Volts to plug

Does it vary much in a 12v or 6v systems.

Is using a large marine type external condenser worth while? Hot rodders used them in the 50's.

Are "split fire" or other simular plugs any good?I know that extended tip plugs help in my Farmalls and JD combine. How much can you open the plug gaps on IHC 4cyl engines? Nobody seemed to want to commit to a number.

Our H has a lot of work to do this spring and needs all the power she can put out!!

My best guess (BUT it depends on plug gap and compression etc) would be in the 5,000 to 15,000 volt range.

Generally speaking (depends on the Mag and RPM etc etc) a Mag doesnt store nor can expend as much energy across a plug as a battery powered ignition, which is why good wire core plug wires and components is essential in a Mag.

Best wishes n God Bles yall

John T

Plug voltage varies from 5000-25000 volts based on demand, not supply. Thus there is no substantive difference between different primary voltages (6-8-12). Capacitive Discharge Ignition can be an exception, in that it generates spark in a totally different scheme. Not too many CDI systems are used in Farmalls. These CDI systems are not electronic ignition as we know them.

Opening up the plug gap, to assist the ignition of fuel is good today (especially because fuel has far less deposit forming additives). The voltages are higher as a result, but unless the secondary (high Voltage) parts break down, starting and operation will improve.

I hope this helps, JimN

Thereforeeeee eee I say that, as theres no free emergy and we cant create or destroy it, simply change its form, if you do things like widen the plug gap (which increases the voltage required to arc current across its gap) there MUST BE A TRADE OFF and balance, like less current or less arc duration time. I agree widening the gap (to some limited increase) can imporove performance, but I dont see it as a miracle cure by any means, nor do I get the impression you would either. IM JUST SAYING that if you change the gap, either the curent or arc time duration MUST CHANGE.

Sooooo ooo I guess the engineerign question is to figure out what combinations of voltage and current and arc time duration provides the best combustion initiation????? ????? If you figure its heat, then a wider plug gap at lower current may not be as effective as a shorter gap and more current (or time). However, if you figure a wider plug gap yields more arcing current "surface area" (even at lower temperatures) and you think thats a better combustion initiator, then the wider gap may be better to initiate combustion.

I consider an arc of current as a sudden release and conversion of electrical energy in the form of heat and light. If a blue spark is of higher temperature then a yellow spark, I see how n why the blue spark is the goal we try to achieve.

Im getting lost here lol I have a Lions Club Meeting soon so gotta run, you got any thoughts on the above Jim????? ????? or Bob or anyone else???

Take care yall, John T, just an old sparky

The dwell on a low rev 4cyl. will allow coil saturation (given)

The points break and begin the collapse of the magnetism in the coil.

The gap in the plug+ other resistance in the leads cap and rotor make the apparent resistance of the secondary infinite. The magnetism is held back by the increase in reluctance of the "open" windings. Concentrating its effect till the voltage of the gap/s is overcome. the voltage thin ionizes the fuel air in the spark gap and a lower voltage multi spark "duration" jumps the electrodes. (in the primary of the coil, this is all one way into into the condenser. Then the condenser discharges back into the coil (but with not enough intensity to spark), just so that the potential is "worn off" to limit point arcing.
(I've studied ignition traces a long time in theory and application)
A wider gap increases the open circuit voltage. The "lightening" strike across the plug electrodes is from higher voltage and thus drives increased amperage across the gap, (hotter) the duration is about the same because the condenser only acts as a reflector after the spark stops.

Modern plugs in modern engines can have .060+ gaps for this reason, they have better exposure of plasma to unburnt fuel/air.

After the initial setting of the fire the plug could be considered irrelevant, the flame front can never burn that exhaust again.

No free lunch just a more intense use of the lunch that is there.

Just my thinking/experience.
JimN

"BUT the longer the dwell the shorter the fireing time.

okay guys here is the deal I have worked on cars all my life. started in automotive when the last sun machine used in school after i graduated they threw it out. but if any body finds one at a shop sale "GET IT" for this work they are perfect.
anyways sorry got off on a tangent yes the longer the dwell the hotter the spark.
but shorter the burn.
how much voltage out of a coil?
most oil canister coils can only put out 15 kv or 15,000 volt max but for our purpose around 4500 to maby 6000.
okay youi might ask what is the proper dwell for a farmall with a prostolite distibutor?
I could not tell you. what I can tell you is to set the point air gap at the proper thousandth and get a hand held dwell tach meter. and check it and if can get acsess to a sun machine play with the dwell or point gap to get the max output. the sun machine or oscilloscope can measure both dwell and voltage.

next mags simple faster hotter they get.
mags are used in top fuel dragsters engine run in ecsess of 9000 rpms and they have big mags sometimes 2.

they are crude and not fun to play with I don't much care for them. I take them to guys that like them I do not.
moving on

the last thing to remember is the igntion systems on the farmalls are verey limited due to copper conductor wires and limted types of plugs a typical copper spark plug wire can only handle roughly round 8500 9500 volts before it melts or seaks a new source to ground. most vehicles now days have carbon spark plug wires the igntion coils have the capablity of producing 300 kv. thats not a type o.
but you are talking about electroinc igntion and no distributor igntion etc etc etc.
don't worry about that

soooo in my ramblings on you want hp?
from a H huh?
not going to get a lot from just the igntion. Just do this.
set the points gap accordingly.
put on good cooper wires custom make them short as possiable "dont zip tie them together" inductive voltage can cause a cross fire use a libral amont of die eletric grease on the spark plug contact to the wire and on the dis cap. set the dwell. maybe some one here can tell you the ideal dewll setting on this fourm and adjust the carb clean it out and re kit it if needed I know my super H needs it bad.

If youre trying to fire 8 cylinders from a single set of points with a single distributor cam and running at 8000 RPM, you then need to worry that the points were indeed closed for a sufficient time to store the max amount possible energy in the coil, but with 4 cylinders at 2500 RPM its not usually a problem. All this, of course, still assumes the air gap of the points (determines dwell time) is sufficient so proper switching action can occur absent any arcing over etc. I remember the old dual point Mallory Distributors which were developed to reduce point float and take care of the minimum dwell time problem discussed above. Of course, the use of an electronic current switch has made this old point technology a thign of the past except for us guys who love the old iron.

Take care yall n God Bless Funnnnn Discussion

John T