Subject: Re: [Fot] FW: Flywheel wt & crank harmonics -TR3/4

From: Peter Vucinic via Fot <[email-masked]>
Date: Tue, 25 Aug 2020 11:11:38 +1000

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Hi Tim,

Good explanation. And 100% right on the effects of the flywheel weight. =
Not to discount the pulley at the front of the crank and its effect =
also.

=20

What you are feeling at around the 5200 mark is the 2nd harmonic of the =
crankshafts natural frequency. The 2nd harmonic is usually the most =
destructive harmonic and this is the crankshaft bending the most during =
rotation. Usually, but not always around the mid distance crank. But can =
be around the 2nd crank journal in the 4 Cyl engine. You will see that a =
lot of people will fit billet, machined, large main bearing cap around =
mid-crank length as they have had issues with either bearing =
=E2=80=98wipe=E2=80=99 of broken cap bolts. They are trying to =
counteract the 2nd harmonic by making the bearing journal stiffer.=20

=20

You don=E2=80=99t need to complete a complex calculation to understand =
what RPM=E2=80=99s you should minimise holding your duration at. The =
crank is suspended and =E2=80=98struck=E2=80=99 and the natural =
frequency that the crank vibrates/resonates at will give you =
it=E2=80=99s harmonic characteristics. Just like a tuning fork. This is =
the basis for setting your RPM=E2=80=99s and multiples of that RPM to =
stay away from. OR you need to reduce the effect at those RPM=E2=80=99s. =
Say, using a harmonic balancer design to reduce the harmonic effect at =
certain RPM=E2=80=99s.

=20

Just as Joe Alexander describes, the first harmonic is in the 2800 RPM =
range, but it is the least destructive so you almost miss feeling it.

=20

Hope that helps?

Have a great day

=20

=20

"You can Make a Small Fortune From Motor Racing. As long as You Started =
With A Lage Fortune!"

Kind Regards

Peter Vucinic

TR4 - TR7 V8 - Spitfire MkII

_______________________________________________

=20

 <http://www.fot-racing.com/> http://www.fot-racing.com

=20

Archive:  <http://www.team.net/archive> http://www.team.net/archive

Forums:  <http://www.team.net/forums> http://www.team.net/forums

=20

=20

=20

=20

From: Fot [mailto:[email-masked]] On Behalf Of timmmurphh--- =
via Fot
Sent: Friday, 22 May 2020 9:08 AM
To: [email-masked]
Subject: [Fot] FW: Flywheel wt & crank harmonics -TR3/4

=20

=20

=20

From: [email-masked] <[email-masked]>=20
Sent: Thursday, May 21, 2020 6:06 PM
To: 'TeriAnn J. Wakeman' <[email-masked]>
Subject: RE: [Fot] Flywheel wt & crank harmonics -TR3/4

=20

The weight of the flywheel will definitely affect the harmonic =
frequency.  The heavier the flywheel, the lower the harmonic frequency =
will be.  The flywheel contributes a significant amount to the total =
rotating inertia due to its weight and that the weight is at greater =
radius than the other rotating masses.  Inertia increases as the square =
of the radius.  It is not a linear function of the radius.

=20

An RPM of 5200 was mentioned as the harmonic resonance.  I had always =
heard that it was more like 6300 RPM.  I have never seen a calculation =
for it.  It would be complex.  Note that lighter pistons and connecting =
rods would tend to lower the harmonic frequency as they would reduce the =
inertia in the engine.

=20

Tim Murphy

=20

From: Fot <[email-masked]> On Behalf Of TeriAnn J. Wakeman =
via Fot
Sent: Thursday, May 21, 2020 2:44 PM
To: FOT <[email-masked]>
Subject: [Fot] Flywheel wt & crank harmonics -TR3/4

=20

Something I have wondered about for years.

Does the weight of the flywheel affect the RPM and intensity of =
harmonics inherent in a TR3/4 stock crank? I've never found an answer to =
that question.

TeriAnn

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<o:idmap v:ext=3D"edit" data=3D"1" />
</o:shapelayout></xml><![endif]--></head><body lang=3DEN-AU =
link=3D"#0563C1" vlink=3D"#954F72"><div class=3DWordSection1><p =
class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'>Hi =
Tim,<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'>Good explanation. And 100% =
right on the effects of the flywheel weight. Not to discount the pulley =
at the front of the crank and its effect also.<o:p></o:p></span></p><p =
class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'>What =
you are feeling at around the 5200 mark is the 2<sup>nd</sup> harmonic =
of the crankshafts natural frequency. The 2<sup>nd</sup> harmonic is =
usually the most destructive harmonic and this is the crankshaft bending =
the most during rotation. Usually, but not always around the mid =
distance crank. But can be around the 2<sup>nd</sup> crank journal in =
the 4 Cyl engine. You will see that a lot of people will fit billet, =
machined, large main bearing cap around mid-crank length as they have =
had issues with either bearing =E2=80=98wipe=E2=80=99 of broken cap =
bolts. They are trying to counteract the 2<sup>nd</sup> harmonic by =
making the bearing journal stiffer. <o:p></o:p></span></p><p =
class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'>You =
don=E2=80=99t need to complete a complex calculation to understand what =
RPM=E2=80=99s you should minimise holding your duration at. The crank is =
suspended and =E2=80=98struck=E2=80=99 and the natural frequency that =
the crank vibrates/resonates at will give you it=E2=80=99s harmonic =
characteristics. Just like a tuning fork. This is the basis for setting =
your RPM=E2=80=99s and multiples of that RPM to stay away from. OR you =
need to reduce the effect at those RPM=E2=80=99s. Say, using a harmonic =
balancer design to reduce the harmonic effect at certain =
RPM=E2=80=99s.<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'>Just as =
Joe Alexander describes, the first harmonic is in the 2800 RPM range, =
but it is the least destructive so you almost miss feeling =
it.<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'>Hope =
that helps?<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'>Have a great =
day<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><p =
class=3DMsoNormal><b><span lang=3DEN-US =
style=3D'color:#7030A0'>&quot;You can Make a Small Fortune From Motor =
Racing. As long as You Started With A Lage =
Fortune!&quot;<o:p></o:p></span></b></p><p class=3DMsoNormal><span =
lang=3DEN-US style=3D'color:#1F497D'>Kind =
Regards<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'color:#1F497D'>Peter Vucinic<o:p></o:p></span></p><p =
class=3DMsoNormal><span lang=3DEN-US style=3D'color:#1F497D'>TR4 - TR7 =
V8 - Spitfire MkII<o:p></o:p></span></p><p class=3DMsoNormal><span =
lang=3DEN-US =
style=3D'color:#1F497D'>_______________________________________________<o=
:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'><a =
href=3D"mailto:[email-masked]"><span =
style=3D'color:blue'>[email-masked]</span></a><o:p></o:p></span></p><=
p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'><o:p>&nbsp;=
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n></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'><o:p>&nbsp;=
</o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'>Donate: <a =
href=3D"http://www.team.net/donate.html"><span =
style=3D'color:blue'>http://www.team.net/donate.html</span></a><o:p></o:p=
></span></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'>Archive: =
<a href=3D"http://www.team.net/archive"><span =
style=3D'color:blue'>http://www.team.net/archive</span></a><o:p></o:p></s=
pan></p><p class=3DMsoNormal><span lang=3DEN-US =
style=3D'font-size:10.5pt;font-family:Consolas;color:#1F497D'>Forums: <a =
href=3D"http://www.team.net/forums"><span =
style=3D'color:blue'>http://www.team.net/forums</span></a><o:p></o:p></sp=
an></p><p class=3DMsoNormal><span =
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class=3DMsoNormal><span =
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class=3DMsoNormal><span style=3D'font-size:14.0pt;color:#1F497D'> =
<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:14.0pt;color:#1F497D'>=C2=A0<o:p></o:p></span></p><p =
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style=3D'font-size:14.0pt;color:#1F497D'><o:p>&nbsp;</o:p></span></p><div=
><div style=3D'border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt =
0cm 0cm 0cm'><p class=3DMsoNormal style=3D'margin-left:36.0pt'><b><span =
lang=3DEN-US =
style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span>=
</b><span lang=3DEN-US =
style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Fot =
[mailto:[email-masked]] <b>On Behalf Of </b>timmmurphh--- =
via Fot<br><b>Sent:</b> Friday, 22 May 2020 9:08 AM<br><b>To:</b> =
[email-masked]<br><b>Subject:</b> [Fot] FW: Flywheel wt &amp; crank =
harmonics -TR3/4<o:p></o:p></span></p></div></div><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><o:p>&nbsp;</o:p></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><div><div =
style=3D'border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm =
0cm 0cm'><p class=3DMsoNormal style=3D'margin-left:36.0pt'><b><span =
lang=3DEN-US>From:</span></b><span lang=3DEN-US> [email-masked] =
&lt;[email-masked]&gt; <br><b>Sent:</b> Thursday, May 21, 2020 =
6:06 PM<br><b>To:</b> 'TeriAnn J. Wakeman' =
&lt;[email-masked]&gt;<br><b>Subject:</b> RE: [Fot] Flywheel wt =
&amp; crank harmonics -TR3/4<o:p></o:p></span></p></div></div><p =
class=3DMsoNormal style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span lang=3DEN-US>The weight of the =
flywheel will definitely affect the harmonic frequency.&nbsp; The =
heavier the flywheel, the lower the harmonic frequency will be.&nbsp; =
The flywheel contributes a significant amount to the total rotating =
inertia due to its weight and that the weight is at greater radius than =
the other rotating masses.&nbsp; Inertia increases as the square of the =
radius.&nbsp; It is not a linear function of the =
radius.<o:p></o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span lang=3DEN-US>An RPM of 5200 was =
mentioned as the harmonic resonance.&nbsp; I had always heard that it =
was more like 6300 RPM.&nbsp; I have never seen a calculation for =
it.&nbsp; It would be complex.&nbsp; Note that lighter pistons and =
connecting rods would tend to lower the harmonic frequency as they would =
reduce the inertia in the engine.<o:p></o:p></span></p><p =
class=3DMsoNormal style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span lang=3DEN-US>Tim =
Murphy<o:p></o:p></span></p><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><div><div =
style=3D'border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm =
0cm 0cm'><p class=3DMsoNormal style=3D'margin-left:36.0pt'><b><span =
lang=3DEN-US>From:</span></b><span lang=3DEN-US> Fot &lt;<a =
href=3D"mailto:[email-masked]">[email-masked]</a>=
&gt; <b>On Behalf Of </b>TeriAnn J. Wakeman via Fot<br><b>Sent:</b> =
Thursday, May 21, 2020 2:44 PM<br><b>To:</b> FOT &lt;<a =
href=3D"mailto:[email-masked]">[email-masked]</a>&gt;<br><b>Subje=
ct:</b> [Fot] Flywheel wt &amp; crank harmonics =
-TR3/4<o:p></o:p></span></p></div></div><p class=3DMsoNormal =
style=3D'margin-left:36.0pt'><span =
lang=3DEN-US><o:p>&nbsp;</o:p></span></p><p =
style=3D'margin-left:36.0pt'><span lang=3DEN-US =
style=3D'font-size:13.5pt;font-family:"Adobe =
Garamond","serif"'>Something I have wondered about for =
years.</span><span lang=3DEN-US><o:p></o:p></span></p><p =
style=3D'margin-left:36.0pt'><span lang=3DEN-US =
style=3D'font-size:13.5pt;font-family:"Adobe Garamond","serif"'>Does the =
weight of the flywheel affect the RPM and intensity of harmonics =
inherent in a TR3/4 stock crank? I've never found an answer to that =
question.</span><span lang=3DEN-US><o:p></o:p></span></p><p =
style=3D'margin-left:36.0pt'><span lang=3DEN-US =
style=3D'font-size:13.5pt;font-family:"Adobe =
Garamond","serif"'>TeriAnn</span><span =
lang=3DEN-US><o:p></o:p></span></p></div></body></html>
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_______________________________________________
[email-masked]

http://www.fot-racing.com

Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot

--===============2152113774981090352==--

---

From: Phil Gott via Fot <[email-masked]>
Date: Tue, 25 Aug 2020 07:36:33 -0400

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Sent from my iPhone

> On Aug 24, 2020, at 9:13 PM, Peter Vucinic via Fot <[email-masked]> wr=
ote:
>=20
> =EF=BB=BF
> Hi Tim,
> Good explanation. And 100% right on the effects of the flywheel weight. No=
t to discount the pulley at the front of the crank and its effect also.
> =20
> What you are feeling at around the 5200 mark is the 2nd harmonic of the cr=
ankshafts natural frequency. The 2nd harmonic is usually the most destructiv=
e harmonic and this is the crankshaft bending the most during rotation. Usua=
lly, but not always around the mid distance crank. But can be around the 2nd=
 crank journal in the 4 Cyl engine. You will see that a lot of people will f=
it billet, machined, large main bearing cap around mid-crank length as they h=
ave had issues with either bearing =E2=80=98wipe=E2=80=99 of broken cap bolt=
s. They are trying to counteract the 2nd harmonic by making the bearing jour=
nal stiffer.
> =20
> You don=E2=80=99t need to complete a complex calculation to understand wha=
t RPM=E2=80=99s you should minimise holding your duration at. The crank is s=
uspended and =E2=80=98struck=E2=80=99 and the natural frequency that the cra=
nk vibrates/resonates at will give you it=E2=80=99s harmonic characteristics=
. Just like a tuning fork. This is the basis for setting your RPM=E2=80=99s a=
nd multiples of that RPM to stay away from. OR you need to reduce the effect=
 at those RPM=E2=80=99s. Say, using a harmonic balancer design to reduce the=
 harmonic effect at certain RPM=E2=80=99s.
> =20
> Just as Joe Alexander describes, the first harmonic is in the 2800 RPM ran=
ge, but it is the least destructive so you almost miss feeling it.
> =20
> Hope that helps?
> Have a great day
> =20
> =20
> "You can Make a Small Fortune =46rom Motor Racing. As long as You Started W=
ith A Lage Fortune!"
> Donate: http://www.team.net/donate.html
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> =20
> =20
> =20
> =20
> From: Fot [mailto:[email-masked]] On Behalf Of timmmurphh--- v=
ia Fot
> The weight of the flywheel will definitely affect the harmonic frequency. =
 The heavier the flywheel, the lower the harmonic frequency will be.  The fl=
ywheel contributes a significant amount to the total rotating inertia due to=
 its weight and that the weight is at greater radius than the other rotating=
 masses.  Inertia increases as the square of the radius.  It is not a linear=
 function of the radius.
> =20
> An RPM of 5200 was mentioned as the harmonic resonance.  I had always hear=
d that it was more like 6300 RPM.  I have never seen a calculation for it.  I=
t would be complex.  Note that lighter pistons and connecting rods would ten=
d to lower the harmonic frequency as they would reduce the inertia in the en=
gine.
> =20
> Tim Murphy
> =20
> From: Fot <[email-masked]> On Behalf Of TeriAnn J. Wakeman via=
 Fot
> Does the weight of the flywheel affect the RPM and intensity of harmonics i=
nherent in a TR3/4 stock crank? I've never found an answer to that question.=

> Donate: http://www.team.net/donate.html
> Unsubscribe/Manage: http://autox.team.net/mailman/options/fot/vfracing@aol=
.com

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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><br><br><div dir=3D"ltr">Sent from my iPhon=
e</div><div dir=3D"ltr"><br><blockquote type=3D"cite">On Aug 24, 2020, at 9:=
13 PM, Peter Vucinic via Fot &lt;[email-masked]&gt; wrote:<br><br></bloc=
kquote></div><blockquote type=3D"cite"><div dir=3D"ltr">=EF=BB=BF<meta http-=
equiv=3D"Content-Type" content=3D"text/html; charset=3Dutf-8"><meta name=3D"=
Generator" content=3D"Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class=3D"WordSection1"><p class=3D"Ms=
oNormal"><span style=3D"font-size:14.0pt;color:#1F497D">Hi Tim,<o:p></o:p></=
span></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#1F497=
D">Good explanation. And 100% right on the effects of the flywheel weight. N=
ot to discount the pulley at the front of the crank and its effect also.<o:p=
></o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;col=
or:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal"><span style=3D=
"font-size:14.0pt;color:#1F497D">What you are feeling at around the 5200 mar=
k is the 2<sup>nd</sup> harmonic of the crankshafts natural frequency. The 2=
<sup>nd</sup> harmonic is usually the most destructive harmonic and this is t=
he crankshaft bending the most during rotation. Usually, but not always arou=
nd the mid distance crank. But can be around the 2<sup>nd</sup> crank journa=
l in the 4 Cyl engine. You will see that a lot of people will fit billet, ma=
chined, large main bearing cap around mid-crank length as they have had issu=
es with either bearing =E2=80=98wipe=E2=80=99 of broken cap bolts. They are t=
rying to counteract the 2<sup>nd</sup> harmonic by making the bearing journa=
l stiffer. <o:p></o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-=
size:14.0pt;color:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal=
"><span style=3D"font-size:14.0pt;color:#1F497D">You don=E2=80=99t need to c=
omplete a complex calculation to understand what RPM=E2=80=99s you should mi=
nimise holding your duration at. The crank is suspended and =E2=80=98struck=E2=
=80=99 and the natural frequency that the crank vibrates/resonates at will g=
ive you it=E2=80=99s harmonic characteristics. Just like a tuning fork. This=
 is the basis for setting your RPM=E2=80=99s and multiples of that RPM to st=
ay away from. OR you need to reduce the effect at those RPM=E2=80=99s. Say, u=
sing a harmonic balancer design to reduce the harmonic effect at certain RPM=
=E2=80=99s.<o:p></o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-=
size:14.0pt;color:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal=
"><span style=3D"font-size:14.0pt;color:#1F497D">Just as Joe Alexander descr=
ibes, the first harmonic is in the 2800 RPM range, but it is the least destr=
uctive so you almost miss feeling it.<o:p></o:p></span></p><p class=3D"MsoNo=
rmal"><span style=3D"font-size:14.0pt;color:#1F497D"><o:p>&nbsp;</o:p></span=
></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#1F497D">H=
ope that helps?<o:p></o:p></span></p><p class=3D"MsoNormal"><span style=3D"f=
ont-size:14.0pt;color:#1F497D">Have a great day<o:p></o:p></span></p><p clas=
s=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#1F497D"><o:p>&nbsp;</=
o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:=
#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal"><b><span lang=3D=
"EN-US" style=3D"color:#7030A0">"You can Make a Small Fortune =46rom Motor R=
acing. As long as You Started With A Lage Fortune!"<o:p></o:p></span></b></p=
><p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"color:#1F497D">Kind Re=
gards<o:p></o:p></span></p><p class=3D"MsoNormal"><span lang=3D"EN-US" style=
=3D"color:#1F497D">Peter Vucinic<o:p></o:p></span></p><p class=3D"MsoNormal"=
><span lang=3D"EN-US" style=3D"color:#1F497D">TR4 - TR7 V8 - Spitfire MkII<o=
:p></o:p></span></p><p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"col=
or:#1F497D">_______________________________________________<o:p></o:p></span=
></p><p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:10.5pt;f=
ont-family:Consolas;color:#1F497D"><a href=3D"mailto:[email-masked]"><sp=
an style=3D"color:blue">[email-masked]</span></a><o:p></o:p></span></p><=
p class=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:10.5pt;font-fa=
mily:Consolas;color:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNorm=
al"><span lang=3D"EN-US" style=3D"font-size:10.5pt;font-family:Consolas;colo=
r:#1F497D"><a href=3D"http://www.fot-racing.com/"><span style=3D"color:blue"=
>http://www.fot-racing.com</span></a><o:p></o:p></span></p><p class=3D"MsoNo=
rmal"><span lang=3D"EN-US" style=3D"font-size:10.5pt;font-family:Consolas;co=
lor:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal"><span lang=3D=
"EN-US" style=3D"font-size:10.5pt;font-family:Consolas;color:#1F497D">Donate=
: <a href=3D"http://www.team.net/donate.html"><span style=3D"color:blue">htt=
p://www.team.net/donate.html</span></a><o:p></o:p></span></p><p class=3D"Mso=
Normal"><span lang=3D"EN-US" style=3D"font-size:10.5pt;font-family:Consolas;=
color:#1F497D">Archive: <a href=3D"http://www.team.net/archive"><span style=3D=
"color:blue">http://www.team.net/archive</span></a><o:p></o:p></span></p><p c=
lass=3D"MsoNormal"><span lang=3D"EN-US" style=3D"font-size:10.5pt;font-famil=
y:Consolas;color:#1F497D">Forums: <a href=3D"http://www.team.net/forums"><sp=
an style=3D"color:blue">http://www.team.net/forums</span></a><o:p></o:p></sp=
an></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#1F497D"=
><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-size=
:14.0pt;color:#1F497D"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNormal"><s=
pan style=3D"font-size:14.0pt;color:#1F497D"> <o:p></o:p></span></p><p class=
=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#1F497D">&nbsp;<o:p></o=
:p></span></p><p class=3D"MsoNormal"><span style=3D"font-size:14.0pt;color:#=
1F497D"><o:p>&nbsp;</o:p></span></p><div><div style=3D"border:none;border-to=
p:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p class=3D"MsoNormal" styl=
e=3D"margin-left:36.0pt"><b><span lang=3D"EN-US" style=3D"font-size:10.0pt;f=
ont-family:&quot;Tahoma&quot;,&quot;sans-serif&quot;">From:</span></b><span l=
ang=3D"EN-US" style=3D"font-size:10.0pt;font-family:&quot;Tahoma&quot;,&quot=
;sans-serif&quot;"> Fot [mailto:[email-masked]] <b>On Behalf Of <=
/b>timmmurphh--- via Fot<br><b>Sent:</b> Friday, 22 May 2020 9:08 AM<br><b>T=
o:</b> [email-masked]<br><b>Subject:</b> [Fot] FW: Flywheel wt &amp; cra=
nk harmonics -TR3/4<o:p></o:p></span></p></div></div><p class=3D"MsoNormal" s=
tyle=3D"margin-left:36.0pt"><o:p>&nbsp;</o:p></p><p class=3D"MsoNormal" styl=
e=3D"margin-left:36.0pt"><span lang=3D"EN-US"><o:p>&nbsp;</o:p></span></p><p=
 class=3D"MsoNormal" style=3D"margin-left:36.0pt"><span lang=3D"EN-US"><o:p>=
&nbsp;</o:p></span></p><div><div style=3D"border:none;border-top:solid #E1E1=
E1 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p class=3D"MsoNormal" style=3D"margin-l=
eft:36.0pt"><b><span lang=3D"EN-US">From:</span></b><span lang=3D"EN-US"> ti=
[email-masked] &lt;[email-masked]&gt; <br><b>Sent:</b> Thursday, M=
ay 21, 2020 6:06 PM<br><b>To:</b> 'TeriAnn J. Wakeman' &lt;[email-masked]=
om&gt;<br><b>Subject:</b> RE: [Fot] Flywheel wt &amp; crank harmonics -TR3/4=
<o:p></o:p></span></p></div></div><p class=3D"MsoNormal" style=3D"margin-lef=
t:36.0pt"><span lang=3D"EN-US"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoNo=
rmal" style=3D"margin-left:36.0pt"><span lang=3D"EN-US">The weight of the fl=
ywheel will definitely affect the harmonic frequency.&nbsp; The heavier the f=
lywheel, the lower the harmonic frequency will be.&nbsp; The flywheel contri=
butes a significant amount to the total rotating inertia due to its weight a=
nd that the weight is at greater radius than the other rotating masses.&nbsp=
; Inertia increases as the square of the radius.&nbsp; It is not a linear fu=
nction of the radius.<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"m=
argin-left:36.0pt"><span lang=3D"EN-US"><o:p>&nbsp;</o:p></span></p><p class=
=3D"MsoNormal" style=3D"margin-left:36.0pt"><span lang=3D"EN-US">An RPM of 5=
200 was mentioned as the harmonic resonance.&nbsp; I had always heard that i=
t was more like 6300 RPM.&nbsp; I have never seen a calculation for it.&nbsp=
; It would be complex.&nbsp; Note that lighter pistons and connecting rods w=
ould tend to lower the harmonic frequency as they would reduce the inertia i=
n the engine.<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"margin-le=
ft:36.0pt"><span lang=3D"EN-US"><o:p>&nbsp;</o:p></span></p><p class=3D"MsoN=
ormal" style=3D"margin-left:36.0pt"><span lang=3D"EN-US">Tim Murphy<o:p></o:=
p></span></p><p class=3D"MsoNormal" style=3D"margin-left:36.0pt"><span lang=3D=
"EN-US"><o:p>&nbsp;</o:p></span></p><div><div style=3D"border:none;border-to=
p:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p class=3D"MsoNormal" styl=
e=3D"margin-left:36.0pt"><b><span lang=3D"EN-US">From:</span></b><span lang=3D=
"EN-US"> Fot &lt;<a href=3D"mailto:[email-masked]">fot-bounces@a=
utox.team.net</a>&gt; <b>On Behalf Of </b>TeriAnn J. Wakeman via Fot<br><b>S=
ent:</b> Thursday, May 21, 2020 2:44 PM<br><b>To:</b> FOT &lt;<a href=3D"mai=
lto:[email-masked]">[email-masked]</a>&gt;<br><b>Subject:</b> [Fot] =
Flywheel wt &amp; crank harmonics -TR3/4<o:p></o:p></span></p></div></div><p=
 class=3D"MsoNormal" style=3D"margin-left:36.0pt"><span lang=3D"EN-US"><o:p>=
&nbsp;</o:p></span></p><p style=3D"margin-left:36.0pt"><span lang=3D"EN-US" s=
tyle=3D"font-size:13.5pt;font-family:&quot;Adobe Garamond&quot;,&quot;serif&=
quot;">Something I have wondered about for years.</span><span lang=3D"EN-US"=
><o:p></o:p></span></p><p style=3D"margin-left:36.0pt"><span lang=3D"EN-US" s=
tyle=3D"font-size:13.5pt;font-family:&quot;Adobe Garamond&quot;,&quot;serif&=
quot;">Does the weight of the flywheel affect the RPM and intensity of harmo=
nics inherent in a TR3/4 stock crank? I've never found an answer to that que=
stion.</span><span lang=3D"EN-US"><o:p></o:p></span></p><p style=3D"margin-l=
eft:36.0pt"><span lang=3D"EN-US" style=3D"font-size:13.5pt;font-family:&quot=
;Adobe Garamond&quot;,&quot;serif&quot;">TeriAnn</span><span lang=3D"EN-US">=
<o:p></o:p></span></p></div><span>__________________________________________=
_____</span><br><span>[email-masked]</span><br><span></span><br><span>ht=
tp://www.fot-racing.com</span><br><span></span><br><span>Donate: http://www.=
team.net/donate.html</span><br><span>Archive: http://autox.team.net/archive h=
ttp://www.team.net/pipermail/fot</span><br><span>Unsubscribe/Manage: http://=
autox.team.net/mailman/options/fot/[email-masked]</span><br><span></span><=
br><span></span><br></div></blockquote></body></html>=

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