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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Thermostat Bypass Sleeve

Has anybody had ay experence with this part that Moss sells. I have a car that heats up in traffic and I have the Fan Schroud on it and it still heats up when in traffic. In the catalog it claims that it is for racing but I am wondering how it would do in traffic.
GK George

It simply replaces the thermostat, so you have no low temperature limit.
Art Pearse

George, I use the blanking sleeve in conjunction with a thermostat as well as the fan shroud and have no problem with the overheating.

The B series engine has a bypass port at the water outlet which allows coolant to circulate back into the block without going through the radiator. This design is usefull in helping the engine get up to operating temparature a bit quicker.

The original thermostats for these cars were a sleeved type. When the thermostat opened, the sleeve would close off the bypass port and force the coolant to be routed through the radiator. Modern thermostats do not have such a sleeve and so, even when the thermostat is open, some of the coolant is able to flow through the bypass port back into the block without going through the radiator. Using the bypass sleeve effectively closes off the bypass port so that all the coolant must flow through the radiator, giving it a chance to cool off a bit in the process.

Barney has a more information about this on the mgaguru site.

Just like anything else, a blanking sleeve is not a magic bullet in and of itself, but I believe it is a useful part of the cooling system as a whole.
Andy Bounsall

I would recommend the thermostat with the built-in blanking sleeve. As the prior post, it is not the magic bullet, but the combination does well.

http://www.mossmotors.com/Shop/MoreInfo.aspx?PlateDetailID=587393&LanguageID=1

Devin

GK,
Most MGA overheating problems can be traced to incorrect timing, or the mixture being too weak (lean). A 7lb radiator cap is specified, and some MGA's run at 212 degrees quite happyly (this is not overly hot).
Peter.
P. Tilbury

This thread was discussed on 25/06/2009

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.