1. Remove the spark plugs to relieve compression in the cylinders.
2. Insert a long thin object (like a screwdriver or spark plug electrode) into the spark plug hole of the cylinder you're checking.
3. Slowly rotate the engine by hand using a wrench on the crankshaft bolt; turn it in its normal direction.
4. As you rotate the engine, watch the object in the spark plug hole. When the object first starts moving down, the piston is going up and that is the beginning of the compression stroke.
Finding the Correct Timing Mark for a 1970 350 Truck Motor:
The correct timing mark for your engine will depend on the distributor you're using, so it's always a good idea to consult your vehicle's service manual or distributor specifications for the exact information. Here are some general steps you can follow:
1. Locate the timing marks on the engine and the crankshaft pulley or harmonic balancer.
2. Clean the marks thoroughly to improve visibility.
3. Use a timing light or TDC indicator to check the alignment of the marks.
4. The specific mark you need to align with will depend on your engine and ignition timing specifications. For example, it might be "0" or "TDC" for Top Dead Center.
5. Adjust the distributor cap or rotor (depending on your distributor type) to align the correct mark, following the specific instructions for your engine and distributor.
It's important to check your engine's specifications to ensure you have the correct timing for optimal performance and to prevent engine damage. If you're unsure about any of these steps or your ability to perform the task safely and accurately, it's best to consult with a qualified mechanic or refer to your service manual for professional guidance.
