water flow in head when thermostat closed

S0LJAH · Post by **S0LJAH** » Mon Apr 27, 2009 4:33 am

hey guys

how does the water flow around a stock 4g63 when the thermostat is closed?
does one of the four water pipes coming out of the thermostat housing allow water to bypass it back into the rear of the water pump when the thermostat is closed?but the thermostat opening off blocks this bypass making the water flow through to the radiator

or does a turbo motor simply get its flow from the water going out of the pipethermo housing and through the turbo?

at the moment my car has the heater pipe from the thermostat housing (largest one of the four) running directly into the water pump through the rear bypass pipe (RWD water pump)

good when the eninge is cold as the water just flows around the block (and i dont end up with still water in my long pipe to my remote mounted thermostat) but i think this is just pumping a whole lot of hot water back into the engine and when i push it for a steady period it overheats

i want to block this off so i can see if it helps but as im not running water cooling (all my other thermostat housing water lines are blocked off)

i am wondering how water will flow to allow warm water to reach the thermostat?

Bill Hincher · Post by **Bill Hincher** » Mon Apr 27, 2009 11:35 am

usually through the heater core but when the heat valve is closed, it uses a by pass hose

S0LJAH · Post by **S0LJAH** » Tue Apr 28, 2009 1:29 am

ok so is the 4g63 bypass the second hole behind the waterpump on the block?

this one here

Bill Hincher · Post by **Bill Hincher** » Tue Apr 28, 2009 8:11 am

Bill Hincher · Post by **Bill Hincher** » Tue Apr 28, 2009 8:11 am

citrus3000psi · Post by **citrus3000psi** » Tue Apr 28, 2009 1:22 pm

Hopefully I'm saying this right...

The bypass is the metal tube that goes underneight the exhaust manifold. There is a suction on this pipe not pressure. So this sucks coolant through the heatercore and the heatercore should be connected to the high pressure side just below the thermostat.

Bill Hincher · Post by **Bill Hincher** » Tue Apr 28, 2009 1:55 pm

the water pumps are all the same but the enterance ports are different, the Mitsubishi water pump pulls water up from the side inlet where the metal pipe joins at the lower radiator hose and drives coolant from its center back into the block

the second hole in the block behind the water pump allows coolant to pass on both side of the cylinder walls

better systems pull into the center of the pump and pushes out the side out let, you can mostly tell by the location of the inlet hole, whether is in front or in the rear of the pumps drive gear

because the water pump is a centrifical force system, there is no positive pressure so the coolant does not force its way past the thermostate, that is the way the old v-8's were and that is why you had to wait until the thermostate opened before the heater would work in the car, the water pump was just pushing against a dead curcuit until the engine warmed up, but on the newer cars, coolant is bypassed though the heater core and or bypass hose while the thermostate is closed and you get inside heat instantly from the engine block

S0LJAH · Post by **S0LJAH** » Wed Apr 29, 2009 12:46 am

so my pump is just "free wheeling" in the water till the thermo opens?
i.e it doesnt build up pressure and the water just sits stagnant in the block

heres what i found else where, which agress with what you say on the other hole allowing coolant to the other sides of cylinder, but says that the hole acts as a bypass too when the thermo is closed

Underneath the water pump, the block has a second small hole on the firewall side that allows a little bit of water back into the pump - when the thermostat is open, this helps circulate coolant to that side of the cylinder sleeves before it goes out to the radiator.

When the thermostat is closed, it causes coolant to just recycle around the block, in addition to the flow through the heater core, throttle body and the oil/water cooler.

basically what i need to know bill is if i block off

other waterline and just have my lower rad pipe going to the waterpump then have my water pipe exiting from the rear of the head going through my thermostat housing to the top rad pipe is it going to work?

Hopefully I'm saying this right...

The bypass is the metal tube that goes underneight the exhaust manifold. There is a suction on this pipe not pressure. So this sucks coolant through the heatercore and the heatercore should be connected to the high pressure side just below the thermostat.

yea im well aware of what that pipe does, thats not the sort of byass im talking about, it is simply the way the heater is hooked up, you turn the heater off you have no flow
im talking about a bypass which is ussually open when the thermostat is closed and the as the thermostat opens it restricts flow to the bypass hole

my car is hooked up like this (heater core thermostat housing outlet to back of water pump) at the moment but minus a heater core its just looped back in and i think it is giving me cooling problems when the car is up to temp and getting thrashed around, so i want to eliminate this loop but dont want to lose my water flow when the thermo is closed

AyeZer · Post by **AyeZer** » Sat Dec 12, 2009 10:01 pm

Making a bypass or shortcut hose is not working in my thermostat. What is the problem with it? I think the things that I have done have some mischief and failures.

_________________
Refrigerator Water Filter

Bill Hincher · Post by **Bill Hincher** » Sun Dec 13, 2009 8:57 am

Bill Hincher · Post by **Bill Hincher** » Wed May 11, 2011 6:11 am

Post by **AustinTSI** » Fri Oct 14, 2011 4:22 pm

Check out the item at the bottom of this page. It is a 1 1/4" Hose to 1 1/4" Hose with Closeable 1 1/4" bypass port custom thermo valve like what Bill mentions.

http://www.ipsco.org/Custom%20Services/ ... custom.htm