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Good point.
On Thu, Jan 11, 2024 at 6:45=E2=80=AFPM <tr4racing@googlemail.com> wrote:
> That is one thing to consider.
>
> When is turbulence supporting and when is turbulence overdone and
> disturbing.
>
>
>
> 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.
>
> That=E2=80=99s why we had the best power with 0.047=E2=80=9D gap.
>
>
>
> Cheers
>
> Chris
>
>
>
>
>
> *From:* Fot <fot-bounces@autox.team.net> *On Behalf Of *fubog1 via Fot
> *Sent:* Thursday, January 11, 2024 8:01 PM
> *To:* Lorne Fritz <lorne.fritz@gmail.com>; Steven Belfer <
> steve@artwithcars.com>
> *Cc:* fot@autox.team.net
> *Subject:* Re: [Fot] Piston to head clearance
>
>
>
> Steve nailed it, both on the ##s, & the importance of it.
>
> It depends on what rods & crank, piston to wall clearance & what RPM, but
> for most applications that's right in the ballpark.
>
> 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
>
> Also on these engines it's not only a CR related issue, the squish is ver=
y
> critical, you want to minimize the clearance between piston top & head to
> maximize the squish effect, which creates turbulence, which assists in go=
od
> combustion...
>
>
>
> Glen Efinger.
>
>
>
>
>
> On Thursday, January 11, 2024 at 01:00:50 PM EST, Steven Belfer via Fot <
> fot@autox.team.net> wrote:
>
>
>
>
>
> 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=E2=80=99ve been running .032 and it=E2=80=99s working out gr=
eat
> ~Steve
>
>
> > On Jan 11, 2024, at 9:13=E2=80=AFAM, Lorne Fritz via Fot <fot@autox.tea=
m.net>
> wrote:
> >
> > =EF=BB=BF
> > 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? Than=
ks
> in advance, Lorne
> > _______________________________________________
> > fot@autox.team.net
> >
> > http://www.fot-racing.com
> >
> > Donate: http://www.team.net/donate.html
> > Archive: http://autox.team.net/archive http://www.team.net/pipermail/fo=
t
> > Unsubscribe/Manage:
> http://autox.team.net/mailman/options/fot/steve@artwithcars.com
>
>
> >
> >
> _______________________________________________
> fot@autox.team.net
>
> http://www.fot-racing.com
>
> Donate: http://www.team.net/donate.html
> Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
> Unsubscribe/Manage:
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>
>
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<div dir=3D"ltr">Good point. <br></div><br><div class=3D"gmail_quote"><div =
dir=3D"ltr" class=3D"gmail_attr">On Thu, Jan 11, 2024 at 6:45=E2=80=AFPM &l=
t;<a href=3D"mailto:tr4racing@googlemail.com";>tr4racing@googlemail.com</a>&=
gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0=
px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div =
class=3D"msg986188904719810780"><div style=3D"overflow-wrap: break-word;" l=
ang=3D"EN-US"><div class=3D"m_986188904719810780WordSection1"><p class=3D"M=
soNormal">That is one thing to consider.<u></u><u></u></p><p class=3D"MsoNo=
rmal">When is turbulence supporting and when is turbulence overdone and dis=
turbing.<u></u><u></u></p><p class=3D"MsoNormal"><u></u>=C2=A0<u></u></p><p=
class=3D"MsoNormal">I could imagine to force too much turbulence with a ve=
ry small squish gap the flame front expansion is compromised, thus slows do=
wn, and lowers the hp output.<u></u><u></u></p><p class=3D"MsoNormal">That=
=E2=80=99s why we had the best power with 0.047=E2=80=9D gap.<u></u><u></u>=
</p><p class=3D"MsoNormal"><u></u>=C2=A0<u></u></p><p class=3D"MsoNormal">C=
heers<u></u><u></u></p><p class=3D"MsoNormal">Chris<u></u><u></u></p><p cla=
ss=3D"MsoNormal"><u></u>=C2=A0<u></u></p><p class=3D"MsoNormal"><u></u>=C2=
=A0<u></u></p><div><div style=3D"border-color:rgb(225,225,225) currentcolor=
currentcolor;border-style:solid none none;border-width:1pt medium medium;p=
adding:3pt 0cm 0cm"><p class=3D"MsoNormal"><b><span lang=3D"DE">From:</span=
></b><span lang=3D"DE"> Fot <<a href=3D"mailto:fot-bounces@autox.team.ne=
t" target=3D"_blank">fot-bounces@autox.team.net</a>> <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 <<a href=3D"mailto:lorne.fritz@gmail.com"; target=3D"_b=
lank">lorne.fritz@gmail.com</a>>; Steven Belfer <<a href=3D"mailto:st=
eve@artwithcars.com" target=3D"_blank">steve@artwithcars.com</a>><br><b>=
Cc:</b> <a href=3D"mailto:fot@autox.team.net"; target=3D"_blank">fot@autox.t=
eam.net</a><br><b>Subject:</b> Re: [Fot] Piston to head clearance<u></u><u>=
</u></span></p></div></div><p class=3D"MsoNormal"><u></u>=C2=A0<u></u></p><=
div><div><p class=3D"MsoNormal"><span style=3D"font-size:12pt;font-family:&=
quot;Arial",sans-serif">Steve nailed it, both on the ##s, & the im=
portance of it.<u></u><u></u></span></p></div><div><p class=3D"MsoNormal"><=
span style=3D"font-size:12pt;font-family:"Arial",sans-serif">It d=
epends on what rods & crank, piston to wall clearance & what RPM, b=
ut for most applications that's right in the ballpark.<u></u><u></u></s=
pan></p></div><div><p class=3D"MsoNormal"><span style=3D"font-size:12pt;fon=
t-family:"Arial",sans-serif">I've run as little as oops not e=
nough ie .025 or less, .028 minimum (you won't get any carbon deposit o=
n the squish area), but to play it safe nowadays I use .030-.032<u></u><u><=
/u></span></p></div><div><div><div><p class=3D"MsoNormal"><span style=3D"fo=
nt-size:12pt;font-family:"Arial",sans-serif">Also on these engine=
s it's not only a CR related issue, the squish is very critical, you wa=
nt to minimize the clearance between piston top & head to maximize the =
squish effect, which creates turbulence, which assists in good combustion..=
.<u></u><u></u></span></p></div><div><div><p class=3D"MsoNormal"><span styl=
e=3D"font-size:12pt;font-family:"Arial",sans-serif"><u></u>=C2=A0=
<u></u></span></p></div><div><div><p class=3D"MsoNormal"><span style=3D"fon=
t-size:12pt;font-family:"Arial",sans-serif">Glen Efinger.<u></u><=
u></u></span></p></div></div></div></div><div><p class=3D"MsoNormal"><span =
style=3D"font-size:12pt;font-family:"Arial",sans-serif"><u></u>=
=C2=A0<u></u></span></p></div></div><div><p class=3D"MsoNormal"><span style=
=3D"font-size:12pt;font-family:"Arial",sans-serif"><u></u>=C2=A0<=
u></u></span></p></div></div><div id=3D"m_986188904719810780ydpeb00682yahoo=
_quoted_5223032547"><div><div><p class=3D"MsoNormal"><span style=3D"font-si=
ze:10pt;font-family:"Helvetica",sans-serif;color:rgb(38,40,42)">O=
n Thursday, January 11, 2024 at 01:00:50 PM EST, Steven Belfer via Fot <=
<a href=3D"mailto:fot@autox.team.net"; target=3D"_blank">fot@autox.team.net<=
/a>> wrote: <u></u><u></u></span></p></div><div><p class=3D"MsoNormal"><=
span style=3D"font-size:10pt;font-family:"Helvetica",sans-serif;c=
olor:rgb(38,40,42)"><u></u>=C2=A0<u></u></span></p></div><div><p class=3D"M=
soNormal"><span style=3D"font-size:10pt;font-family:"Helvetica",s=
ans-serif;color:rgb(38,40,42)"><u></u>=C2=A0<u></u></span></p></div><div><d=
iv><p class=3D"MsoNormal"><span style=3D"font-size:10pt;font-family:"H=
elvetica",sans-serif;color:rgb(38,40,42)">You want as little as necess=
ary because this is where your high CR comes from.=C2=A0 The thickness of t=
he head gasket is the major part of P to H clearance.=C2=A0 I ran .026 P to=
H clearance at Cal Speedway and the piston kissed the head and I spun a be=
aring.=C2=A0 My machine shop guy likes .040 for safety but I=E2=80=99ve bee=
n running .032 and it=E2=80=99s working out great<br>~Steve<br><br><br>>=
On Jan 11, 2024, at 9:13=E2=80=AFAM, Lorne Fritz via Fot <<a href=3D"ma=
ilto:fot@autox.team.net" target=3D"_blank">fot@autox.team.net</a>> wrote=
:<br>> <br>> </span><span style=3D"font-size:10pt;font-family:"T=
ahoma",sans-serif;color:rgb(38,40,42)">=EF=BB=BF</span><span style=3D"=
font-size:10pt;font-family:"Helvetica",sans-serif;color:rgb(38,40=
,42)"><br>> Hi.=C2=A0 In the past I have had pistons hit the head and le=
ave a mark(TR3/4).=C2=A0 What piston to head clearance are most of you runn=
ing? Thanks in advance,=C2=A0 Lorne<br>> _______________________________=
________________<br>> <a href=3D"mailto:fot@autox.team.net"; target=3D"_b=
lank">fot@autox.team.net</a><br>> <br>> <a href=3D"http://www.fot-rac=
ing.com" target=3D"_blank">http://www.fot-racing.com</a><br>> <br>> D=
onate: <a href=3D"http://www.team.net/donate.html"; target=3D"_blank">http:/=
/www.team.net/donate.html</a><br>> Archive: <a href=3D"http://autox.team=
.net/archive" target=3D"_blank">http://autox.team.net/archive</a> <a href=
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t/pipermail/fot</a><br>> Unsubscribe/Manage: <a href=3D"http://autox.tea=
m.net/mailman/options/fot/steve@artwithcars.com" target=3D"_blank">http://a=
utox.team.net/mailman/options/fot/steve@artwithcars.com</a><u></u><u></u></=
span></p><div id=3D"m_986188904719810780ydpeb00682yqtfd30826"><p class=3D"M=
soNormal" style=3D"margin-bottom:12pt"><span style=3D"font-size:10pt;font-f=
amily:"Helvetica",sans-serif;color:rgb(38,40,42)"><br>> <br>&g=
t; <br>_______________________________________________<br><a href=3D"mailto=
:fot@autox.team.net" target=3D"_blank">fot@autox.team.net</a><br><br><a hre=
f=3D"http://www.fot-racing.com"; target=3D"_blank">http://www.fot-racing.com=
</a><br><br>Donate: <a href=3D"http://www.team.net/donate.html"; target=3D"_=
blank">http://www.team.net/donate.html</a><br>Archive: <a href=3D"http://au=
tox.team.net/archive" target=3D"_blank">http://autox.team.net/archive</a> <=
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eam.net/pipermail/fot</a><br>Unsubscribe/Manage: <a href=3D"http://autox.te=
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</p></div></div></div></div></div></div></div></div></blockquote></div>
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_______________________________________________
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http://www.fot-racing.com
Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
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