Looking for information on which cams have enough overlap in valve timing so that the EGR valve becomes redundant and is not needed. Such as the '96 LT4 motors in the Vette which did not need an EGR valve to pass strict emmissions tests.

And will work very well in a TPI motor of course...

 

Not saying your wrong, but I have never heard of such a thing and I am basically aiding you in a TTT cause I wanna know the answer to this as well. Not only which cam would have enough of this overlap you speak of, but also, how and why this works.

 

Yes, this is possible as all LT4 motors do not have an EGR valve. This is possible because the exhaust valve is not completely closed when the intake opens and the piston begins traveling downward, sucking in both fresh air/fuel mixture and the spent exhaust gases from the slightly open exhaust valve.
This creates an internal EGR like valve, so the EGR is redundant and is eliminated in the LT4 motors.
Here's a few links detailing the difference in the LT1 and LT4, EGR eliminated is one mentioned.
http://www.malcams.com/legacy/misc/LT4.htm
And look down at #6 on this page:
http://www.geocities.com/MotorCity/S...5/camaro1.html

So, anybody know what the min/max lope separation is so that the EGR can be eliminated and still pass emissions?
Would like to use Vortec heads and don't want to have to weld on my headers and make an external EGR.