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Millions of opinions; just google 'bronze vs iron valve guides.'
Generally, bronze guides have less friction, but that's probably not an issue
for a stock build. Also, bronze tends to cause less galling of the valve stem.
Note using bronze inserts in iron guides is popular. Note also that if the
guides are reamed too wide you'll get too much oil down the guide which can
'coke' and cause sticking; this happens fairly often in piston aircraft engines
which, like motorcycle engines are air-cooled and usually (I THINK) use bronze
guides.
what's the advantage to bronze guides?
Ira Erbs
Portland,OR
1959 BN4 100-6
with BT7 engine and disk brakes.
On Wed, Jan 27, 2016 at 8:07 AM, Bob Spidell < bspidell@comcast.net > wrote:
I think the 'trick' is to ream extra clearance in the guides (esp. the
exhaust). We didn't give specific instructions to the guy who built my head,
but he is a race engine builder and probably knew to do this.
Or maybe I just got lucky.
Bob
I have used bronze valve guides and have always had trouble with them, I've
made them work but it's always been a hassle. I don't do it anymore.
Cheers, Henry Morrison, Albuquerque, NM
Sure wish I'd read that article before I put 110K miles--still going strong--on
my BJ8 with stock iron head and bronze valve guides.
Bob
Great article and sleuth work on figuring out why bronze guides and cast iron
heads are a bad idea in this month's Healey Marque Magazine. Love the technical
jargon, ie all black and yucky. Good job explaining all the technical stuff.
Cheers
Mr. Ira Erbs
Portland,OR
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<html><body><div style=3D"font-family: Arial; font-size: 12pt; color: #0000=
00"><div>Millions of opinions; just google 'bronze vs iron valve guides.'<b=
r></div><div><br></div><div>Generally, bronze guides have less friction, bu=
t that's probably not an issue for a stock build. Also, bronze tends =
to cause less galling of the valve stem. Note using bronze inserts in=
iron guides is popular. Note also that if the guides are reamed too =
wide you'll get too much oil down the guide which can 'coke' and cause stic=
king; this happens fairly often in piston aircraft engines which, like moto=
rcycle engines are air-cooled and usually (I THINK) use bronze guides.<br><=
/div><div><br></div><div><br></div><div style=3D"color:#000;font-weight:nor=
mal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans=
-serif;font-size:12pt;"><br><div><br></div><div dir=3D"ltr">what's the adva=
ntage to bronze guides?</div><div class=3D"gmail_extra"><br clear=3D"all"><=
div><div class=3D"gmail_signature"><div dir=3D"ltr"><div><div dir=3D"ltr">I=
ra Erbs<div>Portland,OR</div><div>1959 BN4 100-6</div><div>with BT7 engine =
and disk brakes.</div></div></div></div></div></div>
<br><div class=3D"gmail_quote">On Wed, Jan 27, 2016 at 8:07 AM, Bob Spidell=
<span dir=3D"ltr"><<a href=3D"mailto:bspidell@comcast.net"; target=3D"_b=
lank">bspidell@comcast.net</a>></span> wrote:<br><blockquote class=3D"gm=
ail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-le=
ft:1ex"><div><div style=3D"font-family:Arial;font-size:12pt;color:#000000">=
<div>I think the 'trick' is to ream extra clearance in the guides (esp. the=
exhaust). We didn't give specific instructions to the guy who built =
my head, but he is a race engine builder and probably knew to do this.<br><=
/div><div><br></div><div>Or maybe I just got lucky. <br></div><span c=
lass=3D"HOEnZb"><span style=3D"color: #888888;" data-mce-style=3D"color: #8=
88888;" color=3D"#888888"><div><br></div><div>Bob<br></div><div><br></div><=
/span></span><div style=3D"color:#000;font-weight:normal;font-style:normal;=
text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt"=
><br><div><br></div>
<div dir=3D"ltr"><span class=3D"">I have used bronze valve guides and =
have always had trouble with them, I've made them work but it's a=
lways been a hassle. I don't do it anymore.<br> <br>Cheers, Henr=
y Morrison, Albuquerque, NM<br><div><br></div></span><div><hr><br><span cla=
ss=3D""><div><br></div><div style=3D"color:rgb(0,0,0);font-family:Arial;fon=
t-size:12pt"><div>Sure wish I'd read that article before I put 110K miles--=
still going strong--on my BJ8 with stock iron head and bronze valve guides.=
<br></div><div><br></div><div>Bob<br></div><div><br></div><hr><div style=3D=
"color:rgb(0,0,0);font-family:Helvetica,Arial,sans-serif;font-size:12pt;fon=
t-style:normal;font-weight:normal;text-decoration:none"><br><div><br></div>=
<p dir=3D"ltr">Great article and sleuth work on figuring out why bronze gui=
des and cast iron heads are a bad idea in this month's Healey Marque Magazi=
ne. Love the technical jargon, ie all black and yucky. Good job explaining =
all the technical stuff.<br> Cheers</p><p dir=3D"ltr">Mr. Ira Erbs<br> Port=
land,OR</p><br><div><br></div></div></div></span></div> =09=09 =09 =09=09=
</div>
</div><div><br></div></div></div></blockquote></div><br></div>
</div><div><br></div></div></body></html>
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