Right. If only the timing is changed you don't need to mess with
anything else.
On these longer cams that get you the power you need, the lift is also
changed to something like .425". If the lift isn't much higher than BJ8
you don't need to cut the block. You can check your clearance on
assembly and see if you need to do that.
I had a MkI cam ground to 280 with .425" and have not yet run it. My
head has been planed so I may need to cut the block after I measure it
to see about my clearance. Clay is put in the chamber and the engine
turned over. Measure the clay and viola.
Rick
San Diego
On Jan 17, 2005, at 7:18 PM, Greg Wilkinson wrote:
> Hi Steve,
> Something is definitely missing in that equation. If only the
> duration is
> increased, why would you need to port the block? Same holds for the
> stronger
> springs. If the lift is the same over a longer duration, the valves
> would
> probably open and close slower than stock for a given RPM. Sure it's
> not
> necessary to put headers on, but I don't think a cast exhaust manifold
> can
> breath as well. Isky reground my BJ8 cam to a slightly longer duration
> and
> higher lift, the base circle of the lobe is almost flush with the
> shaft now.
>
> Best,
> Greg
>
> -----Original Message-----
>
> Hiall,
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