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

To: "fot@autox.team.net" <fot@autox.team.net>, fubog1 <fubog1@aol.com>
Subject: Re: [Fot] FW: Flywheel wt & crank harmonics -TR3/4
From: barry rosenberg via Fot <fot@autox.team.net>
Date: Fri, 22 May 2020 12:57:40 +0000 (UTC)
Delivered-to: mharc@autox.team.net
Delivered-to: fot@autox.team.net
References: <4c3df97e-1249-1566-2c8a-9068d0a947fa@gmail.com> <016b01d62fc4$735d05e0$5a1711a0$@gmail.com> <017201d62fc4$a328bda0$e97a38e0$@gmail.com> <1917981001.2205864.1590146889094@mail.yahoo.com> x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36
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 Back in 1980, Fred Baker won the run-offs at Road Atlanta in a Jag XKE. On=
e thing that he said helped was making the flywheel and harmonic damper as =
close to the same weight as possible. He used some big American car damper.=
 They had trouble making maximum RPM and ran the engine on a dyno with a st=
robe light on the flywheel and noticed a severe flex to the crank. They inc=
reased the damper weight and the vibration was reduced giving close to 1,00=
0 more RPM. The cranks "wiggle" at high RPM. Matching the weight at both en=
ds reduced that. They did blow the engine the next week when giving writers=
 a test ride. I used this theory on my TR4A using a factory crank that I mo=
dified and lightened, I used an ATI custom damper and a lightened aluminum =
flywheel (less than 18 lbs for flywheel, PP and disc) and was able to turn =
the engine to 7,300. I also used a custom 1/4" plate bolted to the oil pan =
rail and across to the center main caps. Maybe some one can get more info o=
n this theory.
Barry Rosenberg
    On Friday, May 22, 2020, 07:32:38 AM EDT, fubog1 via Fot <fot@autox.tea=
m.net> wrote: =20
=20
 =20

Note that lighter pistons and connecting rods=20
 That's a BIG gain, it gets some of that recip/bending load out of the main=
s.=20
Glen
=20
=20
-----Original Message-----
From: timmmurphh--- via Fot <fot@autox.team.net>
To: fot@autox.team.net
Sent: Thu, May 21, 2020 7:07 pm
Subject: [Fot] FW: Flywheel wt & crank harmonics -TR3/4

=C2=A0 =C2=A0From: timmmurphh@gmail.com <timmmurphh@gmail.com>=20
Sent: Thursday, May 21, 2020 6:06 PM
To: 'TeriAnn J. Wakeman' <tjwakeman@gmail.com>
Subject: RE: [Fot] Flywheel wt & crank harmonics -TR3/4 =C2=A0The weight of=
 the flywheel will definitely affect the harmonic frequency.=C2=A0 The heav=
ier the flywheel, the lower the harmonic frequency will be.=C2=A0 The flywh=
eel contributes a significant amount to the total rotating inertia due to i=
ts weight and that the weight is at greater radius than the other rotating =
masses.=C2=A0 Inertia increases as the square of the radius.=C2=A0 It is no=
t a linear function of the radius. =C2=A0An RPM of 5200 was mentioned as th=
e harmonic resonance.=C2=A0 I had always heard that it was more like 6300 R=
PM.=C2=A0 I have never seen a calculation for it.=C2=A0 It would be complex=
.=C2=A0 Note that lighter pistons and connecting rods would tend to lower t=
he harmonic frequency as they would reduce the inertia in the engine. =C2=
=A0Tim Murphy =C2=A0From: Fot <fot-bounces@autox.team.net> On Behalf Of Ter=
iAnn J. Wakeman via Fot
Sent: Thursday, May 21, 2020 2:44 PM
To: FOT <fot@autox.team.net>
Subject: [Fot] Flywheel wt & crank harmonics -TR3/4 =C2=A0Something 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 a=
n answer to that question.TeriAnn__________________________________________=
_____
fot@autox.team.net

http://www.fot-racing.com

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


_______________________________________________
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south.net


 =20
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<html><head></head><body><div class=3D"ydp8792e147yahoo-style-wrap" style=
=3D"font-family: Helvetica Neue, Helvetica, Arial, sans-serif; font-size: 1=
3px;"><div></div>
        <div dir=3D"ltr" data-setdir=3D"false">Back in 1980, Fred Baker won=
 the run-offs at Road Atlanta in a Jag XKE. One thing that he said helped w=
as making the flywheel and harmonic damper as close to the same weight as p=
ossible. He used some big American car damper. They had trouble making maxi=
mum RPM and ran the engine on a dyno with a strobe light on the flywheel an=
d noticed a severe flex to the crank. They increased the damper weight and =
the vibration was reduced giving close to 1,000 more RPM. The cranks "wiggl=
e" at high RPM. Matching the weight at both ends reduced that. They did blo=
w the engine the next week when giving writers a test ride. I used this the=
ory on my TR4A using a factory crank that I modified and lightened, I used =
an ATI custom damper and a lightened aluminum flywheel (less than 18 lbs fo=
r flywheel, PP and disc) and was able to turn the engine to 7,300. I also u=
sed a custom 1/4" plate bolted to the oil pan rail and across to the center=
 main caps. Maybe some one can get more info on this theory.</div><div dir=
=3D"ltr" data-setdir=3D"false"><br></div><div dir=3D"ltr" data-setdir=3D"fa=
lse">Barry Rosenberg</div><div><br></div>
       =20
        </div><div id=3D"ydpe5e743b0yahoo_quoted_0878910077" class=3D"ydpe5=
e743b0yahoo_quoted">
            <div style=3D"font-family:'Helvetica Neue', Helvetica, Arial, s=
ans-serif;font-size:13px;color:#26282a;">
               =20
                <div>
                    On Friday, May 22, 2020, 07:32:38 AM EDT, fubog1 via Fo=
t &lt;fot@autox.team.net&gt; wrote:
                </div>
                <div><br></div>
                <div><br></div>
                <div><div id=3D"ydpe5e743b0yiv0974681257"><div><div style=
=3D"color: black; font-style: normal; font-weight: normal; font-stretch: no=
rmal; font-size: 10pt; line-height: normal; font-family: Arial, Helvetica, =
sans-serif;">
<div> <br clear=3D"none">
</div>

<div style=3D"font-family:arial, helvetica;font-size:10pt;color:black;"><bl=
ockquote style=3D"border-left:2px solid blue;padding-left:3px;">Note that l=
ighter pistons and connecting rods </blockquote></div>

<div> <font size=3D"2">That's a BIG gain, it gets some of that recip/bendin=
g load out of the mains. <br clear=3D"none">
</font></div>

<div><font size=3D"2">Glen</font><br clear=3D"none">
</div>

<div> <br clear=3D"none">
</div>

<div> <br clear=3D"none">
</div>

<div style=3D"font-family:arial, helvetica;font-size:10pt;color:black;">---=
--Original Message-----<br clear=3D"none">
From: timmmurphh--- via Fot &lt;fot@autox.team.net&gt;<br clear=3D"none">
To: fot@autox.team.net<br clear=3D"none">
Sent: Thu, May 21, 2020 7:07 pm<br clear=3D"none">
Subject: [Fot] FW:  Flywheel wt &amp; crank harmonics -TR3/4<br clear=3D"no=
ne">
<br clear=3D"none">

<div class=3D"ydpe5e743b0yiv0974681257yqt2563533873" id=3D"ydpe5e743b0yiv09=
74681257yqt85619"><div id=3D"ydpe5e743b0yiv0974681257">
<div>
<div class=3D"ydpe5e743b0yiv0974681257WordSection1">
<div class=3D"ydpe5e743b0yiv0974681257MsoNormal">&nbsp;</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div>
<div style=3D"border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in =
0in 0in;">
<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"><b>From:</b> timmmurphh@gm=
ail.com &lt;timmmurphh@gmail.com&gt; <br clear=3D"none">
<b>Sent:</b> Thursday, May 21, 2020 6:06 PM<br clear=3D"none">
<b>To:</b> 'TeriAnn J. Wakeman' &lt;tjwakeman@gmail.com&gt;<br clear=3D"non=
e">
<b>Subject:</b> RE: [Fot] Flywheel wt &amp; crank harmonics -TR3/4</div>
</div>
</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal">The weight of the flywheel=
 will definitely affect the harmonic frequency.&nbsp; The heavier the flywh=
eel, the lower the harmonic frequency will be.&nbsp; The flywheel contribut=
es 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 fu=
nction of the radius.</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal">An RPM of 5200 was mention=
ed as the harmonic resonance.&nbsp; I had always heard that it was more lik=
e 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 engin=
e.</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal">Tim Murphy</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div>
<div style=3D"border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in =
0in 0in;">
<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"><b>From:</b> Fot &lt;<a sh=
ape=3D"rect" href=3D"mailto:fot-bounces@autox.team.net"; rel=3D"nofollow" ta=
rget=3D"_blank">fot-bounces@autox.team.net</a>&gt; <b>On Behalf Of </b>Teri=
Ann J. Wakeman via Fot<br clear=3D"none">
<b>Sent:</b> Thursday, May 21, 2020 2:44 PM<br clear=3D"none">
<b>To:</b> FOT &lt;<a shape=3D"rect" href=3D"mailto:fot@autox.team.net"; rel=
=3D"nofollow" target=3D"_blank">fot@autox.team.net</a>&gt;<br clear=3D"none=
">
<b>Subject:</b> [Fot] Flywheel wt &amp; crank harmonics -TR3/4</div>
</div>
</div>

<div class=3D"ydpe5e743b0yiv0974681257MsoNormal"> &nbsp;</div>

<div><span style=3D"font-size:13.5pt;font-family:serif;">Something I have w=
ondered about for years.</span></div>

<div><span style=3D"font-size:13.5pt;font-family: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></div>

<div><span style=3D"font-size:13.5pt;font-family:serif;">TeriAnn</span></di=
v>
</div>
</div>
</div></div>
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