Shuffle them around and see if you can get them uniformly closer. Then
regrind them in their new seats and see if they will get within spec or less
than spec and need a little grinding to make them perfect as the exhausts
do. When I did the head on my L-1 Salonnette ten or so years ago, I found
that it was necessary to try to mate the valves to the rockers by setting
the rockers to their optimum position for correct valve timing and then
grinding the valve stems to obtain the correct clearance. So #1 valve
didn't necessarily go back into #1 slot when the head was redone. I seem to
recall that there is some discussion of this in Phillip H. Smith's "Tuning
and Maintenance of M.G. Cars." If your intakes are of varying lengths and
"too short" then this has been done at least once before in their lives and
they may need replacing, not because they are worn, but because they don't
have enough meat left on the stem to match up anymore!
- Mike Hughes -t?t-
> Hi All,
> I've worked on a lot of different MGs and restored quite a few, but this
PA
> is by far the hardest! Here is the problem.
>
> The head was cleaned, cracked tested and new seats and guides installed.
New
> exhaust valves were purchased as the intake valves were deemed as good.
The
> shafts of the intake valves are various lengths within a few thousands of
each
> other.
> The exhaust valve shafts are all the same length as they are new. I
assembled
> the cam shaft, rocker shafts and rockers (exactly in the same order they
came
> off). The rocker bushings are set to they beginning position as directed
in
> the manual.
>
> All of the intake valves are long (.006 clearance to the cam) by a few
> thousands. OK, fine they can be ground. The exhaust valves are short. #1
cylinder by
> .070, #2 cylinder by .045, #3 cylinder by .20 and the #4 cylinder by .012.
>
> The machine shop is trying to tell me that the rockers are worn that much
and
> that different. I sure cannot see that big a difference comparing #1 to #4
> rockers. Anybody got a clue as to what else to look for? Anybody got a
drawing
> of a rocker?
>
> Confused and frustrated
> Dennis
> PA1518
>
> /// unsubscribe/change address requests to majordomo@autox.team.net or
try
> /// http://www.team.net/cgi-bin/majorcool
> /// http://www.team.net/mailman/listinfo
> /// Archives at http://www.team.net/archive/mg-mmm
> /// Send list postings to mg-mmm@autox.team.net
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/cgi-bin/majorcool
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/mg-mmm
/// Send list postings to mg-mmm@autox.team.net
|