LISTED BELOW, YOU WILL FIND SOME COMMON TOPICS DISCUSSED IN THE RACING ENGINE WORLD.  FOLLOWING EACH TOPIC IS A BRIEF DESCRIPTION TO HELP BETTER UNDERSTAND EACH SUBJECT.

DETONATION

DETONATION IS THE SPONTANEOUS COMBUSTION OF THE REMAINING AIR/FUEL MIXTURE IN THE CHAMBER.  IT ALWAYS OCCURS AFTER NORMAL COMBUSTION IS INITIATED BY THE SPARK PLUG.  THE INITIAL COMBUSTION AT THE SPARK PLUG IS FOLLOWED BY A NORMAL COMBUSTION BURN.  FOR SOME REASON, LIKELY HEAT AND PRESSURE, THE END GAS IN THE CHAMBER SPONTANEOUSLY COMBUSTS.  THE KEY POINT IS THAT DETONATION OCCURS AFTER YOU HAVE INITIATED NORMAL COMBUSTION WITH THE SPARK PLUG.

PRE-IGNITION

PRE-IGNITION IS THE IGNITION OF THE AIR/FUEL MIXTURE PRIOR TO THE SPARK PLUG FIRING. ANYTIME SOMETHING CAUSES THE MIXTURE IN THE CHAMBER TO IGNITE PRIOR TO THE SPARK EVENT IT IS CLASSIFIED AS PRE-IGNITION. 

BRAKE SPECIFIC FUEL CONSUMPTION

BSFC IS AN INDICATOR OF FUEL EFFICIENCY.  IT TELLS US HOW MUCH FUEL THE ENGINE IS CONSUMING TO MAKE ONE HORSEPOWER FOR ONE HOUR.  BSFC IS CALCULATED IN POUNDS SINCE FUELS WITH VARYING DENSITIES HAVE DIFFERENT VOLUMES.  AS AN EXAMPLE, AN ENGINE WITH A BSFC OF .500 WILL BE CONSUMING 1/2 POUND OF FUEL PER HOUR FOR  EVERY ONE HORSEPOWER IT GENERATES.

SPECIFIC GRAVITY

SPECIFIC GRAVITY IS THE RATIO OF THE MASS OF A LIQUID TO THE MASS OF AN EQUAL VOLUME OF DISTILLED WATER AT 64 DEGREES FARENHEIT, WHICH IS REPRESENTED BY 1.000 SG ON A FUEL CHART.  FOR EXAMPLE, PURE METHANOL HAS A SPECIFIC GRAVITY OF .795 @ 60'F, AND PURE NITROMETHANE'S SG IS 1.139 @ 60'F.

VOLUMETRIC EFFICIENCY

AN ENGINE'S VOLUMETRIC EFFICIENCY IS A RATIO OF THE AIR THAT IS ACTUALLY ENTERING THE ENGINE DURING OPERATION TO THE AMOUNT OF AIR THAT SHOULD THEORETICALLY BE ENTERING THE ENGINE, BASED UPON THE VOLUME OF THE CYLINDERS.