Ford m-6007-xefms Manual De Usuario

 

 

NO PART OF THIS DOCUMENT MAY BE REPRODUCED WITHOUT PRIOR AGREEMENT AND WRITTEN PERMISSION OF  

FORD RACING PERFORMANCE PARTS. 

 

IS-1850-0179 

 

Page 3 of 13 

 
IGNITION SYSTEM CONSIDERATIONS/COMMON PROBLEMS 
 
The ignition system must deliver a properly timed spark. There are a lot of factors that determine when the spark 
should be delivered. The most common factors include: compression ratio, fuel quality, fuel octane rating, 
combustion chamber design, engine operating temperature, power adders such as NOS or supercharger, inlet air 
temp, altitude, and load.  
 

•  Avoid too much or too little timing for your engine combination. 
 
•  Avoid hooking up the vacuum advance to intake manifold vacuum instead of ported vacuum. 

 

•  Avoid inductive crossfire created by improper plug wire routing. Separate plug wires on cylinders that fire 

in sequence. 

 

•  Improper timing can damage pistons, rod bearings, head gaskets, and many other engine parts. 
 

•  Typical total mechanical advance timing at 4000 rpm for Ford Racing Performance Parts crate engines: 

5.0L - 36° to 38° With factory EFI, 14 to 16 degrees initial. 

FUEL DELIVERY CONSIDERATIONS 
 
Size of fuel pump, size of fuel line, fuel pump placement, fuel filter placement, fuel filter size, injector size, fuel rail size, 
fuel pressure, jet size, and baffling in the fuel tank.  

Does the fuel system maintain full pressure at peak engine horsepower in high gear? Altitude, air temperature, and 
fuel characteristics including quality, specific gravity, and octane rating, will affect your jetting requirements. Engine 
efficiency and Brake Specific Fuel Consumption (BSFC) also have an effect. Here are some examples of a Holley 
750 CFM 4V. 

 

Jetting 

Jetting 

Octane 

Temp. 

Elevation 

Front 

Rear 

94 80 

F 

Sea 

level 

81 

86 

Aviation 100LL 

80 F 

Sea level 

81 

84 

110 Race 

80 F 

Sea level 

78 

83 

94 

80 F 

3000 ft. 

76 

81 

94 

80 F 

6000 ft. 

73 

77 

94 40 

F 

Sea 

level 

84 

89 

94 120 

F 

Sea 

level 

78 

83 

 

As you can see by these examples, jet requirements can vary a lot depending on fuel, altitude, and temperature. 
Oxygenated fuels are available in some states and can dramatically affect your jetting requirements. Make sure you 
get your jetting correct.