Tune up

Previously we talked about how to go about an engine tune-up involving older cars with distributors: both contact-point type and those with electronic ignition. The concern on what spark plug to use was limited to using stock or OEM (original equipment manufacturer) spec units. With current engines having longer tune-up intervals because of newer types of spark plugs and ignition systems, some have asked if the older cars could benefit from these newer items. The answer is yes. One of the ways to increase engine efficiency is to burn the air and fuel mixture better. Having a more reliable spark can give the engine a more consistent performance. And also better fuel economy.  In the past few years, spark plug manufacturers have come out with spark plugs that can burn better and last longer. Splitfire came out with a spark plug with a notch at the ground electrode. It’s supposed to increase the burn area that burns more air and fuel mixture. Then came the ones with multiple ground electrode. This design also promised larger burning area. Now you the iridium cored spark plug. Smaller center electrode, longer lasting. Then things got more interesting.

For those with older engines, they said that it was bad for your engine because it had a tendency to overheat. True… I agree. But that’s where tuning your engine comes in. The extra heat generated comes from the same amount air/fuel mixture that enters the chamber but this time, more of it is burned. How is that? Lets say an ounce of air and fuel enters the chamber. And upon combustion 90 percent of the mixture is burned and certain amount of heat is also generated. Lets say that makes 9 pounds of force. The 10 percent is thrown out of the chamber as unburned gases. If you increase the burn efficiency by 3 percent, then more air/fuel mixture will be burned. Then more heat is generated, more power. Your unburned gases is down to 7 percent. That’s why your engine temp will rise. More power, more heat generated. For fuel efficiency, you would need lesser fuel to produce 9 pounds of force because you can burn the fuel better. For the ones with carbureted engines, you would need to adjust your primary and secondary jets.