4x4 Rock Buggy TC 2.4 Build
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12-15-2015, 12:45 PM
#79
Junior Member
Thread Starter
In the above image the small rectangular coolant port on the back of the block is the coolant outlet from the pump to what used to be the oil cooler and heater core, both of which are deleted now. I plan to create a small block-off plate with an AN fitting welded to it that will be the new coolant supply line for my turbo. The outlet for the turbo will tee into the larger pump supply line going into the back of the water pump at the front of the engine. Does this sound logical?
The oil return line going from the turbo to the oil pan is straight forward, I will simply weld a bung into the pan for that. What is the best source for the oil going to the turbo though? I assume one of the many fittings on the side of the block?
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patooyee (12-15-2015)
12-15-2015, 07:58 PM
#85
Junior Member
Thread Starter
Anyone happen to know the thread specs on the turbo coolant and oil fittings? I'm reading from other k03 / 04 applications the coolant fittings are m14x1.5 and the oil inlet is m12x1.5. No clue if that is true of the Chevy k04 ...
Last edited by patooyee; 12-15-2015 at 08:32 PM.
12-16-2015, 03:56 PM
#87
Junior Member
Thread Starter
I noticed in this thread that Axelthered05 appeared to tap the drain plug hole in the water pump housing for his return coolant fitting so I did tat as well.
https://www.cobaltss.net/forums/how-...nstall-287173/
https://www.cobaltss.net/forums/how-...nstall-287173/
12-16-2015, 04:06 PM
#88
i dont really see the point in taping a hole thats already threaded. i just bought a barbed fitting that fit the pump drain thread size. But im pretty sure that would be your coolant feed and the thermostat housing is where it returns.
12-16-2015, 04:22 PM
#89
Junior Member
Thread Starter
Meh ... it's tapped 1/4 NPT now. 
I'm sure whatever metric thread it was was a PITA to find adapters to AN for so now it's something common at least.
I believe you are wrong about it being a supply though. Coolant comes in the t-stat, through the t-stat housing and coolant pipe into the back of the water pump. It goes into the engine via a passageway that is cast into the block and not visible with the water pump still attached. (I'll post a pic of it later.) Inside the block it tees off into at least 2 directions that I am aware of. One passage circulates it through the engine and up to the head where it exits via the hose fitting there. The other passage at the pump circulates it back to the rectangular port in the back of the engine tat I posted a pic of earlier. There is a separate cavity in the t-stat housing for the rectangular port which feeds the heater core and then the return from the heater core goes back into the other pipe in the back of the t-stat housing to be returned back to the back side of the pump.
EDIT: Hmmm ... I think I may be wrong. Alldata's description is confusing. Kind of why I asked before. Now I need to do some more research ... Here is what Alldata says:
"Coolant flows from the radiator outlet and into the water pump inlet. Some coolant flows from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost capability as the coolant warms up.
Coolant also flows from the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.
The coolant then flows through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.
From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed."
I'm sure whatever metric thread it was was a PITA to find adapters to AN for so now it's something common at least.I believe you are wrong about it being a supply though. Coolant comes in the t-stat, through the t-stat housing and coolant pipe into the back of the water pump. It goes into the engine via a passageway that is cast into the block and not visible with the water pump still attached. (I'll post a pic of it later.) Inside the block it tees off into at least 2 directions that I am aware of. One passage circulates it through the engine and up to the head where it exits via the hose fitting there. The other passage at the pump circulates it back to the rectangular port in the back of the engine tat I posted a pic of earlier. There is a separate cavity in the t-stat housing for the rectangular port which feeds the heater core and then the return from the heater core goes back into the other pipe in the back of the t-stat housing to be returned back to the back side of the pump.
EDIT: Hmmm ... I think I may be wrong. Alldata's description is confusing. Kind of why I asked before. Now I need to do some more research ... Here is what Alldata says:
"Coolant flows from the radiator outlet and into the water pump inlet. Some coolant flows from the water pump, to the heater core, then back to the water pump. This provides the passenger compartment with heat and defrost capability as the coolant warms up.
Coolant also flows from the water pump outlet and into the engine block. In the engine block, the coolant circulates through the water jackets surrounding the cylinders where it absorbs heat.
The coolant then flows through the cylinder head gasket openings and into the cylinder heads. In the cylinder heads, the coolant flows through the water jackets surrounding the combustion chambers and valve seats, where it absorbs additional heat.
From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed."
Last edited by patooyee; 12-16-2015 at 04:28 PM.
12-16-2015, 04:32 PM
#90
Junior Member
Thread Starter
Alldata clearly shows the lower radiator hose (which would have to be the radiator outlet) as attaching to the t-stat housing. Since the t-stat housing then goes to the coolant pipe and into the back of the water pump that would mean that the back of the pump has to be the pump inlet. It also calls tat hose the "radiator outlet" hose. But the above description seems to contradict that flow path:
"From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed."
"From the cylinder heads, the coolant flows to the thermostat. The flow of coolant will either be stopped at the thermostat until the engine reaches normal operating temperature, or it will flow through the thermostat and into the radiator where it is cooled. At this point, the coolant flow cycle is completed."
12-16-2015, 05:34 PM
#95
Junior Member
Thread Starter
I'm an AN junkie. I've actually considered starting a performance plumbing company. I may still ...
Unless I hear otherwise I'm going with my original interpretation. It doesn't make sense for the coolant to flow down through the engine. All the air would get entrapped that way. On all the LS engines it flows up to the head where there are actually steam ports to help air find its way out. All the plumbing works the way I described. Even the Alldata description describes it like I do except for that one last sentence.
Unless I hear otherwise I'm going with my original interpretation. It doesn't make sense for the coolant to flow down through the engine. All the air would get entrapped that way. On all the LS engines it flows up to the head where there are actually steam ports to help air find its way out. All the plumbing works the way I described. Even the Alldata description describes it like I do except for that one last sentence.
Last edited by patooyee; 12-16-2015 at 06:06 PM.
12-16-2015, 11:34 PM
#97
the coolant flows in the t-stat housing, through the coolant pipe into the back of the water pump, into the block and up into the head and hour the head. the port in the back of the block provides coolant for the heater core, the coolant comes out of that port, through the t-stat and back into the thermostat housing just after the thermostat, and ends up heading back towards the water pump. this functions as a bypass circuit as well while the thermostat is closed.
12-17-2015, 12:34 AM
#98
Junior Member
Thread Starter
the coolant flows in the t-stat housing, through the coolant pipe into the back of the water pump, into the block and up into the head and hour the head. the port in the back of the block provides coolant for the heater core, the coolant comes out of that port, through the t-stat and back into the thermostat housing just after the thermostat, and ends up heading back towards the water pump. this functions as a bypass circuit as well while the thermostat is closed.
12-17-2015, 01:50 PM
#99
Junior Member
Thread Starter
On the intake between the middle two ports there is a small port that looks to be an oil port? I've removed my intake and blown air through it, it seems to be connected to the intake runners themselves. What is this, what does it do, and do I need to incorporate it into my custom intake manifold?
12-17-2015, 02:22 PM
#100
Junior Member
Thread Starter
Another thing, I picked up a 2003 L61 2.2 to use as a mock-up engine and to weld my new intake on to prevent warping. (It was totally fucked internally! It appears the timing chain guide broke allowing it to jump some teeth. Each and every rocker arm was completely broken off. Two of them were laying in the bottom of timing chain cover, one is missing. It's probably in the oil pan.) Anyway, the fuel rail that came on my engine is a stainless one with the typical GM-style smooth tube fitting. The one on the 2.2L is a cast aluminum piece with a metric fitting on one end, appears to have much higher internal volume than the SS one on my 2.4. Is there any reason I shouldn't use the 2.2 rail on the 2.4?