Quote:
Originally Posted by charlie66
You're saying my cam is aggressive, do I have to worry about breaking a lifter bore with this cam?
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The possiblity of a lifter bore breaking is not an issue from the cam itself. If something goes wrong on a lifter that is when there is a risk of breaking a lifter bore.
For your cam the average duration it takes the tappet to go form .006” tappet lift to .050” tappet lift is 51*. The smaller that number, the more acceleration and the quicker the lifter starts to move. This is fine, but the lifter has to have a sharp enough bleed rate or it will tick or make extra sowing machine noise. This cam must have the plunger of the lifter bore lockup up by .005” tappet.
This cam is pretty aggressive because the plunger on the lifter does not have much time to recover for the next cycle before it need to open the valve again... The lift isn’t aggessive at all, but the intensity is. A less aggressive cam like a Comp Extreme energy marine HR with 55* of average intensity the lifter has to lock up by .009” tappet to operate quietly, giving the lifter plunger more time to recover and lock up for then next cycle. That is a big difference.
If the lifter can’t lock up the plunger by those points, it has the same effect of running a Mechanical cam with excessive lash. It increase the acceration on the valve terrain and is hard on stuff.