<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:"Courier New";}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style></head><body lang=EN-AU link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal>...you’re really not going to do any harm tapping the mounting holes. Just use the smallest diameter that you can to thread the existing holes. The alloy is no softer than eg an aluminium sump as per MG T type, which have tapped holes where the bolts do have to be done up tightly. And you’re not (I assume) going to be taking the filters on and off every 5 minutes! I think the reduction in aggravation when you do have to remove them is well worth it!<br><br>Cheers</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Peter Linn</p><p class=MsoNormal>Brisbane Oz</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Austin Healey 100 V6</p><p class=MsoNormal>MG TC/Q type replica</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows 10</p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='border:none;padding:0cm'><b>From: </b><a href="mailto:michael.salter@gmail.com">Michael Salter</a><br><b>Sent: </b>Friday, 23 November 2018 6:47 AM<br><b>Cc: </b><a href="mailto:healeys@autox.team.net">healeys@autox.team.net</a><br><b>Subject: </b>Re: [Healeys] Tapping SUs for air filters.</p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Better still get some of these:</p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><a href="https://mossmotors.com/bracket-rear-air-cleaner?assoc=19384">https://mossmotors.com/bracket-rear-air-cleaner?assoc=19384</a></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, Nov 22, 2018, 12:48 PM Bob Spidell <<a href="mailto:bspidell@comcast.net">bspidell@comcast.net</a> wrote:</p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><p>I've not tried this, but my first thought is that the aluminium bodies of the SUs would be too soft; eventually, you might strip the threads (esp. if trying to get a good seal with the filter). Why not do what you're likely to end up doing anyway: installing thread inserts (Helicoil or similar). I think 5/16" bolts would be sufficient.</p><p>Bob</p><div><p class=MsoNormal>On 11/22/2018 6:15 AM, <a href="mailto:simon.lachlan@alexarevel.plus.com" target="_blank">simon.lachlan@alexarevel.plus.com</a> wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I’ll be removing my carbs soon in order to achieve clearance for raising (the front of) the engine. (Harmonic balancer installation).</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>So, it struck me that I may give my 3 HD6s another go. Swap them with the current setup.</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thinking it through and looking at the big box of bits, I recalled what a pain it is to get the nuts and two washers onto the bolts that hold on the air filters. I have French manufactured K&N lookalikes. The bolt starts inside the filter, goes through the carb and gets two washers and a nut. Very awkward to deal with those nuts and washers. PITA.</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I thought that I might put in helicoils then I thought “Why not tap the holes?”</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The holes on my HD6s are 11/32” or 8.8mm.</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I am no engineer but it seems to me, from looking at tables on Google, that I could use a 25/64” drill bit and tap them out to 7/16”. I have both the drill and the tap but would like some expertise applied to the issue before I start drilling.</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Any input would be much appreciated.</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thanks,</p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Simon</p></div><p class=MsoNormal><o:p> </o:p></p></blockquote></div></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>