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Re: [Spridgets] rocker clearance

To: Hal Faulkner <frog.aye@gmail.com>
Subject: Re: [Spridgets] rocker clearance
From: Rick Fisk via Spridgets <spridgets@autox.team.net>
Date: Sun, 1 Nov 2015 19:04:27 -0500
Cc: Spridgets <spridgets@autox.team.net>
Delivered-to: mharc@autox.team.net
Delivered-to: spridgets@autox.team.net
References: <7A7AC9FC-114F-4A8A-A5FD-E64E2B302659@chartermi.net> <1860081820.239106.1446324593779.JavaMail.yahoo@mail.yahoo.com> <780FEDF366454FDCA816F4F43B8BAD76@Home> <14317D16-7D87-462E-8C94-025161B08310@chartermi.net> <FB4BF17F-C8E0-424F-B825-DAB4A1268E4B@yahoo.com> <CAM6-Rjdz4pgdHEquzVs1=PqYxz6dkqdgQdmqY8vUSamSbUuNQg@mail.gmail.com>
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After thinking the geometry through I have to agree Hal.   Hard to do for an=
 old fart like me.  Thinking it through that is.  LOL

Rick=20

Sent from my keyboard

> On Nov 1, 2015, at 2:46 PM, Hal Faulkner <frog.aye@gmail.com> wrote:
>=20
> Although it feels strange, I will beg to differ with Ron:  Clearance is me=
asured at the valve, but you are really setting the clearance at the cam and=
 follower. Because it is not feasible to measure at the cam/follower, if the=
 rocker ratio is higher you must allow for this and set greater clearance at=
 the valve to compensate.  Stock rockers are 1.25 or 1.3 or something like t=
hat.  To correct for 1.5 rockers you should actually multiply the standard c=
learance by 1.5/1.25 which is 1.2.  1.2 times12 gives us a corrected clearan=
ce of 14.4thou.  That said, this is not a terribly critical setting and depe=
nding on the engine build could be a few thou more.  =20
> Hal
>=20
>> On Sat, Oct 31, 2015 at 5:00 PM, Ron Soave via Spridgets <spridgets@autox=
.team.net> wrote:
>> It doesn't.=20
>>=20
>> Ron Soave
>>=20
>>> On Oct 31, 2015, at 6:16 PM, Rick Fisk via Spridgets <spridgets@autox.te=
am.net> wrote:
>>>=20
>>> Why does increasing the rocker ratio cause a need for more clearance?
>>>=20
>>> Sent from my keyboard
>>>=20
>>>> On Oct 31, 2015, at 6:14 PM, Michael Rowe via Spridgets <spridgets@auto=
x.team.net> wrote:
>>>>=20
>>>> I used Minisport roller rockers bought cheap in the 2008-9 crash.  I no=
 longer remember, but they probably are 1.5 (red), and I also used a "warm" E=
lgin cam that came in a box of parts.
>>>> =20
>>>> Where higher ratio rockers are to be used, the required valve clearance=
 can then be assessed using this simple formula. For instance when using 1.5=
 rockers, you obviously need to multiply the cam/follower clearance by 1.5. S=
o 0.010-in x 1.5 gives 0.015-in for standard/mild cams and 0.012-in x 1.5 gi=
ves 0.018-in for race/more-modified cams. Interestingly, most re-profiled pe=
rformance cams generally have a suggested valve clearance of 0.016-in with s=
tandard ratio rockers. To assess required valve clearance where higher ratio=
 rockers are used simply work it backwards and multiply by the higher ratio.=
 This works out as 0.016-in divided by 1.25 =3D 0.0128, then x 1.5 =3D 0.019=
2" - or 0.019" at the valve.
>>>> ----- Original Message -----
>>>> From: Michael MacLean
>>>> To: Rick Fisk ; Michael Rowe
>>>> Cc: Spridgets
>>>> Sent: Saturday, October 31, 2015 4:49 PM
>>>> Subject: Re: [Spridgets] rocker clearance
>>>>=20
>>>> How about when you have 1.5 rocker arms?  Drove the Bugeye around yeste=
rday.  Runs great, still blue smoke on acceleration on a recent rebuild.  At=
 leat 1000 miles since rebuild.  I'm afraid the rings never seated properly.=
  Not sure of the cylinder wall surface during the rebuild as I did not so t=
hat part of it.
>>>> Mike MacLean
>>>>=20
>>>>=20
>>>>=20
>>>> On Saturday, October 31, 2015 1:26 PM, Rick Fisk via Spridgets <spridge=
ts@autox.team.net> wrote:
>>>>=20
>>>>=20
>>>> The 0.029 in. spec is a whole different thing used when you are assembl=
ing the engine.  If your engine is together and you just want to set the val=
ve clearance it should be 0.012 in. set cold.
>>>>=20
>>>> Sent from my keyboard
>>>>=20
>>>>> On Oct 31, 2015, at 4:06 PM, Michael Rowe via Spridgets <spridgets@aut=
ox.team.net> wrote:
>>>>>=20
>>>>=20
>>>> New 1275 engine.
>>>> Haynes says "Rocker clearance, timing only =3D 0.029 in.
>>>> My mechanic/tutor says, "that is twice what it should be."
>>>> Bentley says:
>>>> Rocker clearance: Running (Standard) =3D 0.012 in. cold
>>>>                                 Running (competition work) =3D 0.015 in=
.
>>>>                                 timing        =3D 0.029 in.
>>>> Online sites agree on  =3D .012 in. cold.
>>>> =20
>>>> So what is the 0.029 in. for?
>>>> =20
>>>> Michael Rowe
>>>>> ------------------------
>>>>>=20
>>>>> spridgets@autox.team.net
>>>>>=20
>>>>> Donate: http://www.team.net/donate.html
>>>>> Suggested annual donation: $12.75
>>>>>=20
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>>>>> Unsubscribe/Manage: http://autox.team.net/mailman/options/spridgets/re=
fisk@chartermi.net
>>>>=20
>>>> ------------------------
>>>>=20
>>>> spridgets@autox.team.net
>>>>=20
>>>> Donate: http://www.team.net/donate.html
>>>> Suggested annual donation: $12.75
>>>>=20
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ngineer.mike@att.net
>>>>=20
>>>>=20
>>>> ------------------------
>>>>=20
>>>> spridgets@autox.team.net
>>>>=20
>>>> Donate: http://www.team.net/donate.html
>>>> Suggested annual donation: $12.75
>>>>=20
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isk@chartermi.net
>>> ------------------------
>>>=20
>>> spridgets@autox.team.net
>>>=20
>>> Donate: http://www.team.net/donate.html
>>> Suggested annual donation: $12.75
>>>=20
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ero@yahoo.com
>>=20
>> ------------------------
>>=20
>> spridgets@autox.team.net
>>=20
>> Donate: http://www.team.net/donate.html
>> Suggested annual donation: $12.75
>>=20
>> Archive: http://www.team.net/archive
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>> Unsubscribe/Manage: http://autox.team.net/mailman/options/spridgets/frog.=
aye@gmail.com
>=20

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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"><div>After thinking the geometry through I h=
ave to agree Hal. &nbsp; Hard to do for an old fart like me. &nbsp;Thinking i=
t through that is. &nbsp;LOL</div><div><br></div><div>Rick&nbsp;<br><br>Sent=
 from my keyboard</div><div><br>On Nov 1, 2015, at 2:46 PM, Hal Faulkner &lt=
;<a href=3D"mailto:frog.aye@gmail.com";>frog.aye@gmail.com</a>&gt; wrote:<br>=
<br></div><blockquote type=3D"cite"><div><div dir=3D"ltr"><div>Although it f=
eels strange, I will beg to differ with Ron:&nbsp; Clearance is <b>measured a=
t the valve</b>, but you are really setting the clearance <b>at the cam and f=
ollower</b>. Because it is not feasible to measure at the cam/follower, if t=
he rocker ratio is higher you must allow for this and set greater clearance a=
t the valve to compensate.&nbsp; Stock rockers are 1.25 or 1.3 or something l=
ike that.&nbsp; To correct for 1.5 rockers you should actually multiply the s=
tandard clearance by 1.5/1.25 which is 1.2.&nbsp; 1.2 times12 gives us a cor=
rected clearance of 14.4thou.&nbsp; That said, this is not a terribly critic=
al setting and depending on the engine build could be a few thou more. &nbsp=
; <br></div>Hal<br></div><div class=3D"gmail_extra"><br><div class=3D"gmail_=
quote">On Sat, Oct 31, 2015 at 5:00 PM, Ron Soave via Spridgets <span dir=3D=
"ltr">&lt;<a href=3D"mailto:spridgets@autox.team.net"; target=3D"_blank">spri=
dgets@autox.team.net</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quo=
te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">=
<div dir=3D"auto"><div>It doesn't.&nbsp;<br><br>Ron Soave</div><div><div cla=
ss=3D"h5"><div><br>On Oct 31, 2015, at 6:16 PM, Rick Fisk via Spridgets &lt;=
<a href=3D"mailto:spridgets@autox.team.net"; target=3D"_blank">spridgets@auto=
x.team.net</a>&gt; wrote:<br><br></div><blockquote type=3D"cite"><div><div>W=
hy does increasing the rocker ratio cause a need for more clearance?<br><br>=
Sent from my keyboard</div><div><br>On Oct 31, 2015, at 6:14 PM, Michael Row=
e via Spridgets &lt;<a href=3D"mailto:spridgets@autox.team.net"; target=3D"_b=
lank">spridgets@autox.team.net</a>&gt; wrote:<br><br></div><blockquote type=3D=
"cite"><div>




<div><font face=3D"Arial">I&nbsp;used Minisport roller rockers bought cheap i=
n the=20
2008-9 crash.&nbsp; I no longer remember, but they probably are 1.5=20
(red),&nbsp;and I also&nbsp;used a "warm" Elgin cam that came in a box of=20=

parts.</font></div>
<div><font face=3D"Arial"></font>&nbsp;</div>
<div><span>Where&nbsp;<a href=3D"http://www.spridgetmania.com/part/C-AHT436/=
Roller-Tipped-15-Ratio-Rockers-Aluminum" target=3D"_blank">higher=20
ratio rockers</a>&nbsp;are to be used, the required valve clearance can then=
 be=20
assessed using this simple formula. For instance when using 1.5 rockers, you=
=20
obviously need to multiply the cam/follower clearance by 1.5. So 0.010-in x 1=
.5=20
gives 0.015-in for standard/mild cams and 0.012-in x 1.5 gives 0.018-in for=20=

race/more-modified cams. Interestingly, most re-profiled performance cams=20=

generally have a suggested valve clearance of 0.016-in with standard ratio=20=

rockers. To assess required valve clearance where higher ratio rockers are u=
sed=20
simply work it backwards and multiply by the higher ratio. This works out as=
=20
0.016-in divided by 1.25 =3D 0.0128, then x 1.5 =3D 0.0192" - or 0.019" at t=
he=20
valve.</span></div>
<blockquote style=3D"BORDER-LEFT:#000000 2px solid;PADDING-LEFT:5px;PADDING-=
RIGHT:0px;MARGIN-LEFT:5px;MARGIN-RIGHT:0px" dir=3D"ltr">
  <div style=3D"FONT:10pt arial">----- Original Message ----- </div>
  <div style=3D"FONT:10pt arial;BACKGROUND:#e4e4e4"><b>From:</b>=20
  <a title=3D"rrengineer.mike@att.net" href=3D"mailto:rrengineer.mike@att.ne=
t" target=3D"_blank">Michael=20
  MacLean</a> </div>
  <div style=3D"FONT:10pt arial"><b>To:</b> <a title=3D"refisk@chartermi.net=
" href=3D"mailto:refisk@chartermi.net"; target=3D"_blank">Rick Fisk</a> ; <a t=
itle=3D"mdrowe@optonline.net" href=3D"mailto:mdrowe@optonline.net"; target=3D=
"_blank">Michael Rowe</a>=20
  </div>
  <div style=3D"FONT:10pt arial"><b>Cc:</b> <a title=3D"spridgets@autox.team=
.net" href=3D"mailto:spridgets@autox.team.net"; target=3D"_blank">Spridgets</=
a> </div>
  <div style=3D"FONT:10pt arial"><b>Sent:</b> Saturday, October 31, 2015 4:4=
9=20
  PM</div>
  <div style=3D"FONT:10pt arial"><b>Subject:</b> Re: [Spridgets] rocker=20
  clearance</div>
  <div><br></div>
  <div style=3D"BACKGROUND-COLOR:#fff;FONT-FAMILY:times new roman,new york,t=
imes,serif;COLOR:#000;FONT-SIZE:16px">
  <div>How about when you have 1.5 rocker=20
  arms?&nbsp; Drove the Bugeye around yesterday.&nbsp; Runs great, still blu=
e=20
  smoke on acceleration on a recent rebuild.&nbsp; At leat 1000 miles since=20=

  rebuild.&nbsp; I'm afraid the rings never seated properly.&nbsp; Not sure o=
f=20
  the cylinder wall surface during the rebuild as I did not so that part of=20=

  it.<br></div>
  <div dir=3D"ltr">Mike MacLean<br></div>
  <div><span></span></div><br>
  <div><br><br></div>
  <div style=3D"DISPLAY:block">
  <div style=3D"FONT-FAMILY:times new roman,new york,times,serif;FONT-SIZE:1=
6px">
  <div style=3D"FONT-FAMILY:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Luc=
ida Grande,sans-serif;FONT-SIZE:16px">
  <div dir=3D"ltr"><font face=3D"Arial" size=3D"2">On Saturday, October 31, 2=
015 1:26 PM,=20
  Rick Fisk via Spridgets &lt;<a href=3D"mailto:spridgets@autox.team.net"; ta=
rget=3D"_blank">spridgets@autox.team.net</a>&gt;=20
  wrote:<br></font></div>
  <blockquote style=3D"BORDER-LEFT:rgb(16,16,255) 2px solid;MARGIN-TOP:5px;P=
ADDING-LEFT:5px;MARGIN-LEFT:5px"><br><br>
    <div>
    <div>
    <div>
    <div>The 0.029 in. spec is a whole different thing used when you are=20
    assembling the engine.&nbsp; If your engine is together and you just wan=
t to=20
    set the valve clearance it should be 0.012 in. set cold.<br clear=3D"non=
e"><br clear=3D"none">Sent from my keyboard</div>
    <div>
    <div><br clear=3D"none">On Oct 31, 2015, at 4:06 PM, Michael Rowe via Sp=
ridgets=20
    &lt;<a href=3D"mailto:spridgets@autox.team.net"; shape=3D"rect" rel=3D"no=
follow" target=3D"_blank">spridgets@autox.team.net</a>&gt;=20
    wrote:<br clear=3D"none"><br clear=3D"none"></div>
    <blockquote type=3D"cite">
      <div></div></blockquote></div></div>
    <div>
   =20
    </div>
    <div>
    <div>
    <div><font face=3D"Arial">New 1275 engine.</font></div>
    <div><font face=3D"Arial">Haynes says "Rocker clearance, timing only=20
    =3D&nbsp;0.029 in.</font></div>
    <div><font face=3D"Arial">My mechanic/tutor says, "that is twice what it=
 should=20
    be."</font></div>
    <div><font face=3D"Arial">Bentley says:</font></div>
    <div><font face=3D"Arial">Rocker clearance: Running (Standard) =3D 0.012=
 in.=20
    cold</font></div>
    <div><font face=3D"Arial">&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
    &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nb=
sp;=20
    &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; Running (competition work) =3D 0.0=
15=20
    in.</font></div>
    <div><font face=3D"Arial">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs=
p;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&n=
bsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=20
    timing&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; =3D 0.029 in.</font></div>
    <div><font face=3D"Arial">Online sites&nbsp;agree on&nbsp; =3D .012 in.=20=

    cold.</font></div>
    <div><font face=3D"Arial"></font>&nbsp;</div>
    <div><font face=3D"Arial">So what is the 0.029 in. for?</font></div>
    <div><font face=3D"Arial"></font>&nbsp;</div>
    <div><font face=3D"Arial">Michael Rowe</font></div></div>
    <blockquote type=3D"cite">
      <div><span>------------------------</span><br clear=3D"none"><span></s=
pan><br clear=3D"none"><span><a href=3D"mailto:spridgets@autox.team.net"; sha=
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<br>
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