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Re: [Fot] Piston to head clearance

To: "'fubog1'" <fubog1@aol.com>, "'Lorne Fritz'" <lorne.fritz@gmail.com>, <tr4racing@googlemail.com>, "'Ken Knight'" <kknight@klaenv.com>
Subject: Re: [Fot] Piston to head clearance
From: Chris Marx via Fot <fot@autox.team.net>
Date: Fri, 12 Jan 2024 17:46:41 +0100
Cc: fot@autox.team.net
Delivered-to: mharc@autox.team.net
Delivered-to: fot@autox.team.net
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The measurements were made on a rolling road=E2=80=A6.BUT on the rolling =
road at the Nurburging.

This dyno was in charge to measure the balance of performance power of =
the race cars under controlled regulations.

This dyno was equipped with a custom made software to be most exact. You =
can say the reference dyno.

=20

Why did we get a little gain?

My GUESS -  Two things come into play:

1.      Turbulence =E2=80=93 turbulence is good to the point when it gets so =
strong that it blows the flame out or it pushes against the flame front =
and hinder it
2.      Mathematical=E2=80=A6.assuming that you can make the gap zero between =
piston and head. The TR=E2=80=99s do have a chamber half the size of the =
piston surface. If you get the gap down to zero the pressure of the =
combustion forces on half of the piston deck: Force =3D pressure x area. =
If the area is half the size, the force is half as strong. Certainly =
this is only true on TDC as soon the piston moves downwards the full =
area of the piston deck comes in to play again.

=20

I guess, these little things might make this little gain happen.

But, I=E2=80=99m not an engine developer, I only make some thoughts =
about it=E2=80=A6maybe not true and the result is just luck.

On the other hand=E2=80=A6..my car has many wins with standard crank and =
standard valve sizes. Does perform quite nice and seem to hold together.

=20

Cheers

Chris

=20

=20

From: fubog1 <fubog1@aol.com>=20
Sent: Friday, January 12, 2024 5:30 PM
To: Lorne Fritz <lorne.fritz@gmail.com>; tr4racing@googlemail.com; Ken =
Knight <kknight@klaenv.com>
Cc: fot@autox.team.net
Subject: Re: [Fot] Piston to head clearance

=20

I'm still burning up (precious) brain cells on this, yes interesting, =
but that's one of my questions also, exactly how was the reported gain =
established?

I've always gone with the theory that more is better when it comes to =
turbulence, which requires minimal squish clearance.

I would imagine that chamber & piston top configuration, ie flat-tops or =
a lump on top, may be part of the equation as well...

Yes compelling discussion!

=20

Glen Efinger

=20

On Friday, January 12, 2024 at 10:57:08 AM EST, Ken Knight =

=20

=20

Interesting discussion and I would agree on point.  What would =
interesting to know is how the HP change was measured; chassis dyno or =
engine dyno?

=20

Ken=20

=20

Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=3D550986>  for =
Windows

=20

Sent: Friday, January 12, 2024 7:13 AM
Subject: Re: [Fot] Piston to head clearance

=20

Good point.=20

=20

On Thu, Jan 11, 2024 at 6:45=E2=80=AFPM <tr4racing@googlemail.com =

That is one thing to consider.

When is turbulence supporting and when is turbulence overdone and =
disturbing.

=20

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.

=20

Cheers

Chris

=20

=20

From: Fot <fot-bounces@autox.team.net =
Sent: Thursday, January 11, 2024 8:01 PM
Subject: Re: [Fot] Piston to head clearance

=20

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 =
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...

=20

Glen Efinger.

=20

=20

On Thursday, January 11, 2024 at 01:00:50 PM EST, Steven Belfer via Fot =

=20

=20

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 great
~Steve


> On Jan 11, 2024, at 9:13=E2=80=AFAM, Lorne Fritz via Fot =
>=20
> =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? =
Thanks in advance,  Lorne
> _______________________________________________
>=20
> http://www.fot-racing.com
>=20
> Donate: http://www.team.net/donate.html
> Archive: http://autox.team.net/archive =
http://www.team.net/pipermail/fot
> Unsubscribe/Manage: =
http://autox.team.net/mailman/options/fot/steve@artwithcars.com


>=20
>=20
_______________________________________________

http://www.fot-racing.com

Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
http://autox.team.net/mailman/options/fot/fubog1@aol.com

=20


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</o:shapelayout></xml><![endif]--></head><body lang=3DEN-US link=3Dblue =
vlink=3Dpurple style=3D'word-wrap:break-word'><div =
class=3DWordSection1><p class=3DMsoNormal>The measurements were made on =
a rolling road=E2=80=A6.BUT on the rolling road at the =
Nurburging.<o:p></o:p></p><p class=3DMsoNormal>This dyno was in charge =
to measure the balance of performance power of the race cars under =
controlled regulations.<o:p></o:p></p><p class=3DMsoNormal>This dyno was =
equipped with a custom made software to be most exact. You can say the =
reference dyno.<o:p></o:p></p><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p><p class=3DMsoNormal>Why did we =
get a little gain?<o:p></o:p></p><p class=3DMsoNormal>My GUESS - =
=C2=A0Two things come into play:<o:p></o:p></p><ol =
style=3D'margin-top:0cm' start=3D1 type=3D1><li class=3DMsoListParagraph =
style=3D'margin-left:0cm;mso-list:l0 level1 lfo1'>Turbulence =E2=80=93 =
turbulence is good to the point when it gets so strong that it blows the =
flame out or it pushes against the flame front and hinder =
it<o:p></o:p></li><li class=3DMsoListParagraph =
style=3D'margin-left:0cm;mso-list:l0 level1 =
lfo1'>Mathematical=E2=80=A6.assuming that you can make the gap zero =
between piston and head. The TR=E2=80=99s do have a chamber half the =
size of the piston surface. If you get the gap down to zero the pressure =
of the combustion forces on half of the piston deck: Force =3D pressure =
x area. If the area is half the size, the force is half as strong. =
Certainly this is only true on TDC as soon the piston moves downwards =
the full area of the piston deck comes in to play =
again.<o:p></o:p></li></ol><p class=3DMsoNormal><o:p>&nbsp;</o:p></p><p =
class=3DMsoNormal>I guess, these little things might make this little =
gain happen.<o:p></o:p></p><p class=3DMsoNormal>But, I=E2=80=99m not an =
engine developer, I only make some thoughts about it=E2=80=A6maybe not =
true and the result is just luck.<o:p></o:p></p><p class=3DMsoNormal>On =
the other hand=E2=80=A6..my car has many wins with standard crank and =
standard valve sizes. Does perform quite nice and seem to hold =
together.<o:p></o:p></p><p class=3DMsoNormal><o:p>&nbsp;</o:p></p><p =
class=3DMsoNormal>Cheers<o:p></o:p></p><p =
class=3DMsoNormal>Chris<o:p></o:p></p><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p><div><div =
style=3D'border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm =
0cm 0cm'><p class=3DMsoNormal><b><span lang=3DDE>From:</span></b><span =
lang=3DDE> fubog1 &lt;fubog1@aol.com&gt; <br><b>Sent:</b> Friday, =
January 12, 2024 5:30 PM<br><b>To:</b> Lorne Fritz =
&lt;lorne.fritz@gmail.com&gt;; tr4racing@googlemail.com; Ken Knight =
&lt;kknight@klaenv.com&gt;<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=3DMsoNormal><o:p>&nbsp;</o:p></p><div><div><p =
class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'>I'm still =
burning up (precious) brain cells on this, yes interesting, but that's =
one of my questions also, exactly how was the reported gain =
established?<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'>I've always =
gone with the theory that more is better when it comes to turbulence, =
which requires minimal squish =
clearance.<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'>I would =
imagine that chamber &amp; piston top configuration, ie flat-tops or a =
lump on top, may be part of the equation as =
well...<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'>Yes compelling =
discussion!<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'><o:p>&nbsp;</o:=
p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'>Glen =
Efinger<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif'><o:p>&nbsp;</o:=
p></span></p></div></div><div =
id=3D"ydp3da3111dyahoo_quoted_5967812695"><div><div><p =
class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>On Friday, January 12, 2024 at 10:57:08 AM EST, Ken Knight &lt;<a =
href=3D"mailto:kknight@klaenv.com";>kknight@klaenv.com</a>&gt; wrote: =
<o:p></o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p>&nbsp;</o:p></span></p></div><div><p class=3DMsoNormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p>&nbsp;</o:p></span></p></div><div><div =
id=3Dydp3da3111dyiv6692933316><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Interesting discussion and I would agree on point.&nbsp; What would =
interesting to know is how the HP change was measured; chassis dyno or =
engine dyno?<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Ken <o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Sent from <a =
href=3D"https://go.microsoft.com/fwlink/?LinkId=3D550986"; =
target=3D"_blank">Mail</a> for Windows<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><div =
id=3Dydp3da3111dyiv6692933316yqt61391><div =
style=3D'border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0cm =
0cm 0cm;border-color:currentcolor currentcolor'><p =
class=3Dydp3da3111dyiv6692933316msonormal><b><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>From: </span></b><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><a href=3D"mailto:fot@autox.team.net"; target=3D"_blank">Lorne Fritz =
via Fot</a><br><b>Sent: </b>Friday, January 12, 2024 7:13 AM<br><b>To: =
</b><a href=3D"mailto:tr4racing@googlemail.com"; =
target=3D"_blank">tr4racing@googlemail.com</a><br><b>Cc: </b><a =
href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a>; <a =
href=3D"mailto:fubog1@aol.com"; =
target=3D"_blank">fubog1</a><br><b>Subject: </b>Re: [Fot] Piston to head =
clearance<o:p></o:p></span></p></div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Good point. <o:p></o:p></span></p></div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>On Thu, Jan 11, 2024 at 6:45=E2=80=AFPM &lt;<a =
href=3D"mailto:tr4racing@googlemail.com"; =
target=3D"_blank">tr4racing@googlemail.com</a>&gt; =
wrote:<o:p></o:p></span></p></div><blockquote =
style=3D'border:none;border-left:solid windowtext 1.0pt;padding:0cm 0cm =
0cm =
6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5=
.0pt;border-color:currentcolor currentcolor currentcolor rgb(204, 204, =
204)'><div><div><div><p class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>That is one thing to consider.<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>When is turbulence supporting and when is turbulence overdone and =
disturbing.<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>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></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>That=E2=80=99s why we had the best power with 0.047=E2=80=9D =
gap.<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Cheers<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>Chris<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><div><div =
style=3D'border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0cm =
0cm 0cm;border-color:currentcolor'><p =
class=3Dydp3da3111dyiv6692933316msonormal><b><span lang=3DDE =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>From:</span></b><span lang=3DDE =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'> Fot &lt;<a href=3D"mailto:fot-bounces@autox.team.net"; =
target=3D"_blank">fot-bounces@autox.team.net</a>&gt; <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 &lt;<a =
href=3D"mailto:lorne.fritz@gmail.com"; =
target=3D"_blank">lorne.fritz@gmail.com</a>&gt;; Steven Belfer &lt;<a =
href=3D"mailto:steve@artwithcars.com"; =
target=3D"_blank">steve@artwithcars.com</a>&gt;<br><b>Cc:</b> <a =
href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a><br><b>Subject:</b> Re: [Fot] =
Piston to head clearance</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div></div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>S=
teve nailed it, both on the ##s, &amp; the importance of it.</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>I=
t depends on what rods &amp; crank, piston to wall clearance &amp; what =
RPM, but for most applications that's right in the ballpark.</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>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</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>A=
lso 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 =
&amp; head to maximize the squish effect, which creates turbulence, =
which assists in good combustion...</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>&=
nbsp;</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>G=
len Efinger.</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div></div></div></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>&=
nbsp;</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:12.0pt;font-family:"Arial",sans-serif;color:#26282A'>&=
nbsp;</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div></div><div =
id=3D"ydp3da3111dyiv6692933316m_986188904719810780ydpeb00682yahoo_quoted_=
5223032547"><div><div><p class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'>O=
n Thursday, January 11, 2024 at 01:00:50 PM EST, Steven Belfer via Fot =
&lt;<a href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a>&gt; wrote: </span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'>&=
nbsp;</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'>&=
nbsp;</span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><div><div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'>Y=
ou want as little as necessary because this is where your high CR comes =
from.&nbsp; The thickness of the head gasket is the major part of P to H =
clearance.&nbsp; I ran .026 P to H clearance at Cal Speedway and the =
piston kissed the head and I spun a bearing.&nbsp; My machine shop guy =
likes .040 for safety but I=E2=80=99ve been running .032 and =
it=E2=80=99s working out great<br>~Steve<br><br><br>&gt; On Jan 11, =
2024, at 9:13=E2=80=AFAM, Lorne Fritz via Fot &lt;<a =
href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a>&gt; wrote:<br>&gt; <br>&gt; =
</span><span =
style=3D'font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#26282A'>=
=EF=BB=BF</span><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'><=
br>&gt; Hi.&nbsp; In the past I have had pistons hit the head and leave =
a mark(TR3/4).&nbsp; What piston to head clearance are most of you =
running? Thanks in advance,&nbsp; Lorne<br>&gt; =
_______________________________________________<br>&gt; <a =
href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a><br>&gt; <br>&gt; <a =
href=3D"http://www.fot-racing.com"; =
target=3D"_blank">http://www.fot-racing.com</a><br>&gt; <br>&gt; Donate: =
<a href=3D"http://www.team.net/donate.html"; =
target=3D"_blank">http://www.team.net/donate.html</a><br>&gt; Archive: =
<a href=3D"http://autox.team.net/archive"; =
target=3D"_blank">http://autox.team.net/archive</a> <a =
href=3D"http://www.team.net/pipermail/fot"; =
target=3D"_blank">http://www.team.net/pipermail/fot</a><br>&gt; =
href=3D"http://autox.team.net/mailman/options/fot/steve@artwithcars.com"; =
target=3D"_blank">http://autox.team.net/mailman/options/fot/steve@artwith=
cars.com</a></span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div></div></div></div></div></div></div></bloc=
kquote></div><p class=3Dydp3da3111dyiv6692933316msonormal =
style=3D'mso-margin-top-alt:5.0pt;margin-right:0cm;margin-bottom:12.0pt;m=
argin-left:4.8pt'><span =
style=3D'font-size:10.0pt;font-family:"Arial",sans-serif;color:#26282A'><=
br>&gt; <br>&gt; =
<br>_______________________________________________<br><a =
href=3D"mailto:fot@autox.team.net"; =
target=3D"_blank">fot@autox.team.net</a><br><br><a =
href=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://autox.team.net/archive"; =
target=3D"_blank">http://autox.team.net/archive</a> <a =
href=3D"http://www.team.net/pipermail/fot"; =
target=3D"_blank">http://www.team.net/pipermail/fot</a><br>Unsubscribe/Ma=
nage: <a =
href=3D"http://autox.team.net/mailman/options/fot/fubog1@aol.com"; =
target=3D"_blank">http://autox.team.net/mailman/options/fot/fubog1@aol.co=
m</a></span><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'><o:p></o:p></span></p></div><p =
class=3Dydp3da3111dyiv6692933316msonormal><span =
style=3D'font-size:10.0pt;font-family:"Helvetica",sans-serif;color:#26282=
A'>&nbsp;<o:p></o:p></span></p></div></div></div></div></div></div></div>=
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