Pertronix Ignitor

I want to change my 65 4020 gas from points to the Pertronix Ignitor. What wires do I need to use? 8MM or 7MM and what spark plug should I use? Something other than the original plugs with the point ignition? Will the timing still need to stay @ 20 degree our will I be able to adjust it somewhat for better performance. I know all of this has been covered in the past, but I can't seem to find the answers to all. Thanks for any and all help anyone can provide!

Mark

Mark - I installed Pertronix system on friend's 3020 to a couple years ago. It works well and we learned this in the process:

Presuming your existing wires are OK (no insulation cracks, etc) they'll work fine with the Pertronix. But if they wires are marginal replace them with new OEM-style copper core wires. Also if the distributor cap is cracked, is crazed on the outside or has carbon tracks inside, etc. replace it too.

If the plugs have been working OK stay with what you've been using. The Pertonix will have no effect on spark plug heat range, etc. You may however open the plug gap to .045 or more to take advantage of the extra spark voltage.

You may find a greater tendency toward misfiring with dirty, partially fouled plugs with the Pertonix. If that's the case close the gap back down to .030 - .035 and go up a heat range or two. Or better yet correct the source plug fouling if the engine's running rich/burning oil.

Ignition timing should not be changed. All the Pertronix is does is provide a higher voltage spark that does not deteriorate and change timing as the breaker points wear.

Bob,Thanks for all the info. I going to try and get it installed this weekend. Did you use their coil (flame thrower) or stay with a normal 12 volt one?

Read the directions carefully that come with the Pertronics unit. They are sensitive to the ohms of the coil, a coil with low ohms causes a high switching current that can damage the module. If you are unsure of the coil ohms,, take an ohmmeter, disconnect one of the terminals from the coil and read the meter with the meter leads across both terminals, there should be about 3-4 ohms reading or in that area. Generally if a resistor is used in the original circuit it is a low ohms coil-about 1.5 or in that area and the resistor must be retained or a coil with the proper ohms substituted, personally I would invest in the coil that is recommended for that unit, it will have the proper ohms to protectr the module and will have a higher secondary voltage output. Once installed and running do not remove a spark plug wire to check spark as spark can jump down the coil tower to the Pertronics connections and damage the module. Experience speaking. mEl

Mark, good advice from Bob & Mel... As far as the plug wires, if you dont change the plug gap they are gonna fire at pretty much the same voltage as before so the old wires (IF in good shape) or 7 or 8 mm either would work fine.

What many people do when they add an elec switch to get the most bang for the buck is to match it up with a high energy higher voltage capacity coil and widen the plug gap. In that case you need good quality insulation wires so the higher operating voltages wont arc over somewhere buttttttttttt still even good quality stock wires or 7 or 8 mm EITHER will still work fine on your tractor. If you get into race cars and run say over a 0.050 plug gap and are at extreme high compressions thats when firing voltages can go wayyyyy up and you might need those 8 mm wires.

Id dont see any need to change the heat range of the plugs, thats a function of the reach and other factors having to do with heat dissipation which the elec ignition dont change much if any at all.....

As far as the gap if you use a stock coil I wouldnt change it much. If you wanna go with a high voltage coil you can widen the gap a bit more as it has the capacity to achieve higher firing voltages, but still even the stock coil can reach high enough to fire at a wider gap unless hou go crazy and open it realllllllll wideeeeeeeeee...

Id still match the switch with a high energy high voltage coil n run a wider gap that way you get the most bang for the buck that elec switch has to offer

BE SURE AND CHECK WITH PERTRONIX ABOUT THE NEED FOR ANY EXTERNAL BALLAST (does tractor have a ballast now or not) and get the polarity correct so you dont fry the new switch. The switch has a certain ampacity so the coil and/or coil and ballast combination cant be such that its exceeded.

John T

Yo Bob, we may have to arm wrestle some here lol I outweigh you I may have an advantage !!!!

I wouldnt agree with you the pertronix "provides a higher voltage spark" Id say it still fires at the same voltage UNLESS the plug gap is increased or the compression is raised. If he used a HV coil then Id say that system (but thats still so even if points are still used) has the CAPACITY TO FIRE AT A HIGHER VOLTAGE in the case the gap was increased or compression raised......

The elec switch provides a faster more positive switching with no points bounce and ringing is what it does really IN MY OPINION PLUS it has the capacity to switch more current (like if a High energy coil is used) the points and NOT burn or deteriorate like points as you talk about

Nowwwwwwww with a non deteriorating faster more positive coil current switch (then with points) even with a stock coil the spark can be stronger buttttttttt if the elec switch can handle more current one can use a higher energy coil and if the coil is also HV rated one can also run a wider plug gap FOR A FAT WIDER HOTTER MORE ENERGY DISCHARGE SPARK wooooooooo hoooooooo and thats when the elec switch really shines

So whatcha think Bob Isnt the plugs firing voltage a function of the medium (fuel and compression) and plug gap distance??????? And if neither is changed, why dont the elec switch fire at the same voltage ??????? Perhaps the ramp up is a bit faster but the voltage across the gap ONLY rises high enough to arc current across the gap AND NO HIGHER and it dont know if points or an elec switch turned the coil current off right???????


Talk to me !! Thats my story n Ima stickin to it unless you can show me otherwise, hey Ive been wrong before, just cant rememebr when lol lol lol

Ol John T and all

Thanks John T., As always great info. I hope you and Bob M. work things out!!!!!! You both are talking way over my head on some of this stuff. But I bet I can make it work. Thanks!!!!!!

Thanks for the info. I will need to check my coil or change it to the one that goes with the kit. It does have a resistor. If I change the coil to the right one (3-4 ohms) can I remove the resistor?

Bob and I are good friends, Im just havin a lil fun with him......hes a Mechanical Engineer and Im an Electrical so its an age old friendly rivalry .......In general if you go with a full true 12 volt coil it has around 3 or so ohms priamry resistance and I think the standard pertronix elec switch can handle that 4 resultant amps so a ballast wouldnt be needed BUTTTTTTT always check with pertronic because on some of their coils (lower resistance ones) I think they may still recommend an external ballast, it depends on what coil you have, although if you use a stock 12 volt 3 ohm coil none should be needed........AGAIN CONSULT PERTRONIX ABOUT THAT STUFF NOTTTTTTTTT MEEEEEEEEE

John T

JohnT, It is interesting to note that there is a different requirement for a 4 cyl vs a 6 cyl with the Pertronics switch, all covered in the installation instructions. A 6 cyl would not require a resistor while a 4 cyl would. I guess the "dwell" of a 4 cyl unit allows more heating than a 6 cyl due to the difference in the frequency of switching. Anyway, the pertronics has very clear and concise directions contained in the customer instructions info avoid these problems. I suggest not cheating on them. I still contend a proper way to proceed would be to buy the recommended coil to match. mEl

Good point AND I AGREE, thats why I always advise people to CHECK WITH PERTRONIX and to be sure to match the coil and switch for compatibility when buying any of those high performance pertronix coils....

Fun discussion

John T

Be sure to check and double check the ohms on that coil. I just had the pertronix unit fry on my Willys jeep. Seems something let loose in the coil and I had no resistance at all. Pertronix told me that 3-4.5 ohms is the range their units work in.

Hey John - I agree with you 100% - despite your preference being toward those GREEN tractors(!).

I could have better explaining my statement about the Pertronix and its higher voltage spark. I should perhaps written this:

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The Pertonix has the CAPABILITY to provide a higher voltage spark. However unless the gap at the spark is opened up, the spark voltage seen at the plugs is unchanged with the Pertronix.

However the Pertonix' higher voltage capability can be utilized to reliably jump a LONGER spark gap. Also with the right coil the Pertronix can produce a greater spark current. This combines to develop at a longer, hotter spark in the combustion chamber. This in turn provides more reliable better ignition of the fuel/air mixture - particularly if the mixture is a slightly rich or lean.

(This incidentally is what drove car manufacturers to electronic ignition in the 1970's - the ability to fire a leaner than ideal mixture. The longer and hotter spark the spark, the more fuel mixture is initially ignited, and thus a flame reliably propogated through the entire fuel/air charge.)

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The Pertronix is not without a few disadvantages however:

If other ignition components - plug wires, distributor cap, external plug insulators, etc - not in good shape, increasing the plug gap so higher voltage can be developed at the plugs may result in the spark jumping someplace other that at the plug gap. (We learned this on the 3020 with a worn out distributor cap on a damp morning.)

Likewise old, worn out plug wires and dirty external plug insulators will make then engine look like a July 4 fireworks display in the dark as stray HV current dances over this stuff.

Also if the engine has other issues causing it to foul plugs/misfire (rich carb, oil burning, low compression, sloppy distributor drive, etc) the Pertronix will not improve the situation any.

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Make sense John???

Bob