throttle body coolant bypass Q

**tomcamaro97** · 06-18-2014, 12:03 PM

saw plenty of threads on the topic , but couldnt fine one to address my specific question. so it looks like most people just connect the hose coming off the coolant bypass line to the port on the top of the radiator. well my new radiator doesnt have this port. my plan was to just pull the line that is coming off the bypass tube and cap it.. and cap both sides of the throttle body as well, for looks.

any adverse effects of capping this line off the bypass tube? i couldnt see any , but figured doesnt hurt to ask.

**Firebirdjones** · 06-18-2014, 12:19 PM

Originally Posted by tomcamaro97

saw plenty of threads on the topic , but couldnt fine one to address my specific question. so it looks like most people just connect the hose coming off the coolant bypass line to the port on the top of the radiator. well my new radiator doesnt have this port. my plan was to just pull the line that is coming off the bypass tube and cap it.. and cap both sides of the throttle body as well, for looks.

any adverse effects of capping this line off the bypass tube? i couldnt see any , but figured doesnt hurt to ask.

That's your steam vent. You need it. I'd take that radiator back for a correct one or you'll be looking at other ways to tap into the cooling system.

On retro swaps I make a connection/fitting on the upper radiator hose. The idea is to have it connected higher than the engine itself (top of the radiator) There are some that also drill and tap the top of the water pump. Not fond of that idea but it's a solution.

**tomcamaro97** · 06-18-2014, 12:30 PM

it is a retro swap. so the radiator isnt the problem. yeah i knew it was a steam vent, just didnt realize that needed to be plumbed back to the radiator side of the system. ugh.. i really didnt want to have it connected, cluttering up my nice clean engine bay..

if that is correct and it must be plumbed to the upper side of the collant system i guess i could probably plumb it into the upper radiator hose some how like you suggest.. although that is still lower than the throttle body itself. ill have to figure out a way to T a 3/8 hose into a 1.5in hose. any suggestions? does it matter where on the upper radiator hose i plub it to? if i keep it near the engine i can keep it hidden.

**Firebirdjones** · 06-18-2014, 12:43 PM

It doesn't need to be higher than the throttle body, just higher than the cooling system. The thought process I believe is to be higher than where the thermostat is, which is rather low on an LS engine.

My personal experience is that I like to use the upper radiator hose somewhere at it's highest point. If you drill and tap the water pump, then you're stuck doing that on the next pump, and the next one, etc...and would make a road side water pump replacement a real pain in the ass.

Soo, I simply find a convenient spot to cut the upper hose where I can splice in a simple 3" long pipe of the same diameter. I use cast iron pipe from the hardware store because it's thicker for drilling and tapping (I get more threads in it that way) You could probably substitute most anything here that you are comfortable with though.
Then I tap for pipe thread, screw in a 90 degree elbow of the size you need and connect your hose. I use the 90 degree elbow so I can run the steam line tight along the bottom of the radiator hose and keep it out of sight. You just simply clock your spliced in pipe in a position that is convenient to hide the steam hose.

It's simple and easy.

**tomcamaro97** · 06-18-2014, 12:53 PM

thanks firebird.. my pipe already had a 1.5in wide aluminum elbow on it where i had to connect two hoses, so ill just try and find a bulkhead fitting to run the steam pipe to it as its very thin and no chance of tapping, its about 3 inches below the top of the radiator, but still well above the t-stat.. im sure my local racing shop will have something i can make work.

just one more thing from the never ending swap... ugh... never though ide loose steam on this swap.. but im starting to get there.. just gotta tell myself its almost done..