I installed and degreed my son's CC XS268S cam last week and wasn't to happy with how it measured. How accurate should the lift and duration figures be compared to the specs provided? It was short on lift and duration on the intake side and high on lift on the exhaust. I checked it three times with the exact readings all three times. I was tempted to check the other cylinders and compare to what we measured on cylinder 1 but just figured I'd be more pissed off if the others were all out of whack or worse. Hope this thing lives through the breakthrough-sure feels rough texturewise. Bob

It would take an old fart like me to remember this but Comp used to provide what was known as " The Green Card " with all thier race cams.It was a little green card that had listed on it what the lobe was suspose to measure and what it did measure as measured by Comp Cams...... Back then it was not uncommon to be a couple thou off in lift as a couple deg off in various durations..... It's been several years since they stopped supplying this card.

How one measures a cam can make a big difference in what they measure.Simple things like how you even look at the dial indicator or the accuracy of the degree wheel and even how you mark the degree wheel.... is the dial indicator a degree or two off from paralell or tilted in some small way ... all these small inaccuracies can by them selves add up and make a good lobe appear to be wrong.If doing it in a block it's even harder with built in errors just in the block.

That said I would have to say this ...and this is just my opinion but of the various cams I have used or helpped with other peoples projects ... Crane was probably the most consistant in specs of the big brand names that I have expirence with.

If its wrong, why did you even bother continuing with the installation :confused: How are these guys supposed to find out about defects if we just put up with them instead of sending the stuff back ???? If it's not right, send it back and get one that is ... otherwise, don't complain about it.
Just my opinion,

If its wrong, why did you even bother continuing with the installation How are these guys supposed to find out about defects if we just put up with them instead of sending the stuff back ???? If it's not right, send it back and get one that is ... otherwise, don't complain about it. Truth is the difference measured probably won't add up to a performance difference that will be measureable by me if the rest of the lobes are the same, so I'll check some more lobes and see what the rest of the cam is like. But Comp isn't a new or small company, they should be on top of quality control IMO.

We check every cam with the "Cam Doctor" before we install it and find that 1 degree off on duration, .5 degrees off on lobe separation and .02" off on lobe lift is not uncommon.

My Comp 296AH-8 cam had 3º more duration between .050 and .006" on the closing side of the intake lobe then speced.

and .02" off on lobe lift is not uncommon.
Good grief. 0.020" lobe lift error? That's 0.030" at the valve. 30 thou? That could be 5-6% . Tell me what company to stay away from.

Originally posted by 70GS455:
Good grief. 0.020" lobe lift error? That's 0.030" at the valve. 30 thou? That could be 5-6% . Tell me what company to stay away from. Thanks for catching my error. It should have been 0.002" lobe lift. FWIW, most of the cams we have checked are off between 0.0005" and 0.0025". I don't have records of any cam that was off more than 0.003".

Ok, that's not too bad. I would be happy with only a couple thou.