You'll get better bottom end torque out of a standard cam, and running high compression than you will out of any persformance cam... but, you wouldn't have bothered going to 1380 if all you wanted was a motor that starts to run out of puff before 5000rpm
a cam similar to what the doc is suggesting with low duration and low lift will still give reasonable torque down low and more poke every where else. I've found that even with low duration cams, if the lift is too high you will still see a drop in bottom end torque.
I agree with the doc that from a performance point of veiw, a fast accelerating flank and large nose radius are desireable (:lol: just remember that as your flank acceleration rate increases, your tappet clearance also needs to increase so make sure you refer to the cam grinder for new clearances)...... As for pointy cams wearing out quicker, if the cam
rubbed over the follower instead of turning it, yes it would wear out quicker.. but the 2 surfaces don't rub. Also if there
wasn't a continous radius in the face of the lobe, then yes, it would try and bang its nose off as it passes over the follower, but there is a continuous radius.. which means that the lobe only makes contact on the same tiny tangent point regardless of where the valve is closed, opening, fully opened or on the way down...
Lubricants aside for a moment, the only friction created (provided the cam has been ground correctly to begin with) is as a result of the valve springs transfering pressure back down the valve train to the face of the lobe. Thats in a static situation. Once its in motion, whats happening to the lobe, is the surface of the lobe is being pulled as it turns the follower. As the load on the lobe increases (ie as the valve is opened more) the tension on the surface of the lobe increases....... If anything, a larger nose radius increases the period of time that the lobe surface is exposed to peak tension... there is more friction borne on the lobe surface with large nose radius cams per cycle as a result.
There is one local company (that the doc and I have both had experience with) that I have recently found do not heat treat their cams properly.... This would have a dramatic effect on how long the cam lasts... I have also had experience with one UK company that don't temper their cams properly, and as a result you can phyiscally see stress cracks in the surface from where it has been quenched... at least its hard I guess, but this still isn't a good look.
The "pointy profiled" VP3 that you wore out in 50,000 Km, came from the local company that I have since found no sweet FA about metallurgy, or the importance even chosing the right steels for turning up billets for cams. I dare say that the "Pointy" cam you had that wore out so quickly, wore out because it either wasn't ground properly or heat treated properly.
