Page 22 - Combined_141_OCR

READING CHAMPION RACING SPARK PLUGS

(Champion Spark Plugs Only)
With practice and proper magnification (4X to 6X power), pits or paddock, or on the drag strip return line will erase
plug firing end condition will pinpoint engine ailments... all plug readings.
and measure the condition and performance of a race engine. Tachometer . . . engine temperature ... oil pressure . . .
Properly-interpreted plugs will indicate if a race engine and fuel pressure gauge readings are also invaluable in
is loafing or extracting full horsepower... they will also compiling an overall indication of engine performance dur­
reveal if the ignition system, engine oil control, timing and ing practice or trials.
carburetion are correct. Acceleration, general engine response in turns or esses
Precise tell-tale readings require knowledge of which plug or long straights should be relayed by the driver during prac­
was removed from which cylinder and which carburetor (or tice and tied in with spark plug analysis.
venturi) or injector feeds which cylinder. Of paramount importance. If every spark plug is not the
Readings must be taken at maximum power output. It is same general condition or color, the engine is not producing
imperative that the engine be shut clean. The ignition must full horsepower. Plug coloring is discussed on page 41. Plug
be cut off at full power and the engine de-clutched with suf­ conditions are illustrated here... learn them. Many of the
ficient momentum to coast into the pits or come to a stop indications refer only to the design nature of Champion
near the end of the drag strip. A car that is driven into the spark plugs.
Normal Overheated Insulator nose blistered
Electrodes or chalky white • dark
are not discolored brown spots on nose • or
Excessive “cement
boil” around center nose has satin-like sheen
electrode (milky white Side electrode blued
excess or meringue-like near end or breaking
color formation)
up in structure
Center electrode
rounded off at
edges • blue °
partially eroded ’
or breaking up
in structure
INDICATIONS: Strong Ignition. • Proper Mixture Lean Mixture • Excessive Spark Advance
Good Oil Control • Proper Heat Range INDICATIONS: Inadequate Engine Cooling • Wrong Heat Range
Detonation • Incipient Preignition
Detonation Evidence
“pepper specks” on
ator nose or electrodes
Exposed shell
surfaces speckled Excessive
“cement boil”

Note: Tiny aluminum
beads on nose may
indicate metal is __
starting to leave
Engine Too “Loose” • Ring Not Seated
INDICATIONS: Broken Ring • Broken Valve or Spring piston crown
Valve Guide Worn • Detonation
EMERGENCY CORRECTIONS: Richen Up (See page 27) Retard Spark
“Spark Mark” Burnished, highly polished
areas where spark has
jumped across electrodes
of strong

Usually “new moon
INDICATIONS- Overrich • Weak Ignition • Misfiring Plug shape” on center
Wrong Heat Range • Defective Cables electrode
42 43