just a question

[kendelrk]

so this has been buzzing around in my head, an engine is an open circut until ground out to shut it off, so if you had a spark plug wire without the boot that just sits on the spark plug, can you take a standard peice of metal, put it into a positive battery clamp from say a car jump box, and touch it to the spark plug, would this work as an electric start? i figure it would because theres gas in the carb, it ignites moving the crankshaft which turns the flywheel, creating the spark continually and keeping the engine running, what do you guys think?

 

[dave1701]

You are missing a starter motor. I'm pretty sure the engine needs to be turned over.

 

[kendelrk]

i thought the combustion would turn the flywheel and continue the cycle

 

[r_chez_08]

Wont work. No fuel/air mixture in the cylinder until the engine is turned over "pulling" the mixture in.

 

[r97]

it could possibly work, but nearly as smooth as you seem to think it would. you would need a few thinngs to happen:

1. create an ample spark to ignite the gas, then switch to the coil right away.

2. get enough power from that one combustion to spin the engine around from a dead stop enough to get more fuel from the carb, generate an ample spark from the coil, and make it all the way to, and they through the compression stroke.

3. have some way of pouring gas directly into the cylinder and then getting the piston in the perfect spot, and hoping the fuel just magically ignites the first time (unlikely)

there are probably a few other things too that i'm not thinking of right now. in theory it could work, but i am highly doubtful it would be at all practical, or work at all.

 

[kendelrk]

i thought you would just touch it to the spark plug, ignites the gas, lets the exaughst out and as it does it pulls in because the piston moved, so then it turned the crankshaft from combustion, which turned the flywheel which created spark, i figured you would just touch it to the top and pull it away

 

[bighead]

Will not work. Even in a million tries.

 

[r_chez_08]

1: you need the cylinder at top dead centre
2: you need gas in the cylinder.
3: it probably would not have enough power to keep going.
Edit: i just pretty much summed up what r97 said

 

[devino246]

Car batteries are 12 volt, spark plugs need somewhere in the range of 4,000-10,000 volts. Besides that, you need to get the engine turning in order for it to: A) eject the air thats been sitting in the combustion chamber since you last turned it off, B) Suck in fresh fuel/air mixture, and C) generate a spark to ignite the mixture.

Additionally, the engine needs the momentum of the flywheel to get from one compression stroke to another. If you did somehow manage to ignite the mixture, id bet it would just bounce off the next compression stroke and quit running.

 

[bighead]

Not to mention maybe frying all the elctronics.

 

[HellSpawn]

You guys forgot the main reason the motor needs to be turning to start, Raw fuel will not ignite very easily from a spark. It NEEDS to be compressed.

 

[Doc Sprocket]

And another point- The engine is NOT "an open circuit" until grounded, or otherwise. The magneto system is a closed, complete circuit. When you apply a ground to the kill lead, you are not completing a circuit, you are shorting (bypassing a portion of,) an already complete circuit. Problem is, from OUTSIDE the engine, you don't see the rest...

 

[kendelrk]

oh i see, its just a thought, i knew it probablly wouldnt work and that i probably hade my thoughts wrong, but thanks for clearing it up

 

[Russ2251]

Back in the model "T" Ford days, engines could be started by just futzing with the manual spark advance which was located on the steering column.
This method was unreliable at best, and you had to be extremely lucky for it to work.
Unlikely that it would ever work on a cold engine.

 

[wall gator]

Back in the model "T" Ford days, engines could be started by just futzing with the manual spark advance which was located on the steering column.
This method was unreliable at best, and you had to be extremely lucky for it to work.
Unlikely that it would ever work on a cold engine.

Just in case,that did'nt work.....you had a hand crank!!!!

 

[Russ2251]

Just in case,that did'nt work.....you had a hand crank!!!!

I have experienced them. A '59 Renault Dauphine came with a hand crank as did the early V-dubs.

 

[CaptCanadia]

Aw man that must have been horrible. Image getting up in the morning in the freezing cold and trying to start that thing. Not only that im sure a million other things always went wrong. I'd just stay with my horse thank you.

 

[anderkart]

You guys ever see how some older airplane engines could be started using shotgun shell cartridges?

Checkout this video:

(ps: this is an awesome movie that anyone into building DIY projects should see)

http://www.youtube.com/watch?v=IACjOvyx5hs&feature=related

 

[Bluethunder3320]

i think some old tractors were started with shot gun shells.

 

[Bluethunder3320]

http://www.youtube.com/watch?v=VEurohAwrmA&feature=related