EllowViper
Enthusiast
Installing my TD's and wanted to check my initial valve train geometry just to see where my roller tips were in relationship to my valve stems. See the link below as a quick reference to what I'm seeking:
Google Image Result for http://www.pontiacpower.com/pics/rockerarm2.jpg
OK, TD comes with a little tool to check basically the same thing I was seeking but you have to have the spring off the valve. Seemed a bit unecessary so I figured all I needed to do was figure out how to "see" where the roller tip was hitting the valve. Here is how I did it.
Basic valve with TD rails installed.
Simple piece of thin masking tape over one valve (intake)
Take a rocker and place into position
Let the rocker fall on the top of the valve a few times to indent the tape where contact is being made
Remove the rocker and look for the slight line/indentation where the roller tip is hitting the valve
You can take a pencil or fine marker and trace over the indentation
Now that I know where my initial valve train geometry is, I can get my handy dandy push rod length checker out and install a rocker with the recommeded pre-load/lash; cycle the engine a few times, remove the rocker, and look at the full contact patch of the roller tip on the top of the valve. The tape should be compressed just where the roller tip is making contact with the valve. No more guesswork. I guess its the same basic theory as using plastigauge to check rod/main bearing clearances via a squash measurement.
Google Image Result for http://www.pontiacpower.com/pics/rockerarm2.jpg
OK, TD comes with a little tool to check basically the same thing I was seeking but you have to have the spring off the valve. Seemed a bit unecessary so I figured all I needed to do was figure out how to "see" where the roller tip was hitting the valve. Here is how I did it.
Basic valve with TD rails installed.
Simple piece of thin masking tape over one valve (intake)
Take a rocker and place into position
Let the rocker fall on the top of the valve a few times to indent the tape where contact is being made
Remove the rocker and look for the slight line/indentation where the roller tip is hitting the valve
You can take a pencil or fine marker and trace over the indentation
Now that I know where my initial valve train geometry is, I can get my handy dandy push rod length checker out and install a rocker with the recommeded pre-load/lash; cycle the engine a few times, remove the rocker, and look at the full contact patch of the roller tip on the top of the valve. The tape should be compressed just where the roller tip is making contact with the valve. No more guesswork. I guess its the same basic theory as using plastigauge to check rod/main bearing clearances via a squash measurement.
