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</o:shapelayout></xml><![endif]--></head><body lang=EN-NZ link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Jim,<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>I never experienced overheating in our 997 Austin-Cooper. The sleeve fits many Minis, so I am sure it will fit you’re ‘A’ series engine too.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>The image below incorrectly says it fits a Hundred. Clearly it does not. But it DOES say it fits a <b>Sprite</b>.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Cheers<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Mark<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><img width=703 height=370 style='width:7.325in;height:3.85in' id="Picture_x0020_2" src="cid:image002.jpg@01D844F0.BDCE18B0"></span><span style='font-family:"Tahoma",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US>From:</span></b><span lang=EN-US> Jim Ryan <ryan@jimryan.com> <br><b>Sent:</b> Thursday, 31 March 2022 10:29 AM<br><b>To:</b> Mark Donaldson <ardmorebusiness@xtra.co.nz><br><b>Cc:</b> Harold Manifold <manifold@telus.net>; Healey list <Healeys@autox.team.net><br><b>Subject:</b> Re: [Healeys] Coolant bypass port in the head - 6-cyl<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>I've been following this, and just wondered if any of this would apply to a bugeye with the stock 948 in it.<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Wed, Mar 30, 2022, 4:33 PM Mark Donaldson via Healeys <<a href="mailto:healeys@autox.team.net">healeys@autox.team.net</a>> wrote:<o:p></o:p></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><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Gentlemen,</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>I had ongoing mild occasional overheating issues in my 3000 tri-carb for many years . . . until I fitted a <b>blanking sleeve</b> two years ago.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Problem instantly solved. It’ll sometimes climb to 190 on a high-speed hill climb but, otherwise, rock steady where it should be.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>The sleeve is a stock BMC part. I got mine from a local Mini supply house here in NZ. The part number is <b>11G 176</b>.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Moss sells them: 434-135. I know other suppliers do also.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>I fit it with a wax stat, which sits neatly on top.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Mark</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Ardmore</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>NZ</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'><img border=0 width=376 height=376 style='width:3.9166in;height:3.9166in' id="_x0000_i1025" src="cid:image002.jpg@01D844E2.56D6B940"></span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>From:</span></b><span lang=EN-US> Alan Seigrist <<a href="mailto:healey.nut@gmail.com" target="_blank">healey.nut@gmail.com</a>> <br><b>Sent:</b> Wednesday, 30 March 2022 2:36 PM<br><b>To:</b> Harold Manifold <<a href="mailto:manifold@telus.net" target="_blank">manifold@telus.net</a>><br><b>Cc:</b> Michael Salter <<a href="mailto:michaelsalter@gmail.com" target="_blank">michaelsalter@gmail.com</a>>; Healey list <<a href="mailto:Healeys@autox.team.net" target="_blank">Healeys@autox.team.net</a>><br><b>Subject:</b> Re: [Healeys] Coolant bypass port in the head - 6-cyl</span><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Harold -<o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thank you, now I understand how the whole thing is supposed to work. The sleeve works to cut off the bypass so that hot water is not recycled into the system after it warms up. FWIW, this only applies to the 6 cyl, the 4 cyl doesn't have any sort of bypass.<br><br>Yes, I think it would be great if you could share with us which thermostat to purchase and how to modify it.<span style='color:#1F497D'><o:p></o:p></span></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Best,<span style='color:#1F497D'><o:p></o:p></span></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Alan<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On Wed, Mar 30, 2022 at 1:28 AM Harold Manifold via Healeys <<a href="mailto:healeys@autox.team.net" target="_blank">healeys@autox.team.net</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>The coolant bypass plays an important but problematic role in the Healey’s cooling system. When the thermostat is closed coolant returns to the water pump via the bypass. See the red circle on the attached picture. The bypass is important for three reasons: its allows the coolant in the block to continue to circulate and come to a uniform temperature before the thermostat opens, it prevents hot spots that could develop from stagnant coolant and it prevents the water pump from dead heading.</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>The problematic part is in the original design the bypass was closed by a sleeve on the bellows type thermostat when the thermostat opened. The original Bellows type thermostat used a volatile liquid and were not reliable and were not suitable for the 7 psi cooling system pressure. Wax type thermostats are much more reliable but they do not have a sleeve to close off the bypass. There may be some expensive wax type replicas of the original bellows type.</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>After looking at many options the best option for a reasonably priced wax type thermostat with a sleeve to close off the bay pass is the modified Land Rover Series ll thermostat. If anyone would like to know about modifying the Landver thermostat let me know. It can be easily done.</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>Harold</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:22.8pt'><span lang=EN-US> </span><o:p></o:p></p></div></div></blockquote></div></div></div></blockquote></div></div></body></html>