We are new to the religion that are Magnetos so we need some advise from the Gods and Gurus out there. What are the recommendations for a Magneto - kill / On - switch for the driver? What are the recommendations for a Power / Magneto kill switch at the back of the car ? I already have a basic kill switch for the battery / power. Is there anything (like a solenoid) that can be added to the basic kill switch ? Schematics would be appreciated - even if it's just a link Flaming River makes a Mag / Power switch for the back of the car (with and without rod) but I'm not sure I want to spend $140+ on it. Thanks in advance folks I'll advise how it all works out if we don't stun-gun ourselves sorting out the Buzz box !!
Magneto does not have any power going to it, the kill switch is connected to the mag and to earth. Do not connect power to the mag.
Fully understand that the mag creates it's own power and I should not attach power to it (Bad...very bad) but I see a need to kill the ignition in the event of a mishap and the fuel shut off for the fuel injection (which we are running) cannot be reached. I guess, after re-reading your answer, I set up a ground system. I was hoping folks would show me how they did it for some inspiration The Flaming River unit integrates the mag "ground/kill" into the power kill switch. I'm looking for an alternative to this using a standard kill switch and ??? So...I guess I should have stated it as ... how do you guys set up a ground to kill the Mag... or something like that
You could run 2 wires of the mag, to 2 kill switches one in the cab for the driver and one out side for emergency shut down.
I run a two switches wired in parallel. First switch (in the car) has one of those air craft covers that makes it REAL easy for the driver to see and shut off even with gloves on. The second switch is mounted to the back of the car - it is a momentary switch that must be held to kill the motor.
saxxon, im glad you brought this up, im putting a mag on a slingshot project, and been thinking about the same thing on what switches to use. i read what hemirambler said about a momentary switch on the rear of the car, but im concerned about a situation like what happened at the meltdown last year where the car crashed and throttle wide open, car in gear and either no kill switch at rear of car, or no one could get close to it because tires were spinning. bad deal no doubt, but whats the best switch to use? if its momentary in that deal you couldnt stand that close to hold switch down until car died.last i heard the driver was ok, but it was scary.
I have the same issue you have,needing a outside kill. A relay is the only thing I can think of that would allow you to do that. If you wire it so when power is off or down it would go to ground,in the open position. Power is applied and relay is closed,it would open the circuit allowing the mag to run. Any power loss to the relay would kill the mag. Either ignition sw or aux batt kill. Any better ideas out there ? Always open for suggestions. (Edit)Ahhhh,the charging system might be the axe in the head. A diode to the relay may be needed so the charging system doesn't keep it on when the batt is killed.
Correct, only IF the ignition is powered by the battery. Magnetos develop their own power (no battery required), so they are SHORTED to ground in order to kill the engine. In the case of a magneto, two switches in PARALLEL are the answer. The relay idea in effect would have the relay as the second switch in parallel. Using the NC (normally closed) side of it would kill the engine when battery power is removed. Be sure to consider the 'air gap' of the switches (and relays) - magnetos can develop pretty high primary voltages that can jump the contacts, resulting in an ignition misfire. I learned this way back in my go-cart days....
Make sure the switch you use has enough air gap in it, some Mags have enough power to Weld the contacts together and the switch goes up in a ball of Fire, found this out the Hard way after I got my Mag recharged , the switch was inline with the fire window in the firewall and I thought the motor blew, the fireball was so big !! they make a Mag kill switch with a 5/8 airgap, after I got one ,no more Fireballs ! Chris
Here is what I do. I used to work at Flaming River, it is the best switch out. I use the standard cut off switch with my magneto and just buy the painless magneto relay. Its the easiest way to go. Let me know if you need a switch, I can still get good pricing. I would also look at doing the push off kit, a twist switch isnt really NHRA accepted, plus, you can barely see a pushrod on the back of the car. Beware of the cheap china switches.
I have never used anything more then a toggle switch for a kill switch, for racing where you need a rear mounted kill switch just get a setup already built for the system. you can buy them because real race cars (not to say that yours isn't) run mags. Maybe contact your favorite catalog speed shop or if you don't have one PM me for mine.
If you want to know anything about magnetos, talk to Pat Mason @ Mason Racing in Schwenksville, PA. He fixed me up with everything I needed for my mag setup.
Not series, parallel. You need to ground out the mag. You are not opening a circuit you are closing it.
I used (2) new MSD magneto switches, one in the car and one on the back. The switches are toggle and they were pretty expensive....around $50 each but designed for magneto grounding. Either switch will kill the mag when grounded. I have (1) Mallory mag switch with On-Off-Boost positions....I have no idea what "boost" is for but if you need the switch let me know.
I run Division III NHRA Super Pro. Here is what I have done that passes tech at every track I've raced at (and believe me - you will get checked to make sure the master cutoff switch at the rear of the car will kill the mag): Wire a standard five-pin relay - like those used on fans, horns, etc. so that it is hot when the master switch is on AND the ignition switch (the one that powers up the tach, starter motor circuit, pumps, fans, etc) is on. When the master switch is pushed off that sends the mag circuit to ground. A separate in-cockpit "mag kill" switch is wired in parallel to the relay ground circuit to kill the mag in the car. I also have a separate in-car master cutoff switch that also kills EVERYTHING in one motion. Once upon a time it kept me from hurting many spectators... ...but that's a whole 'nother story.
It will help to have a little better understanding of what is going on inside the magneto. In fact it is not much different from a typical auto ignition setup. It is just self contained excepting the run/stop switch. Inside there is a coil with primary and secondary windings. The Secondary coil's finish end wire goes to the distributor section of unit and then on to the spark-plugs, while its start end wire is grounded. The Primary coil has its start end wire grounded as well while its finish end is terminated to an insulated contact post that is part of the points mechanism. The Primary's finish wire is also connected to an insulated external binding post for the purpose of shorting out the primary coil and points mechanism. The moving magnet in the unit will induce a current in the primary coil as long as the points are closed. When the primary circuit is broken is when the secondary coil produces its voltage "spike". The moving magnet can produce considerable voltage in the primary as well but not more than a 100 volts or so. Enough to give you a "bite" but not enough to arc across a .035 plug gap. The air gap discussion and fireballs is an indication something else not right with the lash up. The most overlooked provision of magneto setups no matter what switch is used is lack of capacitors across the kill switch. This is essential to avoid burning the contacts from arcing when switch is closed. The importance of this is overlooked by most. Just like the points in a standard ignition system, burned points won't induce voltage in the coil, likewise burned points may not conduct the ground needed to disable the mag. In an emergency we don't want the possibility of burned points preventing an engine shutdown. The economical solution is to place a minimum .1uf @ 400vdc across all you switches. This will eliminate arcing and the possibility of burned contacts as well as insuring longevity of your switches. Best Regards and Good Luck with all your endeavors, KB.
And don't forget to use a large gage, good quality wire. Back when I was racing, I ran a 12 gage wire on my Vertex powered s.b.Chevy powered Anglia. It was not reliable. I changed to a steel core spark plug wire as the ground thru a 20amp switch, never had a problem after that. So a plug wire to an NHRA accepted switch would work well. Mike
I see that you are in Winnipeg. You could contact Spud Miller at Fuel Injection Enterprises. He is in Oregon. He builds and services mags and fuel injection. He took over the Mallory mag service business. He also runs a injected nitro dragster. fuelinjectionent.com. 541-990-2485. Email: [email protected].
Thank you I've been running a 15 amp Super Mag kill switch from Good Vibrations for the last 3 years with no issues. Myself and a friend have also dealt with Spud / FIE since we both went to a magneto
buy a new ignition(mag) switch for a 1940 or so Farmall m tractor. make sure you get one for the engine with magneto ignition. it just grounds the out put of the mag generator.
just have to add this. when I was a kid(long time ago) we had a farmer neighbor that had a Farmall M tractor. it had the 6 volt battery ignition system. He could kill the engine by placing his fingers on each of the 4 spark plugs wires at the spark plugs. He ccould not do it to an M with the mag ignition, too much juice!
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