Coolant hoses on throttle/Idle valve

[paradox616]

Does anyone know what the coolant hoses that pass through the throttle and idle valve do? is it some kind of emission requirement? or maybe to prevent parts from seizing up in extreme cold?

im relocating my throttle body as a front facing manifold and was considering not connecting them up (wont be a big issue if i do or don't)

 

[jdub]

They are there to heat the TB/ISCV to prevent intake icing under certain OAT/humidity conditions. It does not have to be below freezing outside to meet these conditions either

In most warm climates you can do away with them without a problem.

 

[paradox616]

i come from the land down under it never snows anywhere except on a mountian's here,

Lowest it gets is 5deg celcius and this isnt a daily driver anyway only a weekender so usual temp is 17-25deg C

should give me less heat soak in the throttle at least

cheers for that!

 

[hvyman]

bypass that shit

 

[jdub]

Here's a chart that shows when intake icing is most likely...yes, it's an aircraft engine, carburetor icing chart. Works exactly the same for an earth bound motor with a TB though:

If you live in a climate where the humidity/temp conditions are in the orange, green, or blue bands you might want to keep the coolant hoses...definitely in the blue or green. Like I said, it does not have to be freezing outside or freezing precipitation (snow, sleet, etc) for intake icing to form. For example, at +20 deg C OAT, +10 deg C dewpoint (~50% humidity) puts the engine well in the green zone for moderate icing at cruise (steady state RPM) and serious icing at idle RPM.

bypass that shit

You do not want to "bypass that shit" without thinking about it. The good news is all that will happen is the engine will run like crap and perhaps strand you on the roadside for a bit till the ice melts...while you scratch your head and blame it on "the crappy 7M". Different story on an airplane...there's been a lot of smoking holes from this happening to airplane engines.

 

[paradox616]

to be honest id say we fall outside the effected area, all local cars produced her are not fitted with coolant that passes through throttles. IJ lives in the same part of Aus as me, maybe he'd know!

this is a weekender anyway so chances are if it was cold enough that ice is forming id rather be inside with a heater watching tv ill see how hard it is to retain once i get my manifold back, i was thinking along the lines of heat soak into the throttle, why introduce heat if its not needed... ill see when i get the manifold back