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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>That is one thing to consider.<o:p></o:p></p><p class=MsoNormal>When is turbulence supporting and when is turbulence overdone and disturbing.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I could imagine to force too much turbulence with a very small squish gap the flame front expansion is compromised, thus slows down, and lowers the hp output.<o:p></o:p></p><p class=MsoNormal>That’s why we had the best power with 0.047” gap.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Cheers<o:p></o:p></p><p class=MsoNormal>Chris<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=DE>From:</span></b><span lang=DE> Fot <fot-bounces@autox.team.net> <b>On Behalf Of </b>fubog1 via Fot<br><b>Sent:</b> Thursday, January 11, 2024 8:01 PM<br><b>To:</b> Lorne Fritz <lorne.fritz@gmail.com>; Steven Belfer <steve@artwithcars.com><br><b>Cc:</b> fot@autox.team.net<br><b>Subject:</b> Re: [Fot] Piston to head clearance<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>Steve nailed it, both on the ##s, & the importance of it.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>It depends on what rods & crank, piston to wall clearance & what RPM, but for most applications that's right in the ballpark.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>I've run as little as oops not enough ie .025 or less, .028 minimum (you won't get any carbon deposit on the squish area), but to play it safe nowadays I use .030-.032<o:p></o:p></span></p></div><div><div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>Also on these engines it's not only a CR related issue, the squish is very critical, you want to minimize the clearance between piston top & head to maximize the squish effect, which creates turbulence, which assists in good combustion...<o:p></o:p></span></p></div><div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'>Glen Efinger.<o:p></o:p></span></p></div></div></div></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div></div><div id="ydpeb00682yahoo_quoted_5223032547"><div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'>On Thursday, January 11, 2024 at 01:00:50 PM EST, Steven Belfer via Fot <<a href="mailto:fot@autox.team.net">fot@autox.team.net</a>> wrote: <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'><o:p> </o:p></span></p></div><div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'>You want as little as necessary because this is where your high CR comes from. The thickness of the head gasket is the major part of P to H clearance. I ran .026 P to H clearance at Cal Speedway and the piston kissed the head and I spun a bearing. My machine shop guy likes .040 for safety but I’ve been running .032 and it’s working out great<br>~Steve<br><br><br>> On Jan 11, 2024, at 9:13 AM, Lorne Fritz via Fot <<a href="mailto:fot@autox.team.net" target="_blank">fot@autox.team.net</a>> wrote:<br>> <br>> </span><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#26282A'></span><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'><br>> Hi. In the past I have had pistons hit the head and leave a mark(TR3/4). What piston to head clearance are most of you running? Thanks in advance, Lorne<br>> _______________________________________________<br>> <a href="mailto:fot@autox.team.net" target="_blank">fot@autox.team.net</a><br>> <br>> <a href="http://www.fot-racing.com" target="_blank">http://www.fot-racing.com</a><br>> <br>> Donate: <a href="http://www.team.net/donate.html" target="_blank">http://www.team.net/donate.html</a><br>> Archive: <a href="http://autox.team.net/archive" target="_blank">http://autox.team.net/archive</a> <a href="http://www.team.net/pipermail/fot" target="_blank">http://www.team.net/pipermail/fot</a><br>> Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/fot/steve@artwithcars.com" target="_blank">http://autox.team.net/mailman/options/fot/steve@artwithcars.com</a><o:p></o:p></span></p><div id=ydpeb00682yqtfd30826><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282A'><br>> <br>> <br>_______________________________________________<br><a href="mailto:fot@autox.team.net" target="_blank">fot@autox.team.net</a><br><br><a href="http://www.fot-racing.com" target="_blank">http://www.fot-racing.com</a><br><br>Donate: <a href="http://www.team.net/donate.html" target="_blank">http://www.team.net/donate.html</a><br>Archive: <a href="http://autox.team.net/archive" target="_blank">http://autox.team.net/archive</a> <a href="http://www.team.net/pipermail/fot" target="_blank">http://www.team.net/pipermail/fot</a><br>Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/fot/fubog1@aol.com" target="_blank">http://autox.team.net/mailman/options/fot/fubog1@aol.com</a><br><br><o:p></o:p></span></p></div></div></div></div></div></div></body></html>