What is a camshaft timing?
A Basic Overview of Cam Timing Advancing or retarding the cam pushes the centerline of the camshaft to one side or the other of the crankshaft centerline. This changes the Timing of the valve opening and closing events, in relation to the position of the piston in the cylinder.
How is the timing of the cams set?
Cam timing is what determines when the valves open and close with respect to the position of the pistons in their bores. It is set when the engine is built- by placing the camshaft and crankshaft in the correct relationship. It cannot be adjusted on a stock engine.
How does cam timing and Cam separation affect the engine?
The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed.
What’s the best way to fix cam timing?
Fit the cam gear retaining nut and pinch up tight. Fit the crank pulley and retaining bolt you’re going to use and tighten the bolt up. Position piston one half-way down the bore. Fix the stop plate across the bore, securing with 3/8″UNC bolts into the stud holes, stop bolt head over the piston centre.
How does advancing or retarding a camshaft work?
Advancing or retarding the cam pushes the centerline of the camshaft to one side or the other of the crankshaft centerline. This changes the Timing of the valve opening and closing events, in relation to the position of the piston in the cylinder. How is it measured? Find the lobe centerline in relation to the piston’s position in the cylinder.
The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed.
What’s the best way to set the cam timing?
Rotate crank until the rockers on cylinder one are holding both valves open a little. This is the overlap period and how you are going to set the cam timing. Look at the pointer and pulley. Rotate crank to set them so they are directly opposite each other.
When does the exhaust valve open on a cam?
Since the camshaft turns at half of the speed of the crank, the power stroke only sees one fourth of a turn of the cam, or 90 camshaft degrees. As we move closer to the bottom of the cylinder, a little before the piston reaches the bottom, the exhaust valve begins to open.
What should the cam timing be on a DOHC engine?
If the cam timing was set to this smaller/narrower 110.5 degree lobe separation angle, the engine would behave much differently than the 113.5 degree lobe separation angle.