Be careful with external oil lines if you are racing a dry-sump engine. If these lines are
We've already covered what happens if you get the leads to your distributor crossed, but there are also a number of other factors that can cause an engine to mysteriously start skipping or missing on the racetrack. And often, it's not the ignition system but something else.
If you can't find the source of a miss on the racetrack, try looking at the other areas of the car's electrical system. A dying battery can often be a problem, even if you are running an alternator. And this one may not be obvious, but check the battery kill switch. Corrosion or bad contacts there can severely limit the amount of current getting through. The same thing goes with your electrical ground. Many racers use a couple different ground straps in the race car to try to avoid a problem here. Also, make sure your ground strap is connected to bare metal on the chassis. If it is attached over painted or powdercoated metal it simply can't work as efficiently.
Finally, Dorton recommends checking the wiring to the alternator. In order for the alternator to work as intended, it needs a pretty large cable to route the power it has generated through. Standard electrical wire like you used for the ignition switch simply isn't large enough. Dorton says the cable should be 1/4- to 3/8-inch thick and look more like a small battery cable than standard electrical wiring.
Poor Fuel Mileage
Most race classes don't require pit stops for refueling under green, but fuel mileage often does come into play whenever a track has extra-lap features, or the big-money races at the end of the season that can be 100 laps or more. And nothing can be more frustrating than running out of fuel when you are running well.
See those posts sticking up from the carburetor? Those are the vent tubes, and they have t
The first reaction normally is to blame the carburetor for being poorly tuned and extra thirsty. But before you round up an angry mob to scare the pants off of your carb tuner, take a moment to make sure you aren't leaving fuel in your race car. This requires pulling your fuel cell apart to make sure the pickup is situated correctly in the bottom of the cell.
Sometimes, especially when repacking the cell, the pickup can get moved around or a chunk of foam can get underneath the pickup so that you run "dry" when there is still a gallon or two of fuel still in the fuel cell. Also, check your rule book and make sure you are using the largest fuel line, fuel filter, and fuel filler line allowed. Dorton says that using a No. 12 fuel line from the fuel cell to the fuel pump instead of a No. 6 can get you an extra 1/2 quart or more of fuel, which can be the difference between a strong finish and getting pushed back to the pits.
While we are talking about fuel systems, let's pick up on a problem that actually does involve the carb. One mistake some racers can make is to put the carburetor on the intake, make sure everything works and the throttle doesn't hang up, plop on the air cleaner, and then forget about it.
And there is actually a critical clearance between the carburetor and the top of the air cleaner that you must be aware of. If the air cleaner lid is too close to the top of the carburetor, it can block the inlets for the vent tubes. Generally, the vent tubes need at least 1/2-inch of clearance or it can cause the engine to stumble at wide open throttle. If this is happening to you, try a taller air-cleaner element and see if it fixes the problem.
There you have it; eight engine tips to keep you on track and out of trouble.