Re Ground Cams

[Dan Ingram 1]

Excuse me if I seem a bit thick but I think I'm missing something. How can regrinding a cam increase performance? Surely you can only take material off which I thought would reduce performance as there is less lift and duration which is what I thought increased performance?

 

I'm sure theres a very simple answer but I'm obviously missing it.

[Doof 11]

Remember that if you grind the cam at its lowest point, the difference between that and its peak increases....you can then use larger shims, or in the case of Mi16's hydraulic shims to take up that gap and hence you have more lift.

 

Thats how i see it anyway, correct me if i'm wrong.

[welshpug 1,627]

you remove material from the opposite side to the lump, hence there is more difference in the curve.

 

(on a mechanical bucket you adjust the shims accordingly, on a hydraulic bucket they adjust automatically)

[Dan Ingram 1]

Ah I see, yes that makes sense. Thought I was missing something, Thanks

[Baz 421]

Plus you move the base point/axis, adding to the peak point of the lobes.

Edited February 22, 2008 by BazGTMi

[Beastie 1]

If the lift was the only thing to consider then that would be the end of the story. However it isn't: Other important factors of cam design are rate of opening, as defined by the acceleration ramp, quietness largely influenced by the clearance ramp and timing. There is a limit to how much can be done with a re ground cam - if you wish to deviate from standard timing then sometimes it's possible to achieve a realistic compromise with a reground item. In some very important ways you aren't missing anything, Dan - I try to avoid them wherever possible and fit new items instead.

[Dan Ingram 1]

I'm not intending to get any, just wondering how it works thats all. Got to feed my inquisitive brain