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Re: [Fot] TR Racing cranks- and another question?

To: fubog1@aol.com
Subject: Re: [Fot] TR Racing cranks- and another question?
From: Bill Babcock <Billb@bnj.com>
Date: Fri, 12 Sep 2008 08:51:22 -0700
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It doesn't have to, the spacers just need to keep the rods from moving  
too far. They can be pretty loose, certainly looser than thrust  
bearing clearance. Still, I think it would work a lot better to put  
spacers in the pistons where the movement is relatively slow rocking  
rather than spinning. That's what we came up with for racing two  
stokes--no reason why it couldn't work here as well. I discussed that  
with Uncle Jack, but nothing came of it.

On Sep 12, 2008, at 8:06 AM, fubog1@aol.com wrote:

> Two questions actually...
> 1) the spacers on the pin... does this not induce side thrust loads on
> the piston? This is not good.
> 2) if the BE is narrower, there is excessive cheek clearance. Again, a
> bad thing.
> I'm curious as to how this works in service...?
> Glen
>
>
> -----Original Message-----
> From: Larry Young <cartravel@pobox.com>
> To: Greg Solow <gregmogdoc@surfnetusa.com>
> Cc: FOT <fot@autox.team.net>
> Sent: Fri, 12 Sep 2008 9:47 am
> Subject: Re: [Fot] TR Racing cranks
>
>
>
>
>
> Greg,
>
> To get a larger radius on the crankpins, do you weld the edges and  
> then
> regrind? On my current engine, I welded the edges of the crankpins to
> reduce their width so they would accommodate chevy rods. I them
> reground with a larger radius to reduce the stress riser.  This is a
> cheap approach that addresses both weaknesses, rods and cranks.   
> Others
> on the list have used chevy or other commodity rods, but have used
> spacers at the wrist pin to center the rod. The only problem is that
> welding puts a lot of stresses in the crank and proper nitriding
> requires stress relieving.  The grinder had a hard time getting it
> straight.  He said it was out 0.022 the first time it came out of the
> oven.
>
> Larry Young
>
>
>
> Greg Solow wrote:
>
>
>
>
>
>  A good used crank properly race
> prepared, deep case nitrided and ground with the proper radii on the
> journals, is very reliable at power outputs of up to 16
> 5 hp as long as
> the revs are kept below 6800 rpm. The weak link in bottom end is the
> connecting rod. For use over 6,000 rpm they need to be replaced with
> steel billet rods.
>
>                                                             Greg Solow
>  _______________________________________________
> http://www.team.net/donate.html
>
> Fot mailing list
> Fot@autox.team.net
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>
>
>
> _______________________________________________
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Bill Babcock
Babcock & Jenkins
Billb@bnj.com
503.936.7660
www.bnj.com

Editor
Ke Nalu e-Magazine
Paddlesurfing's Web Journal

Bill@kenalu.com
www.kenalu.com
blog: www.ponohouse.com/ponoblog


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<html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; =
-webkit-line-break: after-white-space; ">It doesn't have to, the spacers =
just need to keep the rods from moving too far. They can be pretty =
loose, certainly looser than thrust bearing clearance. Still, I think it =
would work a lot better to put spacers in the pistons where the movement =
is relatively slow rocking rather than spinning. That's what we came up =
with for racing two stokes--no reason why it couldn't work here as well. =
I discussed that with Uncle Jack, but nothing came of =
it.&nbsp;<div><br><div><div>On Sep 12, 2008, at 8:06 AM, <a =
href=3D"mailto:fubog1@aol.com";>fubog1@aol.com</a> wrote:</div><br =
class=3D"Apple-interchange-newline"><blockquote type=3D"cite"><div>Two =
questions actually...<br>1) the spacers on the pin... does this not =
induce side thrust loads on <br>the piston? This is not good.<br>2) if =
the BE is narrower, there is excessive cheek clearance. Again, a <br>bad =
thing.<br>I'm curious as to how this works in =
service...?<br>Glen<br><br><br>-----Original Message-----<br>From: Larry =
Young &lt;<a =
href=3D"mailto:cartravel@pobox.com";>cartravel@pobox.com</a>><br>To: Greg =
Solow &lt;<a =
href=3D"mailto:gregmogdoc@surfnetusa.com";>gregmogdoc@surfnetusa.com</a>><b=
r>Cc: FOT &lt;<a =
href=3D"mailto:fot@autox.team.net";>fot@autox.team.net</a>><br>Sent: Fri, =
12 Sep 2008 9:47 am<br>Subject: Re: [Fot] TR Racing =
cranks<br><br><br><br><br><br>Greg,<br><br>To get a larger radius on the =
crankpins, do you weld the edges and then<br>regrind? On my current =
engine, I welded the edges of the crankpins to<br>reduce their width so =
they would accommodate chevy rods. I them<br>reground with a larger =
radius to reduce the stress riser.&nbsp; This is a<br>cheap approach =
that addresses both weaknesses, rods and cranks.&nbsp; Others<br>on the =
list have used chevy or other commodity rods, but have used<br>spacers =
at the wrist pin to center the rod. The only problem is that<br>welding =
puts a lot of stresses in the crank and proper nitriding<br>requires =
stress relieving.&nbsp; The grinder had a hard time getting =
it<br>straight.&nbsp; He said it was out 0.022 the first time it came =
out of the<br>oven.<br><br>Larry Young<br><br><br><br>Greg Solow =
wrote:<br><br><br><br><br><br> &nbsp;A good used crank properly =
race<br>prepared, deep case nitrided and ground with the proper radii on =
the<br>journals, is very reliable at power outputs of up to 16<br>5 hp =
as long as<br>the revs are kept below 6800 rpm. The weak link in bottom =
end is the<br>connecting rod. For use over 6,000 rpm they need to be =
replaced with<br>steel billet rods.<br> &nbsp;&nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;<br>&nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; Greg Solow<br> =
&nbsp;_______________________________________________<br><a =
href=3D"http://www.team.net/donate.html";>http://www.team.net/donate.html</=
a><br><br>Fot mailing =
list<br>Fot@autox.team.net<br>http://autox.team.net/mailman/listinfo/fot<b=
r><br><br><br>_______________________________________________<br>http://ww=
w.team.net/donate.html<br><br>Fot mailing =
list<br>Fot@autox.team.net<br>http://autox.team.net/mailman/listinfo/fot<b=
r><br></div></blockquote></div><br><div apple-content-edited=3D"true"> =
<span class=3D"Apple-style-span" style=3D"border-collapse: separate; =
color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; =
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auto; -webkit-text-stroke-width: 0px; "><div style=3D"word-wrap: =
break-word; -webkit-nbsp-mode: space; -webkit-line-break: =
after-white-space; "><span class=3D"Apple-style-span" =
style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: =
Helvetica; font-size: 14px; font-style: normal; font-variant: normal; =
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orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; =
widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; =
-webkit-border-vertical-spacing: 0px; =
-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; "><div style=3D"word-wrap: =
break-word; -webkit-nbsp-mode: space; -webkit-line-break: =
after-white-space; "><div><span class=3D"Apple-style-span" style=3D"color:=
 rgb(118, 15, 79); font-size: 16px; ">Bill Babcock</span></div><div><div =
style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; =
-webkit-line-break: after-white-space; "><div style=3D"word-wrap: =
break-word; -webkit-nbsp-mode: space; -webkit-line-break: =
after-white-space; "><div>Babcock &amp; Jenkins</div><div><a =
href=3D"mailto:Billb@bnj.com";>Billb@bnj.com</a></div><div>503.936.7660</di=
v><div><a href=3D"http://www.bnj.com";>www.bnj.com</a></div><div><br =
class=3D"webkit-block-placeholder"></div><div><div><font =
class=3D"Apple-style-span" color=3D"#010000">Editor</font></div><div><font=
 class=3D"Apple-style-span" color=3D"#010000">Ke Nalu =
e-Magazine</font></div><div><font class=3D"Apple-style-span" =
color=3D"#010000"><font class=3D"Apple-style-span" size=3D"3"><span =
class=3D"Apple-style-span" style=3D"font-size: 12px; =
"><i>Paddlesurfing's Web =
Journal</i></span></font></font></div><div><font =
class=3D"Apple-style-span" color=3D"#010000" size=3D"3"><span =
class=3D"Apple-style-span" style=3D"font-size: 12px; "><i><br =
class=3D"webkit-block-placeholder"></i></span></font></div><div><a =
href=3D"mailto:Bill@kenalu.com";>Bill@kenalu.com</a></div><div><a =
href=3D"http://www.kenalu.com";>www.kenalu.com</a></div><div>blog: <a =
href=3D"http://www.ponohouse.com/ponoblog";>www.ponohouse.com/ponoblog</a><=
/div></div></div></div></div></div></span></div></span></div></span> =
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