Thermostat bypass question

[turbosax2]

From the factory, our cars have three ways to bypass coolant around the thermostat when it is closed:
1. Turbo
2. Heater core
3. Oil cooler

What I want to know is how much volume is needed to safely bypass the thermostat while it is closed? Currently, I'm running a 2g thermostat housing / water pipe setup and I'm only using the turbo and a slight gap between the thermostat and the housing to bypass coolant:
http://www.dsmtuners.com/forums/151705738-post245.html

I haven't noticed any issues with this setup, but haven't raced my car either.


My brother is currently running a 1g thermostat housing / water pipe setup. We looped the heater core lines on his car to make sure the coolant could bypass the thermostat. We will soon be removing the factory oil cooler from his car so he'll lose that bypass loop. What I'm wondering is if we can safely remove the heater core loop as well and just rely on the turbo loop for bypassing the thermostat? Perhaps drilling a couple of holes in the thermostat would be beneficial to help coolant bypass in this case?

The potential problem I can think of is if not enough coolant is bypassed, the water pump could could suck an air pocket or have to try to push through too much resistance and break. Pros include less hardware in the car and potentially better cooling if more coolant goes through the radiator rather than bypassing it once the thermostat is open. Eventually we could even get rid of the water pipe completely (with a custom radiator of course).

I'm just kind of thinking aloud here and would love to hear anyone's experience in matters like this.

 

[sniver]

I cannot speak from much experience with our cars, however I do have some experience with other cars. We put together a a camaro, with no bypass other than the 1/8 in hole in the thermostat. Haven't had any issue with it.

I see no issue with it, most older chevy's have a vacuum valve on the coolant inlet to the heater core. when closed, there is virtually no bypass to them.

You could try it and just listen to it, do the dowel/stethoscope trick and listen. A cavitating pump of any kind is very easy to hear. I know when a well pump cavitates, its noticeable, it kinda free-spins/sounds like a garbage disposal.

Also I bet our cheap stamped impellers cavitate near redline, its a rpm related issue, more than it is a bypass amount. I was reading around after posting this, and it seems a no bypass could make the fluid "stall" but its not damaging like pump cavitation.

 

[3kgt2nv]

very interested in this as Im about to hack off the small pipe on my water pipe that goes to the heater core since the heater core is being removed.

 

[sniver]

Upon some more thinking, I guess another concern I overlooked was how the coolant pressure in the block would rise. No pressure bleed could result in coolant leaks, maybe a few holes in the thermostat wouldn't be such a bad idea after all. I'd hate to blow a water pump gasket, that would be unwelcome.

 

[3kgt2nv]

this is what i have in mind. its an easy solution and should look clean when finished

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[gofer]

Eric, the TB FIAV would be a t-stat bypass as well and to do it requires a small section of hose that doesn't look goofy and its easy to keep from leaking. Currently I've got my TB FIAV lines, heater core lines, and OFH lines wrapped but if I could figure out a good way to plug them I would. How do you plan on plugging them?

If it were me I'd leave the TB FIAV lines wrapped to bypass the t-stat and then plug everything else up, if you can figure out how?

 

[3kgt2nv]

I have my fiav lines deleted so for me I think the one hose to the water pipe is how im going to have to go. I also think since im going to loose my feed for my turbo till I get a non water fed turbo Ill put a fitting in one of the t stat housing holes to also help bypass it.

 

[turbosax2]

sniver, thanks for the input!

3kgt2nv, that's basically how we have my brother's car setup now (without shortening the water pipe), I'm just trying to eliminate that line completely if possible. Just as a tip, to prevent that hose from kinking we had to use a SS spring inside of it.

Corey, the FIAV hoses have been long gone. Anytime we have removed a loop (oil cooler, FIAV, or heater) we remove the portion of the water pipe leading to those hoses and weld it up. It's the only way I feel comfortable doing it.

Really, this train of thought stemmed from me trying to figure out ways to get rid of the stock water pipe, it's just a stupid piece. In the future I would like to have a radiator with the lower hose on the driver side so it can be a straight shot to the water pump. With the inlet and outlet on opposite sides of the radiator it should provide superior cooling. From there my train of thought went to what we can do now without having a custom radiator.