Are you using stock pushrods?
Since the rocker pedestal bolts directly to the head,
milling the head or block does not directly affect the
geometry of the rocker arm tips with respect to the
valve stem tips (ie, their relative positions are
unchanged). But it does alter the relative positions
of the adjustable ends of the rocker arms and the
lifters, ie the distance is reduced by the amount
removed. Since the length of stock pushrods is fixed,
this can be a concern.
Now .030 is probably not enough to make a difference,
the ball end adjustment screws on the rocker arm tips
can compensate for that samll amount.
But if you remove a lot, .100 or more, you should at
least check that there is enough adjustment, and also
that the parts do not bind at full lift.
The alloy pushrods allowed easy shortening, just pop
off one of the steel tips, remove the needed amount,
then tap the tip back in.
Not sure if anyone is selling those now, but I've seen
steel tube pushrods.
The comp manual mentioned putting spacers under the
rocker pedestal, to change the rocker/stem geometry
for high lift cams. Though I've done this on my
motors, I'm not sure how important it was, as we still
had lots of wear of the rocker tips and valve stems.
Hope this helps.
Carter Shore
--- Craig Smith <CraigS@iewc.com> wrote:
>
> I got a question along this...
>
> I had the head on my 71 shaved .030, I got to
> thinking about the rocker
> angle to the push rods.
> I lowered the deck of the head but I didn't do
> anything to the rods, do I
> need to shim the rocker pedestals up to make up the
> diff ?
Get email at your own domain with Yahoo! Mail.
http://personal.mail.yahoo.com/
|