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1275 bypass hose????

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paulsherman

Jedi Trainee
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Me again, this time a question about the bypass hose. The head I installed on my 1275 has the fitting where the bypass hose should be connected, has a plug, rather than the fitting for the hose. What is the best solution, replace it with the fitting for the hose or just plug the other end at the water pump, or ----?

Thank you
 
Plug the water pump end. The thermostat that the bypass system was supposed to work with is NOA or very expensive[ I believe someone is making them again]. The purpose was to speed engine warm up and I don't believe many spridgeteer's need that now days anyway.

Kurt
 
I am not familiar with the t-stat that Nomad mentioned. It is my understanding that the setup goes the other way.... that if you don't use the bypass (as was common on later A+ engines) you need to drill a few holes in the T-stat to circulate water properly in/around the head before the t-stat opens.

For a general discussion/argument on the t-stat and bypass system, see the thread linked below.
https://www.mmoc.org.uk/viewtopic.php?f=4&t=46241
 
Block it up and never worry again. Been building A series motors since 1968, and, have always blocked off the bypass, rather than risk a hose failure.

It works fine and, affects nothing. No need to drill holes in the T Stat.
 
dklawson said:
I am not familiar with the t-stat that Nomad mentioned. It is my understanding that the setup goes the other way.... that if you don't use the bypass (as was common on later A+ engines) you need to drill a few holes in the T-stat to circulate water properly in/around the head before the t-stat opens.

For a general discussion/argument on the t-stat and bypass system, see the thread linked below.
https://www.mmoc.org.uk/viewtopic.php?f=4&t=46241
Click to expand...

Doug, i agree that if your T stat does not have the little valve nest to the thermo activated part then you need to drill a hole so that air doesn't get trapped in the head on start up. For more info on the original T stat check out what Barney Gaylord has on it in MGA GURU.

Kurt.
 
I expect the original Spridget t-stat was the same idea as the XK140 which also had a similar bypass. The stat had a skirt that moved as it opened to cover the bypass so that all heated water went back to the radiator. The typical solution was to plug the hole but the plug still needs a smaller hole through it or you get the trapped air problem.
 
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