heater core bypass

[TaylorRacing]

Alright i have been searching for a long time and have still yet to come across the information i am looking for. I have the repair manual and it still isnt giving me a good enough diagram of what i am after. I will not be running a heater core. My choice and the arguments about just leave it there are getting tiring as that is not an option.

Now, i see the lines running from the back of the water pump housing under the exhaust manifold. and from what i can see both those lines are feeding from the heater core to the the water pump housing. But where i am not 100% sure in the "nipple" on the back of the head. I am going to assume, takes coolant from the back of the head and joins the lines feeding back to the water pump housing..


Assuming i am understanding the system correctly all would need to do is fit an elbow where the "Nipple" is and feed in back into one of the runners going under the exhaust manifold?

And on the opposite side of the block the coolant enters the intake manifold then joins the other runner going back to the water pump housing. I am nearing the end of my swap and need to make this as simple and "bullet" proof as possible.

Does anyone here have experience with what i am trying to do?

this is the online diagram i have been referencing but as it is the internet i am open to this having the wrong information so please will someone help me get this taken care of My motor is out of a 89 Turbo

thanks!


-Mike

 

[toyotanos]

The metal pipes need to stay so your engine has coolant flow through it, as do all the fittings they plug into. The only thing you need bypass is the heater core hookups.

I see two options based on the way the factory heater system works.

1- Loop the circuit from banjo bolt fitting to return fitting to simulate an open heater core valve (less the restriction through the core)
2- Cap both nipples to simulate the valve being closed.

I did a hybrid of both since there is a small amount of leakage through every water control valve I've had my hands on. I looped the pipe, but put a restriction into it so it flows slowly.

There may be a better way, but from a functional standpoint, this matches the function of a factory system as closely as I could think of at the time.

 

[TaylorRacing]

so where the banjo bolt is on the back of the head. i would just "cap" it off.. Which i see in theory would work but i am skeptical at the idea of possible failure from it shaking loose or the cap failing. i aslo see how just looping it over could work as well. any idea who would make such a hose? Seems to me that a loop over would be best bet for reliability sake. Thanks for the fast response! now how to accomplish this.. hmm...


-Mike

 

[toyotanos]

I just grabbed some heater hose from the parts store and forced it on (5/8" hose is slightly too small, but seals great with some install effort) It's OK if the hose kinks because you don't want full flow anyways.

 

[CyFi6]

so where the banjo bolt is on the back of the head. i would just "cap" it off.. Which i see in theory would work but i am skeptical at the idea of possible failure from it shaking loose or the cap failing. i aslo see how just looping it over could work as well. any idea who would make such a hose? Seems to me that a loop over would be best bet for reliability sake. Thanks for the fast response! now how to accomplish this.. hmm...


-Mike

Cap the banjo at the back of the head and the fitting under the intake manifold at the rear of the engine. Use clamps to keep them secured, would be just as reliable as a looped hose.

 

[TaylorRacing]

think a basic auto parts store would carry rubber caps? home depot? Thanks for the help guys really do appreciate it!


-Mike

 

[super51fan]

To get one that fits properly go to the toyota dealer. I know the 89' turbo supra has a rubber cap on the heater pipe below exhaust manifold. My 92 does not have this plug anymore. This way you have a properly made rubber cap for the intended job. Plus it will fit the pipes in question.

 

[CyFi6]

^+1 and they are cheap.
http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=1603&P=1

Cap part number 90339-16001
Clamp part number 96112-10250

 

[TaylorRacing]

Life Saver!! I will be calling the dealer tomorrow. was thinking about buy new pipes as well for piece of mind. thank you for the help guys! One step closer to hearing this thing run!


-Mike