5.7 vortec rebuild ?? will non vortec heads work ?

[Tom]

Originally Posted by garyd1961

The old 350 cam had like 396/401 lift and the L31 cam has 414/428 lift plus it's a roller which opens the valves faster than the old flat tappet cam.

Yes the cam has more lift for a given duration, that's a product of the fast ramps you referred to that open the valves so quickly. The ramps can be steeper due to the roller so more lift for a given duration. That aside, lift doesn't really affect the engines operating range, duration does. And in that area the vortec oem cam is still absurdly tiny.

As for the pistons, yes I get domed pistons don't propagate the flame front as efficiantly as a flat top or dished piston, but at a 9:1 ratio or so it won't be too big a deal. Besides, after seeing inside some European engines lately like the 5.0 from jag/land rover or the 3.0 from Audi, Im really starting to wonder how much faith to put into flame fronts and all that jazz.

[garyd1961]

Iui

Originally Posted by Tom

Yes the cam has more lift for a given duration, that's a product of the fast ramps you referred to that open the valves so quickly. The ramps can be steeper due to the roller so more lift for a given duration. That aside, lift doesn't really affect the engines operating range, duration does. And in that area the vortec oem cam is still absurdly tiny.

As for the pistons, yes I get domed pistons don't propagate the flame front as efficiantly as a flat top or dished piston, but at a 9:1 ratio or so it won't be too big a deal. Besides, after seeing inside some European engines lately like the 5.0 from jag/land rover or the 3.0 from Audi, Im really starting to wonder how much faith to put into flame fronts and all that jazz.

The vortec cam may be absurdly tiny but I smoked a 5.3 Silverado with mine saturday.
The L31 cam makes a lot of torque.