The following instructions begin after the timing cover and old timing set have been removed.
Installing the timing set and degreeing the camshaft will be easier if you loosen the rocker arms so that the camshaft can turn freely. You should be able to turn the camshaft by hand. Make sure that the engine mounting surfaces and your new timing set have been thoroughly cleaned with a good solvent. If you are using a timing set with three keyways, select the appropriate keyway for your camshaft timing specifications. COMP Cams ® recommends the standard timing position for most applications. This position uses the round or “O” timing and keyway marks. Standard Timing Location: This is the same as original O.E.M. setting. Use keyway and crankshaft gear tooth marked “O”.

4 Degree Advance: Use keyway and crankshaft tooth marked . Note: The or advanced position should not be used without degreeing the camshaft. Many camshafts have the proper advance built in. Advancing the cam will reduce intake valve to piston clearance and increase exhaust piston to valve clearance.
4 Degree Retard: Use keyway and crankshaft gear tooth marked . Note: The or retarded position should not be used without degreeing the camshaft. Many cams have the proper advance built in. Retarding the cam will reduce exhaust valve to piston clearance and increase intake piston to valve clearance.
Step 1 – Lower Gear Installation Select the appropriate keyway for your camshaft timing specifications. COMP Cams® recommends the zero timing position, which uses the round timing mark and round keyway mark. If the camshaft needs to be advanced or retarded, use degree bushings (Part #4760) as they are a more accurate method of positioning the camshaft. Using your lower timing gear installation tool (Part #4920), install the lower gear on the crankshaft making sure that the gear is fully seated against the crankshaft flange and the timing marks on the gear are toward you. (Never strike the gear with a hammer, chisel, or punch).

Step 2 – Chain Installation Now that the lower crankshaft gear is installed rotate the crankshaft using your crankshaft socket, (Part #4793 for Small Block Chevy or #4797 for Big Block Chevy), until the appropriate crankshaft gear tooth is in the 12:00 position and the crankshaft gear keyway slot is in the 2:00 position. The #1 piston should be at top dead center. Rotate the camshaft until the camshaft dowel pin is at the 3:00 position. Loop the chain over the camshaft gear. Align the camshaft and crankshaft timing marks and loop the chain around the crankshaft gear. Lift the camshaft gear into place on the camshaft. Install the three camshaft bolts (finger tight for now). Make sure that the camshaft gear timing mark aligns with the proper crankshaft gear timing mark. The camshaft timing mark should be at 6:00 and the crankshaft gear timing mark should be at 12:00. If this procedure is missed by even one tooth, engine damage can result.
If a mechanical roller or retro-fit hydraulic roller cam is being installed, a cam button (Part #200 or #202 for Small Block Chevy, #205 or #207 for Big Block Chevy) must be used. Install the cam button per the supplied instructions. A cam button is not required on 87-present models equipped with factory roller camshafts using stock camshaft retainer. If you are using a cam lock plate (Part #4605), install it with the bolts leaving them finger tight. Do not bend the tabs at this time.

source

Related Tags: accurate method, camshaft, camshaft timing, camshafts, chain tools, Chevrolet, crankshaft, exhaust valve, flange, gear tooth, installation tool, intake valve, keyway, kit components, piston, rocker arms, solvent, surfaces, timing chain, valve clearance