How do you check and replace lifters/tappets in an LS1?
 

I was wondering how you'd check for a collapsed lifter in an LS1, and if you had one, how do you replace them?

Can they be replaced with the motor in the car, just by removing the heads and pushrods?

On a related subject... supposing one were to wish to bolt on new heads, which have a thicker deck than stock... how do you know what length pushrods you'll need, for the new heads?

Yes you access the lifters by pulling the heads. As for the pushrods you can get an adjustable pushrod that you use to determine what length to order.

:iagree:

This is basically what you'll see with the heads removed (just not this clean and lacking the notches in the pistons):

http://my.execpc.com/~thimbel/headswap/DSC01744.jpg

Note the two plastic trays with a single screw in the center fastening them to the block. These contain the lifters and keep them oriented to the cam lobes (keeps them from spinning).

Remove the trays, and most likely, the lifters will come out with them. In this pic, the trays (and lifters) are out and sitting on top of the engine.

http://my.execpc.com/~thimbel/headswap/DSC01710.jpg


The deck thickness of the heads can be irrelevant to pushrod length, but there are a lot of other variables involved too, so if changing heads and/or cam, it's always best to measure for correct pushrod length for your desired lifter preload. (this dimension can vary depending on lifters used too).
Comp Cams makes an adjustable pushrod for the purpose of measuring. It's like a $20 item. I have one if you would ever want to borrow it, just shoot me a PM.


:cheers:

Hokay... this may be something I work on this winter. Thinking about buying new heads, and as long as I'm in there... everything else too. :)