--===============6869980409328415796==
Content-Language: en-US
boundary="_000_DM6PR07MB453803FB848355453FEFA5A9A5870DM6PR07MB4538namp_"
--_000_DM6PR07MB453803FB848355453FEFA5A9A5870DM6PR07MB4538namp_
Content-Transfer-Encoding: quoted-printable
I disagree that valve clearances are not critical. As the engine comes up t=
o temperature the metal parts of the valve train (valves, lifters, push rod=
s, the head itself and the rocker shaft towers) increase in length and the =
valve clearances are calculated to assure that this expansion isn't allowed=
to affect the sealing of the valves on their seats. If the valves are set =
too tight they reach a point where they won't touch the seats and therefore=
won't seal. Hot gases rushing through the gaps will quickly erode the valv=
es. Also increasing the duration and/or lift of the cam has the effect of t=
he decreasing the length of the opening and closing ramps on the back side=
of the cam This reduces the length of time (dwell) the valve remains on th=
e seat. Increasing the valve clearance restores the dwell time the valve ne=
eds to transfer its heat load to the cooling system through the valve seat =
and the cylinder head. Too little dwell time or the lack of proper valve se=
aling are two causes of burned valves.
In my own experience I installed an Isky cam with a grind a little more agg=
ressive than the 100M cam and set the clearances to 0.012" per the manual. =
Within about 2,000 miles the exhaust valves were trashed. I then took the t=
ime to read the Isky installation instructions which specifically state the=
valve clearance needs to be set to 0.018". I re-installed the head with ne=
w valves and set them to Isky's spec and never had another problem with bur=
ned valves.
Follow the cam grinder's recommendations and you will avoid trouble.
Bill Lawrence
BN1 #554
________________________________
From: Healeys <healeys-bounces@autox.team.net> on behalf of Bob Spidell <bs=
pidell@comcast.net>
Sent: Saturday, January 12, 2019 11:10 PM
To: Michael MacLean; healeys@autox.team.net
Subject: Re: [Healeys] Valve clearances
I should note the rockers are pretty noisy at 0.015; IIRC I tightened them =
up just a bit.
On 1/12/2019 2:39 PM, Michael MacLean wrote:
I'd go with .016. You can always tighten it. Better loose than tight.
Mike MacLean
On Saturday, January 12, 2019, 11:01:32 AM PST, Bob Spidell <bspidell@comca=
Makes sense (for some reason). I put a DWR1 cam in my BJ8 which, according=
to DWR, 'is a little better than the BJ8 cam and so works well in any stan=
dard or mildly tuned car' but I think the 0.015" applies to all profiles on=
the spec sheet.
Bob
On 1/11/2019 8:48 PM, John Rowe wrote:
Simon,
Modified cams require the large clearance (don=92t ask me why?) So go for .=
015 that is what mine is.
John Rowe
Qld
Australia
From: Healeys [mailto:healeys-bounces@autox.team.net] On Behalf Of simon.la=
Sent: Saturday, 12 January 2019 9:14 AM
To: Healeys
Subject: [Healeys] Valve clearances
The car is a MkII BT7.
The BMC manual says adjust the clearances, cold, to 0.012=94.
Denis Welch said I should go 0.015=94, cold, after fitting their =93Fast Ro=
ad=94 cam.
The rolling road guy said 0.016=94, warm.
I have the radiator out right now so I can get a nice socket onto that nut =
and have a go at the clearances.
Stick with 0.015=94, cold?
Thanks,
Simon
--_000_DM6PR07MB453803FB848355453FEFA5A9A5870DM6PR07MB4538namp_
Content-Transfer-Encoding: quoted-printable
<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3DWindows-1=
252">
<style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo=
ttom:0;} </style>
</head>
<body dir=3D"ltr">
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
I disagree that valve clearances are not critical. As the engine comes up t=
o temperature the metal parts of the valve train (valves, lifters, push rod=
s, the head itself and the rocker shaft towers) increase in length and the =
valve clearances are calculated
to assure that this expansion isn't allowed to affect the sealing of the v=
alves on their seats. If the valves are set too tight they reach a point wh=
ere they won't touch the seats and therefore won't seal. Hot gases rushing =
through the gaps will quickly erode
the valves. Also i<span style=3D"caret-color: rgb(0, 0, 0); font-family: C=
alibri, Helvetica, sans-serif; background-color: rgb(255, 255, 255); displa=
y: inline !important">ncreasing the duration and/or lift of the cam has the=
effect of the decreasing the length
of the opening and closing ramps on the back side of the cam This reduces =
the length of time (dwell) the valve remains on the seat. Increasing the va=
lve clearance restores the dwell time the valve needs to transfer its heat =
load to the cooling system through
the valve seat and the cylinder head. Too little dwell time or the lack of=
proper valve sealing are two causes of burned valves.</span></div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
In my own experience I installed an Isky cam with a grind a little more agg=
ressive than the 100M cam and set the clearances to 0.012" per the man=
ual. Within about 2,000 miles the exhaust valves were trashed. I then took =
the time to read the Isky installation
instructions which specifically state the valve clearance needs to be set =
to 0.018". I re-installed the head with new valves and set them to Isk=
y's spec and never had another problem with burned valves.</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
Follow the cam grinder's recommendations and you will avoid trouble.</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
Bill Lawrence</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
color: rgb(0, 0, 0);">
BN1 #554</div>
<div id=3D"appendonsend"></div>
<hr style=3D"display:inline-block;width:98%" tabindex=3D"-1">
<div id=3D"divRplyFwdMsg" dir=3D"ltr"><font face=3D"Calibri, sans-serif" st=
yle=3D"font-size:11pt" color=3D"#000000"><b>From:</b> Healeys <healeys-b=
ounces@autox.team.net> on behalf of Bob Spidell <bspidell@comcast.net=
><br>
<b>Sent:</b> Saturday, January 12, 2019 11:10 PM<br>
<b>To:</b> Michael MacLean; healeys@autox.team.net<br>
<b>Subject:</b> Re: [Healeys] Valve clearances</font>
<div> </div>
</div>
<div style=3D"background-color:#FFFFFF">
<p>I should note the rockers are pretty noisy at 0.015; IIRC I tightened th=
em up just a bit.<br>
</p>
<div class=3D"x_moz-cite-prefix">On 1/12/2019 2:39 PM, Michael MacLean wrot=
e:<br>
</div>
<blockquote type=3D"cite">
<div class=3D"x_ydpe1d3e9c5yahoo-style-wrap" style=3D"font-family:times
new roman,new york,times,serif; font-size:16px">
<div>I'd go with .016. You can always tighten it. Better loose =
than tight.</div>
<div>Mike MacLean<br>
</div>
<div><br>
</div>
</div>
<div id=3D"x_yahoo_quoted_8268064185" class=3D"x_yahoo_quoted">
<div style=3D"font-family:'Helvetica Neue',Helvetica,Arial,sans-serif; font=
-size:13px; color:#26282a">
<div>On Saturday, January 12, 2019, 11:01:32 AM PST, Bob Spidell <a class=
=3D"x_moz-txt-link-rfc2396E" href=3D"mailto:bspidell@comcast.net";>
<bspidell@comcast.net></a> wrote: </div>
<div><br>
</div>
<div><br>
</div>
<div>
<div id=3D"x_yiv1110160614">
<div>
<p>Makes sense (for some reason). I put a DWR1 cam in my BJ8 which, a=
ccording to DWR, 'is a little better than the BJ8 cam and so works well in =
any standard or mildly tuned car' but I think the 0.015" applies to al=
l profiles on the spec sheet.<br clear=3D"none">
</p>
<p>Bob<br clear=3D"none">
</p>
<div class=3D"x_yiv1110160614yqt0287165987" id=3D"x_yiv1110160614yqt70378">
<div class=3D"x_yiv1110160614moz-cite-prefix">On 1/11/2019 8:48 PM, John Ro=
we wrote:<br clear=3D"none">
</div>
<blockquote type=3D"cite"></blockquote>
</div>
</div>
<div class=3D"x_yiv1110160614yqt0287165987" id=3D"x_yiv1110160614yqt92654">=
<style>
<!--
#x_yiv1110160614 #x_yiv1110160614 -- _filtered #x_yiv1110160614
{}
_filtered #x_yiv1110160614
{font-family:Calibri}
_filtered #x_yiv1110160614
{font-family:Tahoma}
#x_yiv1110160614 #x_yiv1110160614 p.x_yiv1110160614MsoNormal, #x_yiv1110160=
614 li.x_yiv1110160614MsoNormal, #x_yiv1110160614 div.x_yiv1110160614MsoNor=
mal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt}
#x_yiv1110160614 a:link, #x_yiv1110160614 span.x_yiv1110160614MsoHyperlink
{color:#0563C1;
text-decoration:underline}
#x_yiv1110160614 a:visited, #x_yiv1110160614 span.x_yiv1110160614MsoHyperli=
nkFollowed
{color:#954F72;
text-decoration:underline}
#x_yiv1110160614 span.x_yiv1110160614EmailStyle18
{color:#1F497D}
#x_yiv1110160614 .x_yiv1110160614MsoChpDefault
{font-size:10.0pt}
_filtered #x_yiv1110160614
{margin:72.0pt 72.0pt 72.0pt 72.0pt}
-->
</style>
<div>
<div class=3D"x_yiv1110160614WordSection1">
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D">Simon,<=
/span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D">Modifie=
d cams require the large clearance (don=92t ask me why?) So go for .015 tha=
t is what mine is.</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D">John Ro=
we</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D">Qld</sp=
an></p>
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D">Austral=
ia</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span style=3D"color:#1F497D"> <=
/span></p>
<div>
<div style=3D"border:none; border-top:solid #B5C4DF
1.0pt; padding:3.0pt 0cm 0cm 0cm">
<p class=3D"x_yiv1110160614MsoNormal"><b><span lang=3D"EN-US" style=3D"font=
-size:10.0pt">From:</span></b><span lang=3D"EN-US" style=3D"font-size:10.0p=
t"> Healeys [<a rel=3D"nofollow" shape=3D"rect" class=3D"x_yiv1110160614moz=
-txt-link-freetext" target=3D"_blank" href=3D"mailto:healeys-bounces@autox.=
team.net">mailto:healeys-bounces@autox.team.net</a>]
<b>On Behalf Of </b><a rel=3D"nofollow" shape=3D"rect" class=3D"x_yiv111016=
0614moz-txt-link-abbreviated" target=3D"_blank" href=3D"mailto:simon.lachla=
n@alexarevel.plus.com">simon.lachlan@alexarevel.plus.com</a><br clear=3D"no=
ne">
<b>Sent:</b> Saturday, 12 January 2019 9:14 AM<br clear=3D"none">
<b>To:</b> Healeys<br clear=3D"none">
<b>Subject:</b> [Healeys] Valve clearances</span></p>
</div>
</div>
<p class=3D"x_yiv1110160614MsoNormal"> </p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">The car is a MkI=
I BT7.</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">The BMC manual s=
ays adjust the clearances, cold, to 0.012=94.</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">Denis Welch said=
I should go 0.015=94, cold, after fitting their =93Fast Road=94 cam.</span=
></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">The rolling road=
guy said 0.016=94, warm.</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB"> </span></p=
>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">I have the radia=
tor out right now so I can get a nice socket onto that nut and have a go at=
the clearances.</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">Stick with 0.015=
=94, cold?</span></p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB"> </span></p=
>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">Thanks,</span></=
p>
<p class=3D"x_yiv1110160614MsoNormal"><span lang=3D"EN-GB">Simon</span></p>
</div>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
<div id=3D"x_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2">
<table style=3D"border-top:1px solid #D3D4DE">
<tbody>
<tr>
<td style=3D"width:55px; padding-top:13px"><br>
</td>
<td style=3D"width:470px; padding-top:12px; color:#41424e; font-size:13px; =
font-family:Arial,Helvetica,sans-serif; line-height:18px">
<br>
</td>
</tr>
</tbody>
</table>
</div>
</blockquote>
</div>
</body>
</html>
--_000_DM6PR07MB453803FB848355453FEFA5A9A5870DM6PR07MB4538namp_--
--===============6869980409328415796==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
--===============6869980409328415796==--
|