<div dir="ltr"><div class="gmail_default" style="font-family:garamond,serif;font-size:large">I don't have definite engineering knowledge but I suspect there is more than one reason for this.  Increasing the mass of the valve head near the transition to the stem may have to do with heat transfer and resistance to distortion, but I suspect the exiting flow of exhaust gas may determine the shape as well.  </div><div class="gmail_default" style="font-family:garamond,serif;font-size:large"><br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">You could reduce the overall mass by using smaller-diameter stems.</div><div class="gmail_default" style="font-family:garamond,serif;font-size:large"><br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">Duncan</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Oct 6, 2020 at 7:52 AM Phil Gott via Fot <<a href="mailto:fot@autox.team.net">fot@autox.team.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Does anyone know why the 5/16 stem exhaust valve flares out in a cone shape to the valve head instead of maintaining the stem diameter diameter all the way to the head? I am thinking that there could be a gain if we can find a valve of correct dimensions without that flare.<br>
Phil Gott<br>
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Sent from my iPhone<br>
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