It'll be fine, there are loads of cam 'sets' with different inlet and exhaust cam specs, the head flows are different for inlet and exhaust ports also (see flow figs on CNC Heads website) - dont forget the only thing to push air into an engine is atmospheric pressure whereas getting air (exhaust gases) out of an engine is driven by flywheel momentum - so inlet needs more
help usually, rule of thumb, but this does depend on specific engine setup.
One of the problems with cams is comparing like with like, all manufacturers measure and describe them differently, maximum lift is usually fairly comparable but depends on where zero is taken from, before ramp angles ? after ? at 0.1mm lift ? all are different. Likewise duration, the time the valve is lifted, somepeople describe this at 0.1mm lift, some at 20 thou, etc etc - duration at 0.5mm lift is far less than at 0.1mm lift but the actual difference in valve actuation, and therefore gas flow, depends on the shape of the lobe itself.
A guy on CGTI forum, H8SV8S, had some cams measured properly a year or so back:
ABF cams:
inlet=219degrees at 1mm lift, 10.8mm max
exhaust=220 degrees, 10.8mm max
KR cams (1.8 16V golf GTI)
inlet=218 degrees, 9.6mm max
exhaust 226 degrees, 10.21mm max
so as you see. VW's own cams are different specs and the ABF ones are actually pretty fruity.
Schrick 268 inlet:
11.5mm max lift and 268degrees duration but unknown from catologue what lift this is at only that it doesnot include ramps which are maybe 0.1-0.2mm
so its impossible to compare them....you have to go on what people have done and I have to say that given the stock abf cams are as fruity as they are, I'm no at all suprised that it makes a good pair to a schrick 268 inlet cam. My suprise is that this combo works with reprogrammed stock management and that a pair of 268's doesnot - must be something to do with lambda control as the maf on the abf would seem to be ok with a 268
cheers
rob
