Don,
Go to the beach, pick up a grain of sand...then realize how much you
have diminished the beach...same analogy...everything that you have
described will not make one bit of difference in the performance of your
car! It's fun to think about, but it just won't matter...further more if
you go to the shop and ask them about this...you will become a
mark!...they will have great fun extracting dollars from your wallet for
absolutely nothing.
Jim Swarthout
-----Original Message-----
Subject: 30 degree valve seats and 3 angle valve grid
David Vizard and others on these lists recommend 30 degree valve seats
rather than 45 degree valve seats because they improve flow at low valve
lift. Rimflow and/or back cutting the valves also help during low lift.
On page 207 of David Vizards "Tuning the A series Engine", he points out
that a single angle 30 degree valve seat reduces the port diameter as
compared to that of a single angle 45 degree seat. So while the single
angle 30 degree valve seat increases flow at low lift, the resulting
narrower port reduces flow at high lift. He then points out that a 15
degree sharp angle has the same flow characteristics as a smooth radius
bend. He then adds multiple 15 degree angles to the 30 degree valve seat
such that the port diameter approximates that of a single angle 45
degree valve seat.
Is this what a "3 angle valve grind" is, or is it something else???
Thanks,
Don Malling
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