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Hi Mike,
Short answer - no. Don't read further unless you have time to spare.
Time to ask you a question - what is the purpose of 'honing'? Save you
thinking (lol), it is to improve the regularity of the surface both in
its geometric shape and its surface finish. (I always thought it was to
make it rounder and smoother but - what do I know.) So it improves a
moving contact between a couple of lumps of metal. ie piston rings to
bore or, rocker shaft to rockers. It reduces friction and enables a
larger surface to surface contact area.Honing reduces friction to a
minimal amount - so ask, does your rocker shaft rotate in the pillars or
do they hold it nice and rigid preventing unwanted fluctuating movements
in a precisely calculated rocker arm movement and position? The pillars
hold it still. So, as a general, background thought - if they are
moving, hone it and if they don't move against each other don't bother.
Now this is not a rule, various surfaces (ie head to block or manifold
flanges to block) do need a tad of honing to make them seat properly and
some extreme honing comes under the guise of 'polishing' but that
doesn't generally improve the geometric qualities - but it can. It is
just a rather loose basic principle.
Have a Merry Christmas and a Happy New Year
------ Original Message ------
From: "Michael MacLean via Spridgets" <spridgets@autox.team.net>
To: "Spridgets" <spridgets@autox.team.net>
Sent: Wednesday, 20 Dec, 23 At 14:25
Subject: [Spridgets] Forged rockers and Hardened Shaft
I acquired a set of forged rockers and a hardened rocker shaft
from David Anton to "build" a new rocker arm assembly. This is for the
new engine I am building to replace the rod knocking 1275 in my Bugeye.
For what it costs, I am committed to put this assembly together. The
one caveat that David told me when he sold me the set of shaft and
rockers was that the rocker bushes had to be honed to fit the shaft.
The hardening process had increased the diameter of the shaft by a
couple of thousands. Not a problem. I found a local shop that can do
it. The rockers should have a clearance of 1 -2 thou for proper
lubrication. The one thing I did not take into account was the pillars.
Should they be honed also? I can find no indication anywhere of the
clearance dimension for the shaft to pillar fit. Knowing that a tight
fit will produce failure and too loose of a fit will drop oil pressure.
A question for you engine builders out there.
Mike MacLean
------------------------
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org=
/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns=3D"http://www.w3.org/1999/xh=
tml"> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charse=
t=3DUTF-8" /> </head> <body><div class=3D"auto-created-dir-div" dir=3D"auto=
" style=3D"unicode-bidi: embed;">Hi Mike,<div><p>Short answer - no. Don=
9;t read further unless you have time to spare.</p><div><p>Time to ask you =
a question - what is the purpose of 'honing'? Save you thinking (l=
ol), it is to improve the regularity of the surface both in its geometric s=
hape and its surface finish. (I always thought it was to make it rounder a=
nd smoother but - what do I know.) So it improves a moving contact between=
a couple of lumps of metal. ie piston rings to bore or, rocker shaft to r=
ockers. It <span style=3D"display: inline !important;">reduces friction an=
d enables a larger surface to surface contact area.</span></p>Honing reduce=
s friction to a minimal amount - so ask, does your rocker shaft rotate in t=
he pillars or do they hold it nice and rigid preventing unwanted fluctuatin=
g movements in a precisely calculated rocker arm movement and position? Th=
e pillars hold it still. So, as a general, background thought - if they ar=
e moving, hone it and if they don't move against each other don't b=
other. Now this is not a rule, various surfaces (ie head to block or mani=
fold flanges to block) do need a tad of honing to make them seat properly a=
nd some extreme honing comes under the guise of 'polishing' but tha=
t doesn't generally improve the geometric qualities - but it can. It i=
s just a rather loose basic principle.</div><div><p><br></p><p>Have a Merry=
Christmas and a Happy New Year</p><p><br></p><p><br></p><blockquote style=
=3D"margin: 0 auto;padding: 0 2.0em;border-left: 2.0px solid rgb(0,173,229)=
;"><br><br>------ Original Message ------<br>From: "Michael MacLean vi=
a Spridgets" <<span class=3D"wt_Email">spridgets@autox.team.net</sp=
an><span></span>><br>To: "Spridgets" <<span class=3D"wt_Ema=
il">spridgets@autox.team.net</span><span></span>><br>Sent: Wednesday, 20=
Dec, 23 At 14:25<br>Subject: [Spridgets] Forged rockers and Hardened Shaft=
<br><br><div dir=3D"ltr"><div> I acquired a set of forged rockers and a=
hardened rocker shaft from David Anton to "build" a new rocker a=
rm assembly. This is for the new engine I am building to replace the rod k=
nocking 1275 in my Bugeye. For what it costs, I am committed to put this a=
ssembly together. The one caveat that David told me when he sold me the se=
t of shaft and rockers was that the rocker bushes had to be honed to fit th=
e shaft. The hardening process had increased the diameter of the shaft by =
a couple of thousands. Not a problem. I found a local shop that can do it=
. The rockers should have a clearance of 1 -2 thou for proper lubrication.=
The one thing I did not take into account was the pillars. Should they b=
e honed also? I can find no indication anywhere of the clearance dimension=
for the shaft to pillar fit. Knowing that a tight fit will produce failure=
and too loose of a fit will drop oil pressure. A question for you engine =
builders out there.</div><div>Mike MacLean <br></div></div> <hr>----------=
--------------<br> <br> <span class=3D"wt_Email"><span class=3D"wt_Email">s=
pridgets@autox.team.net</span><span></span></span><span></span><br> <br> Do=
nate: <a target=3D"_blank" href=3D"http://www.team.net/donate.html";>http://=
www.team.net/donate.html</a><br> Suggested annual donation: $12.75<br> <br>=
Archive: <a target=3D"_blank" href=3D"http://www.team.net/pipermail/spridg=
ets">http://www.team.net/pipermail/spridgets</a> <a target=3D"_blank" href=
=3D"http://autox.team.net/archive";>http://autox.team.net/archive</a><br> <b=
r> Unsubscribe/Manage: <a target=3D"_blank" href=3D"http://autox.team.net/m=
ailman/options/spridgets/grday@btinternet.com">http://autox.team.net/mailma=
n/options/spridgets/grday@btinternet.com</a><br> </blockquote></div></div><=
/div> </body></html>
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