Motor Modifications

• Controlling the valves that control the amount of fuel entering each cylinder, the 383's camshaft is finely tuned for high performance. Higher cam ratios mean a larger port, which allows more fuel to burn per cylinder firing sequence. As a result, the 383 Stroker can produce between 330 and 600 horsepower. The higher quantity of fuel-air mix used by this motor affect the timing specifications. Because this engine can be outfitted with many high-performance options, the timing specifications must be tuned to the individual motor.
  
  

Pistons and Compression Ratios

• The larger crankshaft also translates into higher compression ratios, and a piston that compresses the gas-air fluids more quickly. A typical Stroker motor features a 9.2-to-1 compression ratio. When the fuel-air solution is ignited under higher compression conditions, the resulting explosion releases higher energy levels at a greater efficiency than a more conservatively rated engine. The ignition timing controls exactly when the cylinder spark plug fires in quarter to create maximum performance from each firing sequence.
  
  

Initial Timing Settings

• The 383 Stroker engine's timing specification is 8 degrees before top dead center (BTDC). This means that the distributor cap sends a message to the cylinder's spark plug to fire when the crankshaft is 8° before reaching the top dead center, which is the maximum compression in each cylinder. The distributor cap initiates the spark plug firing before top dead center because momentum in the crankshaft and the delay caused by resistance in the spark plug wires allow the piston to travel to top dead center position before the spark plug actually fires.
  
  

Fine Tuning the Engine's Timing

• Because of the high number of options available on the 383 Stroker, the motor's timing should be fine-tuned with an automotive diagnostic computer. Optimal performance will be obtained when the final timing is adjusted to somewhere between 4° BTDC and 8° BTDC. Factors that will affect the engine's final setting include the engine's carburetor system, piston and valve modifications, and the age of the engine.