Radiator / thermostat

[freddie558]

Hi,

I have a '99 Hayabusa engine in the back of my Isetta. I have had problems with heat and the radiator blowing out all the coolant. I have partially solved this by fitting an expansion bottle from a Renault 10 which has a pressure cap on the top. I am about to have a new rad made and my question is: What is the purpose of the small pipe which goes from the top of the radiator to the top of the thermostat housing? I am tempted to remove the thermostat altogether, if I do this, do I still need that small pipe?

Thank you for your answers.

Fred Parker (UK)

[jwcfbd]

The only thing I could find is in the parts book.  The list that hose as a water bypass line.  I'm just guessing but I would say it allows the antifreeze to flow if the thermostat fails in the shut position.  It may also be to make sure there is no trapped air in the system.  Hopefully someone here actually knows for sure.



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[BA BUSA]

Hi,

I have a '99 Hayabusa engine in the back of my Isetta. I have had problems with heat and the radiator blowing out all the coolant. I have partially solved this by fitting an expansion bottle from a Renault 10 which has a pressure cap on the top. I am about to have a new rad made and my question is: What is the purpose of the small pipe which goes from the top of the radiator to the top of the thermostat housing? I am tempted to remove the thermostat altogether, if I do this, do I still need that small pipe?

Thank you for your answers.

Fred Parker (UK)

Don't remove the thermostat...upgrade your radiator and fan(s).

Without a thermostat the coolant will circulate too fast and overheat...doesn't stay in the radiator long enough to cool off

[missilelike]

Hi,

I have a '99 Hayabusa engine in the back of my Isetta. I have had problems with heat and the radiator blowing out all the coolant. I have partially solved this by fitting an expansion bottle from a Renault 10 which has a pressure cap on the top. I am about to have a new rad made and my question is: What is the purpose of the small pipe which goes from the top of the radiator to the top of the thermostat housing? I am tempted to remove the thermostat altogether, if I do this, do I still need that small pipe?

Thank you for your answers.

Fred Parker (UK)

Don't remove the thermostat...upgrade your radiator and fan(s).

Without a thermostat the coolant will circulate too fast and overheat...doesn't stay in the radiator long enough to cool off

+1

[omslaw]

LOL. I just got done reassembling my motor after replacing the head gasket. I was wondering the same thing about that hose!

Seems like an awfully small diameter for a bypass...