I'm putting a new cam in my car and I was wondering something.
I have the #1 piston at TDC on the compression stroke. But how do I know that it is perfectly at TDC I know the hub has an arrow on it but anyone could put it on just off of 12 o'clock because it's not keyed, I guess what i'm asking is does it really mater if it's not perfectly at TDC, the car is a 1995 with the opti having the extra little cutout thing on the back so you can't put it on wrong.

 

You should use a piston stop in conjunction with a degree wheel to determine TDC.

 

You don't need to be at TDC #1 or TDC for any piston to put a cam in a LT1. The cam gear just needs to be in the right relation to the crank gear. Line the dots up (TDC #6 btw) and put the cam in. Its a pretty none adjustable setup. The whole TDC thing is only used to check your cam grind with the machine card and to advance or retard your cam from something called centerline. We don't usually do this step and rely on the cam manufactures quality and the fact that we are just street/strip cars not full dragsters. Advancing/retarding the cam is for tweaking sort or speak. Many cam companies grind in 4 degree or so of advance to pretty much all there over the counter cams because the average guy tends to over cam his car. The advance adds low end response with a sacriface up top. Advance makes the car "feel" faster.

Jeff D

 

When you put "LT1" in the topic, its a pretty good chance it should have been posted on "LT1 Tech"...... moving

 

Your right, the hub is not keyed but the crank gear is. Timing gear alignment is all you need to worry about. The LT1 is INTERNALLY balanced, it doesnt matter how you put the hub on, the mark on the hub is for reference only. Get it as close as you can for future reference and that will be good enough.