wht90lx

The E cam is listed as an emmissions legal cam shaft but will 1.7 RR change that? And is there any real PTV clearance issues with this setup and some GT40P heads?

aode08

why worry about emmisions,?

wtih the mods you have and that cam you might not pass, or you might, long as your running cats.

add 1.7's and youll push the power in the upper rpms a little, so it might not be in your favor to do so.

OnyxCobra

I don't think it'll change emissions, all it changes is lift. Emissions i'd think would come from duration and overlap of the cam, neither of which the larger rockers will change. I thought duration effected cam operating RPM also but I'm no expert. I think that kind of lift will be pushing it with stock pistons but you should clay the piston to find out for sure, also, either way you're going to need stronger valve springs.

Joel5.0

Theoretically......nope. Lift is not an issue with PtV problems, if you look into the cam events @.050" tappet lift, and assuming it was installed per the spec card, both valves will be open .080" with a 1.6 rocker or .085" with a 1.7 rocker when the piston is at TDC during the overlap cycle (changeover from exhaust to intake cycles, exhaust closing and intake opening), factor in the head gasket thickness (~.045") and now you have a distance of .035" and .040" that piston should be away from the valves. The valves are inside the chamber, below the head's gasket surface ~.085", so now you have a + .050" or .045" clearance...... add the valve relieves + dish on the piston crown, the fact that the pistons are usually under the block's deck >.005", and the clearance should be above .100" with either rocker on both valves. Do suggest to do the check with clay though, specially if you don't degree the cam...... Checking Piston to Valve Clearance

wht90lx

my county requires them