by E. Meloan
(This article was originally published in the September, 2002 issue of the Spark Coil.)
Continuing last issue’s tips for new T drivers…
Setting the spark and fuel mixture correctly is very important to prevent engine overheating and fouling!
Start the car with the spark retarded but drive with it advanced as much as possible without causing spark knock! In a car with the timer positioned correctly, the spark lever will usually produce the best results when advanced more than half way down the quadrant. Some folks like to set their timer position to produce maximum high speed power when the spark lever is pulled all the way down. You can usually tell the point at which the spark timing produces the most power. Going further, you will begin to feel a loss of energy.
Running with the spark too retarded will quickly cause the engine temperature to rise. When in a parade, we all like to retard the engine to get that nice distinctive Model T idle that sounds SO good. But when we do that, the engine temperature will rise fairly rapidly. Since we are barely moving, a parade is a challenge for the cooling system under the best of conditions. Retarding the spark makes the system work much harder to cool.
If you like to retard the spark, watch your MotoMeter or temperature gauge and when the temperature begins to climb past normal, advance the spark and give the engine a chance to cool back down. I always wonder how many folks who have over-heating problems in parades are running with the spark retarded to show off that neat “T” sound.
Another cause of overheating that is frequently overlooked is the fuel mixture. Running with the fuel set too lean will cause a loss of power and increase in engine operating temperature. Setting the mixture richer will
cause a noticeable decrease in engine temperature. Setting it too rich is not a good idea either because too rich a mixture will cause sooting and rapid plug fouling.
See you down the road…