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--></style></head><body lang=EN-US link=blue vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>The blanking sleeve was available for Healey’s and is listed in the parts list with this note: “Sleeve - thermostat blanking 11G 176 b For use in extremely hot climates in lieu of thermostat, optional extra”. I don’t think it is a good idea to use the blanking sleeve and a thermostat. The blanking sleeve will fit any car that uses a standard 2 1/8” thermostat.</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Pictures of the modified Land Rover 596225 thermostat are attached. Remove the upper lip from the original thermostat with a Dremel cutting disk. The material is soft brass and cuts easily. The original in the open and closed position is on the left and the modified is on the right. The other picture is the modified thermostat in a Healey 3000 cylinder head.</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Harold<o:p></o:p></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:ardmorebusiness@xtra.co.nz">Mark Donaldson</a><br><b>Sent: </b>Wednesday, March 30, 2022 3:16 PM<br><b>To: </b><a href="mailto:ryan@jimryan.com">Jim Ryan</a><br><b>Cc: </b><a href="mailto:manifold@telus.net">Harold Manifold</a>; <a href="mailto:Healeys@autox.team.net">Healey list</a><br><b>Subject: </b>RE: [Healeys] Coolant bypass port in the head - 6-cyl</p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'>Jim,</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'>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.</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'>The image below incorrectly says it fits a Hundred. Clearly it does not. But it DOES say it fits a <b>Sprite</b>.</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'>Cheers</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'>Mark</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-family:"Tahoma",sans-serif;color:#1F497D'><img border=0 width=703 height=370 style='width:7.3229in;height:3.8541in' id="Picture_x0020_3" src="cid:image001.jpg@01D84458.2B40D6B0"></span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> 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<span lang=EN-NZ><o:p></o:p></span></p></div><p class=MsoNormal><span lang=EN-NZ> <o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-NZ>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></span></p></div><p class=MsoNormal><span lang=EN-NZ> <o:p></o:p></span></p><div><div><p class=MsoNormal><span lang=EN-NZ>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></span></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Gentlemen,</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ 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><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ 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><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ 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><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Moss sells them: 434-135. I know other suppliers do also.</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>I fit it with a wax stat, which sits neatly on top.</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'> </span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Mark</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>Ardmore</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='font-size:10.0pt;font-family:"Tahoma",sans-serif'>NZ</span><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ 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><span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ style='color:#1F497D'> </span><span lang=EN-NZ><o:p></o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><b>From:</b> Alan Seigrist <<a href="mailto:healey.nut@gmail.com">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">manifold@telus.net</a>><br><b>Cc:</b> Michael Salter <<a href="mailto:michaelsalter@gmail.com">michaelsalter@gmail.com</a>>; Healey list <<a href="mailto:Healeys@autox.team.net">Healeys@autox.team.net</a>><br><b>Subject:</b> Re: [Healeys] Coolant bypass port in the head - 6-cyl<span lang=EN-NZ><o:p></o:p></span></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ> <o:p></o:p></span></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ>Harold -<o:p></o:p></span></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ> <o:p></o:p></span></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ>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.<o:p></o:p></span></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ>Best,<o:p></o:p></span></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ>Alan<o:p></o:p></span></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ> <o:p></o:p></span></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:4.8pt'><span lang=EN-NZ>On Wed, Mar 30, 2022 at 1:28 AM Harold Manifold via Healeys <<a href="mailto:healeys@autox.team.net">healeys@autox.team.net</a>> wrote:<o:p></o:p></span></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:9.6pt'>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 lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:9.6pt'>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 lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:9.6pt'>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 lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:9.6pt'>Harold<span lang=EN-NZ><o:p></o:p></span></p></div></div></blockquote></div></div></div></blockquote></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.45in'> <span lang=EN-NZ><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>