Re: the valve piston clearance measurement: I believe I've been told that
you want over .100" clearance to avoid interference at high revs.
And yes, high lift rockers often cause coil bind problems.
Myles
----- Original Message -----
From "David Riker" <davriker at pacbell.net>
To: "Jon Paschke" <JPASCHKE@bak.rr.com>; <spridgets@autox.team.net>
Sent: Tuesday, November 26, 2002 10:55 PM
Subject: Re: head bolts
> Jon
> Experienced mechanics have told me that it is OK to change the rocker arms
> without loosening the unaffected nuts and without replacing the head
gasket.
>
> However, you may not want to do that for a very different reason. Once
you
> combine a cam with high lift, overlap, AND a set of high lift rockers, you
> may run into a clearance problem with the top of the piston. With this
> combo you are supposed to remove the head, place some clay on the top of
one
> of the pistons, replace the head, adjust the rockers, and then rotate the
> engine by hand one revolution. Remove the head again and observe the
> imprints in the clay. if it is less than 15 thousands thick, the valves
> will hit the pistons. This may not be a problem on spridgets, but I know
> that is the procedure for V-8's.
>
> Also, the above combinations of cam & rockers can result in valve spring
> bind. Again, just make sure that there is still some clearance when the
cam
> is at full lift.
> David Riker
> 63 Falcon
> 70 Torino
> 74 Midget
> http://home.pacbell.net/davriker/
>
> ----- Original Message -----
> From: "Jon Paschke" <JPASCHKE@bak.rr.com>
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