When installing any ignition into a racing engine that has had the cylinder heads milled and block deck milled, or even an intake manifold change, you should install the magneto or distributor into the engine without any gaskets to make sure the ignition unit doesn't bottom out on the oil pump drive and cause a bind. On some big blocks the bottom of the gear will hit inside the engine block if allowed to go down too far and either one of these problems can bind the magneto or distributor up and cause damage to the mags thrust washer and more than likely cause the magneto to retard out of time. If you run into this situation we have low cost shim kits to raise the ignition unit up a small amount or magsarus can install a fully adjustable slip collar on the vertex mag so the mag will fit into any chevy v8 engine from s.b.c.to b.b.c., standard cam location to raised cams, low deck blocks or high deck blocks.
The next thing that is important is to check the mag gear to the cam gear position. For this you need to get some machinist blue dye, or some white grease works or a magic marker. Paint the mag gear, Reinstall the mag into the engine, Rotate the engine over a couple of times, Remove the ignition and look for the mesh marks on the gear and just shim or adjust the slip collar up or down as needed so the cam gear will be driving the ignition gear in the center.
The number one cause of premature wear on the drive gear brass or steel, magneto or distributor is excessive resistance from driving the oil pump Every time you start the engine up with cold 50W oil these engines can produce as much as 80 to100 psi at idle. It is very important to keep the RPM's low until you get the proper oil temperature, or the proper thing to do is to preheat the oil, early in the year when the outside temperature is down to 50 degrees it takes a lot longer to get to 200 degrees. The biggest selling oil for steel block engines with minimum bearing clearances is a 10/30 synthetic. This oil is easy on the oil pumps and distributor gears and will make more H.P.
Now with engines that use external oil pumps you won't get any wear on the magneto drive gear and you can expect to get a good 10,000 laps on a circle track engine on one gear, whereas with an internal oil pump engine you usually can expect to replace it every 1200 laps, a noticeable difference. and there is also some low cost cam cores that have a poor machine finish on the cam shaft gear that is eating up distributor / mag gears in dry sump engines. you can tell if you have one of these cams as the rough machined finish will show up in the ignition gear where it is wearing the ignition gear out.
Ignition wires are a subject that a lot of racers ask about, for instance, what brand, spiral core, copper core, stainless steel core, armiad core, carbon core etc. Well I like to keep things as simple as possible so my suggestion is to use 8mm solid copper core wires for a perfectly simple reason and that is when you go out and purchase a new ignition that is putting out more voltage and more amperage, why would you ever want to put a resistor between the ignition and the spark plug, and that is just what all of those wires do except for the copper core or the stainless steel core. These spiral core wires suck up the amperage before it reaches the spark plug and in turn makes a weak ignition. 10 mm wires are not going to perform any better than 8mm wires.
The one thing to remember, copper is the number one electrical conductor. It is used everywhere for everything in conducting electricity. Resistant spark plug wire like the spiral core absorbs lots of amperage before it reaches the spark plug. Some ignition systems have to use these wires because the electrical magnetic field produced around the wires is strong enough to send bad signals to the electronic boxes. With Magnetos and our racing HEI distributors, there isn't any problems in the performance, it is better. And I have not seen any problem with these wires affecting the msd rev limiters that some of the sportsman classes have to use in our area.
Problems can a cure when you have high voltages being induced and removed from a conductor. when you feed a spark plug wire with high voltages it creates a magnetic field around each spark plug wire , when the voltage passes through #5 spark plug wire on a Chevy engine as the electrical magnetic field collapses it will collapse into the wire that is closest and parallel to. If it happens to be the #7 wire, it could possibly fire #7 cylinder under perfect conditions and at that point in time #7 piston is way down in the cylinder, and if it happened to ignite this cylinder, it would try to push the piston backwards and creating a problem. Just remember to space your #5 and # 7 wires or on the c fireing order cams you need to space #1 and # 3 wires the rest of the wires I like to just let them hang or criss cross them so they are not parallel to each other.
All spark plug wires will burn when placed on 1,200 degree headers, so make sure boots grip the spark plugs well, otherwise they will fall off during the race; that is really all on ignition wires. if you install or put new boots on spark plug wires you should use a silicone dielectric grease. And on my engines I will run my number one wire across the top of the engine and down the front of the head and up to the spark plug. this does two things the first is it gives you easy access for timing the engine and it gets the wire away from all other plug wires for a good accurate timing light signal.
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