mvvette97

iTrader: (18)

Is it the XR or the XER that is known to cause valvetrane noise and damage?

prplhaz

I don't know about "valvetrain damage", and noise is the nature of the beast which can be minimized with proper pushrod length and valvetrain setup.....BUT Comps' XER line has the more radical valve opening and closing rates and would be considered "harder" on the springs.

mvvette97

iTrader: (18)

so is the XR a little more mild as far as the opening and closing?

prplhaz

Yep, that's correct.

GuitsBoy

iTrader: (4)

I think youre referring to XE lobes (not XR). Yes those are more gentle on your valvetrain. The XE-R lobes are more agressive, but tehyre definately worth it. You can still get good springlife out of a set of dual springs and an XE-R cam.

PREDATOR-Z

XE ramp rate variance 53
XE-R ramp rate variance 49
LSK ................ >>> 50
Cammotion (futral) >>>>50

mvvette97

iTrader: (18)

it says this for the cam...Competition Cams Comp XR281HR 228/230 571/573 112 Part number 54-428-11

stevewix

go 54-446-11, i have it in my car and it's a bit lumpier than i'd like but a very preliminary tune yielded 413hp with simply a cam & headers