sort out things like compression ratios, pipe lengths, stinger sizes, carbs, radio needles, spark plugs and ignition systems before moving to the expensive CMB!
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There you go the tiger on nitro. Cheep and easy to work on.

Andy how much have you run in it so far?

Dose it real need that much to make good power?
 
As some of you may know, my racing partners and friends, Ron & Gene Logghe (Logghe Brothers) were the first to run straight nitro in drag racing back in the mid 60's. They had a 55 gal. drum of small block chevy pistons to show for the earlier efforts but by the summer of 66 they went to California with the "Giant Killer" and beat all the guys who had switched to big block hemi's. (read that as Garlits, Greer Black & Prudomne etc.) In later years we tried to run nitro in go kart engines (Komets, B Bombs),and snowmobile engines, we weren't successful at all. These were all point/magneto or battery ignition engines and we were able to build adapter plates to get the 50 degrees to 60 degrees we felt was required to fire the nitro. The engines had compression ratios high to burn methanol. We changed out standard issue carbs for Del Orto's that had larger fuel passages. We could run very low percentages of nitro but the trade off in dependability wasn't worth the effort. Now with a programmable ignition using a nitro engine/carb that had run on glow - sounds like great place to start. Great thread guys!

John
 
Hi Duke,

I did a research project in undergrad school on "supercharging 2 cycle engines" boy was that a hoot!!! Got free engines from many manufactures plus lots of parts and blew up so many I lost count. The short story results was to just add another cylinder and forget the supercharger. I believe this was the major cause of my hearing loss.

Thanks, John
 
I did this on a rex 21 years ago, I drag race cars and bought a c&h setup. it had the hall effect crank trigger and had a 30,000 + rev max. The problem I had was it would blow the plug seals out and the guts would wiggle around, never dropped out would just pop and shut off. tried lowering comp. changing timing it would run good completive numbers but not a great step foreword. and the plugs were 7.50 when I could get McCoys for .50. I should mention my system was meant to use a mechanical advance, the pickup plate would rotate by a bellcrank to the throttle servo. The system was made for very large glow engines converted to gasoline. I had to make my own c clamp type mount that would clamp on the case around the front bearing . Me and some buddies had fun on the prop dyno seeing the difference from glow to spark numbers at idle and reving and found different top rpm's with different nitro percentages. the main problem with my setup was fixed timing and the plugs fragility with todays cpu controlled units I would love to try again. I should also add that after 25,000 RPMS you could shut it off and it would keep screaming. So it the thing would still diesel beyond, Also the carb is not a problem. Please do experiment with this I will watch with allot of interest I would love to spend on this and stop buying 7.00 turbo plugs. Best wishes jeff if I can answer any questions please flatter me.
 
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This could be a whole new world for RC boating.

But where are you going to run it?

Nether NAMBA or IMPBA have a class that will allow you to race it.

This is a definite possibility to happen very affordable.

But I my self do not have the time or extra cash to build a self queen.

The rules need to be adjusted soon for this to be a reality.
 
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