Wico Hot Coil, Duane

Ive used the so called Hot Coils just on faith that they yield more spark gap energy, but like Duane, I have no proof or electrical evidence or even antecdotal evidence whatsoever they do. In order to measure what, if any, improved performance they offer, it would take some sophisticated electronic test equipment which the average Joe doesnt have. In addition, even if they did indeed allow for more energy to be discharged across a spark plugs gap, I seriously doubt a dyno test would show much HP increase. Furthermore, I doubt any human can ACCURATELY detect the difference to the point of proclaiming "Gee see how much better she runs with that hot coil"

THAT ALL BEING SAID lets get down to the physics (Duane) and engineering (yours truly) of how a so called hot coil might produce more spark gap energy then a regular.

OKAY if you change out the coil and alllll l else remains the same (which is basically true) the rotors magnetic strength dont change,,,,, ,,,,, ,the iron coil core dont change, you use the old one,,,,, ,,the air gap and laminations etc dont change,,,,, ,,,the RPM dont change. THESE ARE ALL (especially rotor magnetic strength and RPM) factors that influence the energy imparted into the coil by the spinning rotor.....

Sooooo ooo it looks to me like for the so called Hot Coil to produce more energy it has to be the result of things like:

1) The wire used has less resistance per unit length so theres less heat energy loss. (higher quality wire)

2) The insulation used is thinner such that the wire is denser (more wire/coils packed in closer together) and resulting magnetic flux density is increased. (higher quality thinner insulation)

3) Similar to above, the closeness and density of wire n coils between the primary and secondary is improved which also improves the mutual inductive coupling from primary to secondary resulting in less losses.

I INDEED BELIEVE SUCH WIRING AND INSULATION IMPROVEMENTS CAN RESULT IN A MORE EFFICIENT COIL..... Anyone disagree with that???

BUTTTTT TTTT to really see if the coil yields more energy to be expended across the spark plug gap (same gap as used before with old coil mind you) one would need to accurately measure the voltage x current x time of the spark. Then if the hot coil yields more energy, I guess as an engineer Id have to admit YES THEY ARE SUPERIOR

Dont get me wrong, I use them on faith they are indeed superior and plan to continue, Im just saying it would be nice to see some hard core electrical proof of such cuz im convinced no human can reallyyyyy y tell the difference and doubt a dyno would show much, if any, HP change. Furthermore, I doubt even any vendors have access to any such real data, its the stuff ONLY the designers n test engineers at the coil company may have.

NOTE I think our buddy Glen sent me some Wico literature which indicates the hot coils have greater inductance (makes sense if more wire or coil etc) and therefore if used one should also use a higher MF rated condensor (also makes engineering sense) which if I recall was the X 6916 ??? versus the standard condensor. Id have to dig out the notes when I gave my last Wico Seminar. TO MY SURPRISE when I asked some rebuilders at a show recently if they used the higher MF rated condensors when they installed hot coils, THEY NEVER HEARD OF SUCH and used the same regardless !!!!! !!!!! To me if the coil has more inductance, the condensor size should also be changed !!!!! !!!!!

Duane, absent a conflicting seminar of my own, Im gonna be in the front row and looking forward to your mag seminar at GOG next March. I was forced lol to give it the last 2 or 3 shows n wanna see if I made any mistakes????? Although Im knee deep in theory, I havent repaired them professionally like you. See ya there

Your thoughts on the above ????? ??

John T

Well, here is what I think I know (remembering it's not what I know that gets me in trouble, its what I THINK I know that gets me in trouble).

WICO developed the X series magneto and announced it in July 1946 as a big improvement over the C. Sometime later (would have to check further for a date) they announced a "heavy-duty" version of the X, which they named the XHD. The XHD magnetos had a "heavy-duty" magnetic rotor which used AlNiCo-6 magnetic material, and required a different coil and condenser to be used with it. The AlNiCo-6 material provided a higher magnetic energy density than the AlNiCo-5 used in the X, and that allowed effective use of a "larger" coil, and that required a condenser with a higher capacity value.

The coil used with the XHD is now sold as the "hot" coil for an X series magneto. WICO seemed to make a point of using the proper coil and condenser with the XHD rotor. So, I'm not convinced (from some crude measurements I made) that there is any real advantage of using the "hot" coil in an X magneto with an AlNiCo-5 rotor as it may not have sufficient magnetic energy density to utilize the XHD coil.

The XHD coil does have larger inductance and resistance values for both the primary and secondary windings than the standard X coil (yes, John, a true nerd physicist measures those quantities).

WICO never made an XHD version of the commonly used XH-477, XH-1042, and XH-1263 magnetos used on Waterloo-built Deere tractors. However, magneto suppliers do provide a magneto for tractor pullers which is a 4-cylinder XHD that has the proper impulse range, and two of the output terminals are grounded. I would believe those would be able to spark a gap which would require more energy than available from a X series magneto, but I would have to do some better measurements to decide if a X series with a XHD coil and condenser could meet the same requirement as the modified XHD.

I forget what version of AlNiCo was used in the C magnetic rotor, but it came out in 1938 (I think) so it was one of the first versions of AlNiCo (which was discovered and developed for application in the mid-late '30's) and surely had less magnetic energy density than the later -5 and -6 versions. So, it is understandable that the magnetic-rotor, coil, and condenser combination developed for the C may not provide adequate voltage output to spark a plug in a high-compression Deere engine. However, properly setting the edge gap can increase the HV output from any magneto, but that is another story.

This topic will be dealt with in my magneto talk at the March 2008 Gathering of the Green conference, and I'm looking forward to some good contributions from you, John. But right now I'm working on understanding the history and differences between the DIXIE and Splitdorf AERO magnetos used on Waterloo Boys and D's, and that is some interesting history - to me at least.... . As those of you who have attended my talks in the past have likely recognized, I like to give some historical perspective to the topics I address.

Hope this helps some - a very interesting discussion to date which I appreciate!

Oh, yes - the original drive cup spacing washers were 1" in diameter and allowed a 1-turn wind-up on the X impulse cup. A nice development for the XHD was the use of 3/4" washers, which allow a 1 1/2 turn windup on the X impulse, which allows more energy to be stored in the spring and released when the impulse trips, and since the HV output is proportional to the speed of the rotor, a hotter spark for starting is provided.

Sorry for the long post.

I think theres concensus (better be cuz its a fact) a coil is a PASSIVE device, it creates no energy but can only store and transfer it and all the energy imparted into is created by that spinning rotor magnet, while the faster it spins (fixed by tractor or impulse RPM, we cant vary it) orrrrr rrrr the greater the magnetic field strength (We CAN change that using higher rotors like you discussed) THE MORE ENERGY. THEREFORE, it dont matter if you use a stock coil or a superrrrr rrr deluxeeeee ee coil, you cant get any more energy out of it then what that spinning magnet puts in..... ..... ..... .. THATS FIXED/LIMITED REGARDLESS OF WHAT COIL ONE USES

Sooooo ooo for the so called Hot Coil to deliver more spark gap energy discharge (given the same rotor) it would have to be more efficient (wires, less resistance and better density) and have less heat losses with improved mutual inductive coupling between primary n secondary

I WOULD SAY THAT WHICH FOLLOWS IS THE SUM TOTAL OF OUR HYPOTHESIS..... ... 1) I fully understand where youre comin from, given the same rotor (thats the energy input source), the hot coil isnt getting one bit more of energy imparted into it then with the stock coil,,,,, ,,,,, ,,,,, ,,,,, ,,,,, , and where Im comin from is the only way THEREFORE it can deliver more output energy is if its a more efficient coil PERIOD

2) I think we would agree to build up a true XHD Mag one needs BOTH the higher magnetic strength rotor,,,,, ,,,,, ,PLUS the XHD coil with the correct sized condensor, cuz other then perhaps??? improved efficiency (what I say would be required), the simple addition of the XHD coil cant add much other improvement (what youre sayin)

Now whether or not its a more efficient device (less heat losses) would take some sophisticated test n measuring equipment AND I HEREBY CHARGE YOU WITH THE TASK OF DETERMING THAT BEFORE 2008 GOG

Thanks yall, great discussion, for Nerds at least lol See ya next March at GOG 2008

John T

I ain"t no electrical engineer, but I"ve been called a nerd a time or two... The following is what I think, and if you see any holes in it, please poke away.

Anyway, it seems to me that if the secondary part of the coil has more windings in proportion to the primary, that the voltage of the spark is going to be higher, and will jump further. I also think that the spark energy could be higher, and the system could draw more current with the same magnets and rotational speed, depending upon the design of the coil. It would just take a little more mechanical effort to turn the mag through one rotation. So a little bit more mechanical energy would be transformed into a hotter/higher energy spark.

It makes a lot of sense to me that you would want to couple the hotter coil with the ability to store more mechanical energy in the impulse spring, because this is the energy that will be available to you to make that hotter spark when you are trying to start the beast.

Kurt

(not a physicist)
(not an electrical engineer)
Architect and full time tinkerer

BUTTTTT TTTTT T thats NOT whats goin on here in the magneto situation where the magnetic rotor passes by and DC current flows in the primary (electromagnetic induction) and then that current flow is broken when the pointt open

and thennnnn nnn the output voltage ramps up startign at ZERO, its NOT suddenly sittin there at 10,000 volts..... And how high does it ramp up????? ????? ONLT until its high enough to arc current across the plug gap which 10,000 volts is typical BUTTTTT TTTT I dont care if the turns ratio or some super HV coil has the CAPACITY to achieve 100000 00000 000 volts, it only rises to enough to fire the plug REGARDLESS and like Duane n I been talkin, the so called HOT COIL dont fire the plugs at any higher voltage. Its just that if the rotor has more magnetic field strength it can induce more energy n current flow into the coils primary and in turn more energy (volts x amps x time) can be dischaerged across the plug gap buttttt tt still regardless of the coil or even the magnet strength its NOT gonna fire any higher (but may have more arcing current amps or arc duration if more energy) then the stock coil

AGAIN if the hot coil is more efficient it might impart more ENERGY (volts x amps x time) to the plug gap given the same magnet strength input although the firing voltage is stilllll llll the same UNLESS you widen the gap or raise the compression. It still cant create any more energy then whatever magnet strength n rotor speed determines how much energy is is on the input REGARDLESS HOW SUPER OR HOT OR HV IT MAY BE...

Your point about mechanical energy and the impulse wind n trip spring mechanism has merit. The faster the rotor spins by the coil the moreeeee eeeee energy transfer n more energy is put into the coil sooooo ooooo if you wind a spring tighter or its a stronger spring causing the rotor to spin faster when the impulse trips THE MORE ENERGY and NOTE I said energy cuz the plugs firing voltage stays the same (see the above) although the increased arcing current (i.e. HEAT) or arc duration having increased can indeed improve starting yayyyyy yyyy In that situation you input n store more mechanical energy by winding a stronger spring or winding it tighter n one would expect to get more energy out when you relases that stored up potential energy when the impulse trip to spin the rotor AND YOU INDEDD DO cuz you spin a mass at a faster speed which transfers more energy into that mag coil. You input n store more potential mechanical energy in the sprign which yields more spark gap energy (votls x amps x time) albeit still at the same plug voltage as the gap n compression pre determines

I have a tuff time un convincing folks those super HV coils fire the plug at those super HV numbers of 40 k etc THEY DONT FIRE ANY HIGHER THEN THE STOCK COIL (firing voltage is a function of the medium (fuel n compression) in which it fires PLUS the plug gap distance) buttttt tt they have the capacity to ramp up to higher necessary voltage should the plug gap be widened. Thats what you do with an elec ignition and a HV coil and use of a wider plug gap, i.e a hotter wider more current arc spark to better ignite the fuel

Enough already, we cant cover n explain here what it takes 1000 books to do grrrrr

Mt favorite daughter is a Ball State architect grad now intern at BRW in Dallas Wanna hire her lol

best wishes

You follow this????? ?????

John t

Anyway, good discussion. If your daughter has any reason why she might want to relocate to Raleigh, tell her to look me up. We"re hiring.

Kurt

THERES NO FREE LUNCH as far as energy is concerned n we cant create or destroy only change its from like potential spring mechanical to electromagnetic then to pure electrical plus the heat of the coils inefficiency.

The daughters gettin into all this sustainable n green architecture stuff which I think is a good thing n the wave of the future buttttt t as a lowly intern shes stuck doin restrooms n parking lots for post offices fer now at least.

JT

The second item is that there is some measurable power gain with seriously powerful spark discharge. A study was done (stuck in my head and not addressable) that used plasma discharge ignition with consumable electrodes that were progressively adjusted as they burnt off. There was pretty massive current and hot metal electrode particles were involved in the igniting of the mixture. Mixtures make the highest power when they burn just at the limit of flame travel without detonation in the remaining Fuel air. This allows the engines Peak Mean Effective Pressure to be in the combustion chamber at about 4 to 12 degrees after TDC. Thermal and dynamic efficiency is as good as it gets. The plasma discharge was igniting a larger "kernal" of the mixture faster (a nugget about 12mm in diameter) thus reducing the time to pressure of the burn.
There is additional research to indicate that in high speed engines of from 6 to 18 000RPM (yes those numbers)the use of higher spark energies will make 1 to 3 % more power. (time are so important).
If a mag has RPM advance capability, and good efficiency in coupling to the magnet, It will be fine for The low spaae iron we show interest in. whether they be Green or Red or Prussian orange. Jim, University Professor and Technologist.

I'm not aware of any redone magnetic rotors - it would be some work to machine the cam correctly, harden the shaft where the impulse stop plate rests, etc., etc....

Sometime I want you to lay some physics on me about ionization and arcing current inside that cylinder of compressed fuel and oxygen and how as compression rises theres greater density and more atoms sittin in the way between the plugs ground strap and electrode tip and how that all affects the voltage required to arc current across a given gap distance i.e. compression versus more voltage required to fire the plug wooooo oooo hooooo ooooo o

Maybe we ought to take this off line cuz we cant cover in a paragraph here what it takes books to fill I realize

John T

Will

It was my understanding from Glenn that the real advantage in the hot coil was in easier starting. Extra turns of wire in the coil, higher voltage and bigger spark at relatively low RPM when the impulse of the mag trips. I don"t think it would have any effect at all on horsepower. The spark is going ignite the fuel/air mixture, not add any energy to the system. The engine is after all, powering the magneto. TANSTAAFL.

Glen rebuilt my mag buttttt ttt the main reason it has such a strong start spark (you can weld with it lol) is NOT JUST THE HOT COIL its also cuz he uses a smaller diameter 7/8 bushing and gets an extra half turn of mag spring pre wind/load out of a still stronger spring WHICH CAUSES THE ROTOR TO SPIN FASTER WHEN SHE IMPULSES. The faster the rotor turns in a mag the more energy it produces wooooo o hooooo oo a faster impulse spin means more spark gap energy discharge n easier starts

I love tricity

John T

• John T's Mag

I agree with what your mag man said in that I as an enginner also doubt the HP would increase significantly if you simply add a hot coil. So long as the mag fires the plugs at a decent energy, I just dont see significant HP increases caused solely by use of a hot coil. Thats NOT the same situation as if you raise the compression and then use a high energy mag as required to fire the plugs at all, the necessary high energy mag and a souped up engine will sure make more HP.

Hope this helps, what Im lookin for is some hard core electrical specs n data which shows the energy improvements the hot coil can provide, not whether or not it has the capacity to fire at higher voltages should they be required....

Good discussion, thanks

John T

John T (Also a Geek and Nerd Wannabee, but I dont have the black horn rimemd glasses with masking tape in the middle and a plastic pencil pocket saver)

Like I explained to my kids years ago when they asked about solar heating a home ALL HOME HEATING IS SOLAR HEATING Coal or oil or natural gas or wood or whatever was alllll l made cuz the suns energy made plants grow long ago and we are now usign that energy thats been stored all these years, they were impressed I think lol

JT

Fer sure if a coil has less resistive wire,,,,, ,,,increased wire/current n increased flux density from tighter windings and/or thinner insulation,,, ITS MORE EFFICIENT WITH LESS HEAT LOSSES,,,,,HAS IMPROVED MUTUAL INDUCTIVE COUPLING,,,,, ,AND CAN DISCHARGE MORE ENERGY ACROSS THE PLUG GAP given the same input energy of the rotor spinning past it

Those are the benefits it has to offer:::::

I will take any improvements it has in a Magneto Ignition, Id just like to see some side by side engineering data comparisons but I doubt we find them here or if Duane has any....

John T

• John T's B

John T