Determining top dead center

There are a multitude of different dampers and three different timing pointer locations on a Chevy. I don't know about other brands. Chevies use 12:00 noon, 2:00 O'Clock and 2:30 O'Clock and if anyone has had the motor apart, you don't know if they used the original damper and timing pointer or other swap meet parts when they went back together with the motor. The whole reason for doing this operation in the first place is to be able to time the motor with a timing light and know, absolutely, that the timing is correct. The elastomeric material that connects the outer ring of the harmonic damper to the inner hub which presses onto the snout of the crankshaft begins to break down over a long time due to ozone in the atmosphere and oil and fuel which may find its way onto the material. When this happens, the outer ring may slip in relation to the inner hub, rendering any attempt to time the motor with a timing light futile. Even though this operation you are about to do will bring the timing marks back to correct for the time being, there is no guarantee that the ring will not slip further after a while. If you want to bulletproof the operation, then start with a new or rebuilt damper and use the correct timing pointer for that damper.  

There are a multitude of different dampers and three different timing pointer locations on a Chevy. I don't know about other brands. Chevies use 12:00 noon, 2:00 O'Clock and 2:30 O'Clock and if anyone has had the motor apart, you don't know if they used the original damper and timing pointer or other swap meet parts when they went back together with the motor. The whole reason for doing this operation in the first place is to be able to time the motor with a timing light and know, absolutely, that the timing is correct. The elastomeric material that connects the outer ring of the harmonic damper to the inner hub which presses onto the snout of the crankshaft begins to break down over a long time due to ozone in the atmosphere and oil and fuel which may find its way onto the material. When this happens, the outer ring may slip in relation to the inner hub, rendering any attempt to time the motor with a timing light futile. Even though this operation you are about to do will bring the timing marks back to correct for the time being, there is no guarantee that the ring will not slip further after a while. If you want to bulletproof the operation, then start with a new or rebuilt damper and use the correct timing pointer for that damper.  

Before starting this operation, measure the outside diameter of the damper and buy a timing tape which matches the diameter of the damper. Also buy a piston stop tool. Purchasing a tool that has a hole drilled through the center of the probe will allow pressure or vacuum to escape through the hole with the piston moving up and down in the bore with the rocker arms disabled (valves on their seats) and will make the job easier.  

Before starting this operation, measure the outside diameter of the damper and buy a timing tape which matches the diameter of the damper. Also buy a piston stop tool. Purchasing a tool that has a hole drilled through the center of the probe will allow pressure or vacuum to escape through the hole with the piston moving up and down in the bore with the rocker arms disabled (valves on their seats) and will make the job easier.  

http://store.summitracing.com/egnsearch.asp?Ntk=KeywordSearch&DDS=1&searchinresults=false&y=5&N=+115&Ntt=timing+tape&x=22

http://store.summitracing.com/egnsearch.asp?Ntk=KeywordSearch&DDS=1&searchinresults=false&y=5&N=+115&Ntt=timing+tape&x=22