<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><!--
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--></style></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal>OK I got confused on this exchanged. Regarding the UNF threads, my info shows the 3/8 (major diameter) UNF bolt as having 24 threads per inch. The exchange mentioned 20 TPI</p><p class=MsoNormal>Perry</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 0in 0in 0in'><p class=MsoNormal style='border:none;padding:0in'><b>From: </b><a href="mailto:michaelsalter@gmail.com">Michael Salter</a><br><b>Subject: </b>Re: [Healeys] Motor Mout Bolts</p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><b><i><span style='font-size:12.0pt;font-family:"Comic Sans MS"'>"So, now I can run a 3/8 - 20 UNF tap through the hole to clean it up. So, I take it all threaded holes in the engine bay are UNF."</span></i></b><span style='font-size:12.0pt;font-family:"Comic Sans MS"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Comic Sans MS"'>I think that may be a stretch Mike ... I know, for example, that the nuts welded into the frame for the battery hold down rods changed from BSF to UNF as C.#156839. I would bet that there are other instances of this.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Comic Sans MS"'>I would always recommend checking your parts book for the correct thread for your car before running a tap through any.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Comic Sans MS"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Comic Sans MS"'>M<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sun, May 10, 2020 at 12:50 PM Michael MacLean <<a href="mailto:rrengineer.mike@att.net">rrengineer.mike@att.net</a>> wrote:</p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><p class=MsoNormal>The only reason I asked this question in the first place was because a 3/8" UNF bolt screwed into all eight holes for a few threads and stopped. Because it was the same in all eight holes I did not want to force it. So, now I can run a 3/8 - 20 UNF tap through the hole to clean it up. So, I take it all threaded holes in the engine bay are UNF. Certainly simplifies it.</p><div id="gmail-m_-5974905000147687713yMail_cursorElementTracker_1589129381257"><p class=MsoNormal style='margin-bottom:12.0pt'>Mike MacLean</p><blockquote style='margin-left:0in;margin-right:0in;margin-bottom:15.0pt'><div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif;color:#6D00F6'>On Sun, May 10, 2020 at 8:51 AM, Curtis Arndt<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif;color:#6D00F6'><<a href="mailto:cnaarndt@gmail.com" target="_blank">cnaarndt@gmail.com</a>> wrote:<o:p></o:p></span></p></div></div><div style='border:none;border-left:solid #6D00F6 1.0pt;padding:0in 0in 0in 15.0pt;margin-top:7.5pt'><div id="gmail-m_-5974905000147687713yiv7438463404"><div><p class=MsoNormal>They are UNF on my BN1 built 11 Jan. '55. If they ever were BSF, it was very early in BN1 production. <o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Sat, May 9, 2020, 16:54 Perry via Healeys <<a href="mailto:healeys@autox.team.net" target="_blank">healeys@autox.team.net</a>> wrote:</p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><p>Michael</p><p>There was a slow switch from BSF to UNF fasteners used and threads on some parts starting about mid 1954 through the end of 1955 at several locations on the 100. However I can not speak to the engine mount to chassis fasteners. </p><p>Its one of those areas of the car that if I ended up with damage to the welded nut threads that could not be cleaned up with a tap I would do what was necessary to secure the engine mount short of replacing the welded nut. </p><p>Perry</p><p> </p><div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:currentcolor currentcolor'><p><b>From: </b><a href="mailto:rrengineer.mike@att.net" target="_blank">Michael MacLean</a><br><br></p></div><p> </p><p>Are the bolts that fasten the motor mounts to the frame different threads between the BN1 and the BN2?</p><div id="gmail-m_-5974905000147687713yiv7438463404m_8389926694834509769yMail_cursorElementTracker_1589058832618"><p style='margin-bottom:12.0pt'>Mike MacLean</p></div></div></div></blockquote></div></div></div></blockquote></div></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>