Anyone know what the maximum valve lift is before you hafta worry about hitting the pistons? My motor isn't together yet for me to check, and I was just curious if anyone knew. . .

 

LT4 heads 2.00 valves stock pistons, etc. . .

If theres a formula for this how do i go about finding it or can you tell me?

 

Hey Rob, remember that you have to take these into account:

cam lift
possibly the lifters...don't know if they come in different heights
pushrod length
rocker arm ratio
length of valve stem
size of valves
whether or not the pistons have relief cuts in them...how deep they are cut and the shape of the relief...etc
head gaskets

Any variation of the above from stock will change the piston/valve clearance. I want to say that I remember hearing the maximum you could go would be around 0.650", but don't quote me on that.

On another note...is that thing coming off of the jackstands any time soon?

 

I e-mailed Craig at GTP racing, they built a LT1 with the bottom end remaining stock and the cam they installed was 235/242, 568/592, 112 with no clearence issues on factory pistons. Hope this helps.

 

With the use of mostly stock parts, you can usaully be safe not going over .600 lift.

 

none of that matters. . . except for valves opening .600" is a valve opening .600" no more no less. . .

Is that final lift after 1.5 or 1.6?

 

3.48" minimum on a stock shortblock


Piston to valve is a function of lift vs. duration. Most guys dont check with common combinations... cc306's, gm847's etc.

IMO, always check, it doesnt take long to do things right, but it'll take forever the time you do it wrong

 

You're right, Rob...I thought about it some more after I posted that and then realized that I'm a retard. My brain doesn't work too well on Fridays.

 

wasn't trying to make you feel retarded jeff