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High Octane Mixing & Water Injection

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In my opinion, the main reason hydrogen garners attention as an alternative fuel is because it offers reduced emissions. By eliminating carbon (gasoline is a hydrocarbon fuel), the main emission components resulting from the combustion of hydrogen is water and oxides of nitrogen. Since hydrogen does not occur naturally, it must be created artificially by applying energy to disassociate water into its two major components of hydrogen and oxygen. As a performance fuel, hydrogen is just not a good idea. Add to the fact that it is easily flammable and there are no inexpensive ways to transfer the fuel, and you can see why hydrogen has never really caught on. Conversely, E85 is a far better alternative fuel, as it enjoys a 105-octane rating, is a liquid fuel and a renewable resource (although it too requires energy to create), and it works extraordinarily well in performance applications, especially in super- or turbocharged engines. But that's just my somewhat prejudiced opinion. The price of E85 has also risen lately, mainly due to the loss of government incentive programs. We priced E85 with a 105-octane rating locally at about 75 cents a gallon cheaper than regular 87-octane pump gas.

More Info

Kurt Urban Performance; Clayton, NC; 919/938-1771; KurtUrbanPerformance.com

Voltage Variations

Glen Hiller; via CarCraft.com: I have an ignition question for you. I have a '69 Chevelle big-block and all the go fast goodies, such as a 750-cfm Demon, a dual-plane intake, 11:1 compression (with a 50/50 mix of 93-octane and VP C12), a 3-inch exhaust, and a blueprinted HEI. Years ago, I replaced the resistor wire that feeds the distributor because I was getting a popcorn-popping backfire when I would open it up on the highway. I replaced the wire with a nice, big 10-gauge copper wire that went directly into the distributor. Problem solved. However, after a few years, the popping started again, but only on long, uphill stretches. What is this new PerTronix relay kit that replaces the resistor wire? Will it do anything different than I have already done?

Jeff Smith: That's a great question, Glen. My guess is that the relay may not really change much, but there's a simple way to check if your wiring modification was completely successful. The test is to start the engine and use a multimeter to read the voltage at idle on the output terminal of the alternator. Let's use 14 volts as that number. Now use the voltmeter to read the voltage at the distributor. If the reading is within half a volt of the power coming from the alternator, then this is not your problem. However, if the reading is 13.5 volts or lower, then there is resistance somewhere in the long, circuitous route that the current must travel to reach the distributor. It's possible that it reads 12.5 volts or less, depending on how much resistance is in the circuit. As the voltage drops, the potential power output of your HEI ignition reduces, and that could be the source of your misfire under load. It's important to mention that higher- compression engines and any super-or turbocharged engine create high cylinder pressures. This additional pressure requires more initial voltage at the spark plug to ionize the air path between the spark plug's center electrode and the ground strap. Lower-feed voltage to the distributor will drastically reduce the maximum voltage at the spark plugs.

Back in the day, all three major car companies used some kind of resistance circuit (GM and Ford used a resistor wire; Chrysler employed a ballast resistor) to reduce the voltage to the points. This was done because 12 to 14 volts would quickly burn up a set of ignition points. The reason the HEI was such a major improvement was because it used all the 14-volt input. Often what happens is the installer will cut that resistor wire off and use a switched 12-volt wire from the fuse box to the HEI. It's a safe bet you are still using the original wiring harness in your Chevelle, which is probably a bit crusty at age 43. These old circuits can build resistance, so it's possible there is some resistance in that circuit. That's where the PerTronix relay (PN 2001, $29.95 Summit Racing) can be beneficial. Relays pull voltage from a clean power source such as from the horn relay or near the alternator-output terminal, so you can use that original, switched, 12-volt wire from the fuse box to trigger the relay. This does not have to be full-system voltage, since you are only using it as a trigger for the relay. There are only four wires to connect, and we've included a small drawing to show how simple it is. We like the Bosch 30-amp relays, but any quality relay and wiring harness will do the same job. The PerTronix unit was originally intended to be used with the PerTronix point conversion, which works better when fed full-system voltage, much like the HEI.

Relays such as this can be used for all kinds of electrical applications in older muscle cars. A classic example is using a pair of 30-amp relays to eliminate the major voltage drop that occurs in the headlight circuit. By using the headlight switch to trigger the relay, full-system voltage is fed to the headlights. In the stock situation, it's common to measure barely 11 volts that actually reaches the headlights.

More Info

PerTronix; San Dimas, CA; 909/599-5955; Pertronix.com

Summit Racing; Akron, OH; 800/ 230-3030; SummitRacing.com

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6 comments
David J Miller
David J Miller

thought the idea was to keep the wheels on the ground moving the car forward down the track pass!

Timothy Bremm
Timothy Bremm

Leaf spring car a torsion bar in the rear...depends on how much horsepower to the rear wheels.

jdr98stc
jdr98stc

I would like to know if the stock fuel line in a 1966 Mustang, will support a near 500 horsepower, Ford Racing, 363 cubic inch, crate motor. Any information or suggestions would be appreciated. Thanks, Joe

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