4G63T Coolant Flow?

[WFOVR4]

Im sure this has been asked before but I could not find it. What exactly is the coolant flow through a 4G63 turbo motor. If I got it right it looks like the coolant that comes into the turbo is the coolant that just came out of the motor and head. Why would this be?Wouldn't you want coolant that just went through the rad that is cool instead of the hot stuff that just came out of the motor?? Wouldn't this lower operating temps? Thanks for any info.

 

[Stapl3]

It is more important that the motor sees cooler coolant than the turbo. Your turbo would work fine without the coolant believe it or not, it has been done a few times. Your motor on the other hand requires the coolant.

 

[Defiant]

In a running motor, the engine and oil both run about the same temperature, and get there rather quickly. If flows from the radiator to the waterpump, through the cylinder block and head, and back out.

 

[AMS Eric #2]

The water pump pushes water into the block into the head. The water stays in the cylinder head until the water on the backsde of the thermostat reaches 195 degrees. The thermostat then opens, letting the heated water to flow to the top of the radiator thru the radiator out of hte lower rad hose, into the front water pipe and back to the pump. Thats why the U shaped water line for the turbo that scews into the water pipe is labeled turbo coolent feed line, and the one that goes to the tstat housing is the return line.

 

[poorboyj]

Thats why the U shaped water line for the turbo that scews into the water pipe is labeled turbo coolent feed line, and the one that goes to the tstat housing is the return line.

That is backwards. The fitting on the water pipe is the turbo return, feed is on the T-stat housing.

Jay

 

[AMS Eric #2]

Your absolutly right, the pressure is going to be higher under the thermostat. It was early in the morning, my bad.

 

[patsevo8]

This is exactly why Mitsu cars run higher than normal operating temps. The design of the cooling system is not so cool.

 

[pneumo]

The way Mitsu designed it the hot coolant coming from the T-stat housing goes into the turbo where it gets hotter, then it goes to the water pipe and back into the engine, bypassing the radiator.

It's odd that the coolant used for the oil cooler follows the same path; T-stat housing> oil cooler> water pipe> engine. It's no wonder we see several threads each summer asking about overheating problems with FMIC's.

 

[Defiant]

This is exactly why Mitsu cars run higher than normal operating temps. The design of the cooling system is not so cool.

A healthy DSM will maintain its designed operating temperature just fine. They're meant to run hotter than some, the ECU wants it and the systems are built for it.

 

[patsevo8]

Ya, it runs normal operating temps for Mitsu, but most imports(which every single one of my buddies have Honda, Suby, Acura etc..) run from 185-215 degrees. EVERY Mitsu I have owned have been PERFECTLY maintained and ran 235-245.

 

[WFOVR4]

Here is an idea, my radiator has an inlet and outlet for an auto tranny, could I route the coolant comming out of the turbo into the radiator then back into the coolant tube going into the motor??

 

[Defiant]

Here is an idea, my radiator has an inlet and outlet for an auto tranny, could I route the coolant comming out of the turbo into the radiator then back into the coolant tube going into the motor??

No point. Once you're up to temperature, the differences between the block and the radiator will be trivial.

 

[petegsx]

Bringing this back...
Which hose feeds the heater core, top of bottom? I want to put a shut off valve in the feed line so I can shut it off for the summer and open it when needed, looping is not the way I want to go.

 

[19Eclipse90]

The hose going to the extension off the water pipe will be the return. For a 2G and referencing the below diagram, that is the #11 hose:

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By default, then, the #4 hose would be the feed. Do note that it doesn't matter which position on the heater core these hoses go to; the heater core isn't going to work differently one way or the other (at least not noticeably).

The one hooking up to the water pipe will always be the return, the one from the thermostat housing is always the feed.

 

[petegsx]

Ok, thanks. Anyone happen to know the inside diameter of the heater core hose right off hand?

 

[19Eclipse90]

heater hose.

 

[petegsx]

Thanks

 

[Murdertalon]

I have a new option for improving the cooling system flow through the radiator if people are interested. I might make a new post about it. Its the one thing I think will actually make a difference and its not a crazy idea. Use a thermostat with a larger opening diameter. I just did it and its working awesome. -This is assuming everything else is optimal, and your radiator cap is holding pressure properly. The small thermostat inner diameter flow area is the one area I actually noticed could use an improvement. It made a good dent in my temps for the better. I talked to some oldschool mustang guys about it and they said people started making larger thermostat housings for their mustangs that allows use of larger thermostat and it was solving some over heating issues, bouncing the idea off of them they said it checks out. I have noticed a rather pleasing outcome personally.

I liked the idea initially of using a cooler thermostat until I researched more into it and found that if your engine is too cold its not operating efficiently and other problems can arise, so I decided against that. Looking at the thermostat design there is a lot of lip area, then it occurred to me that the other issue with narrowing a pipe area is it reduces flow and causes turbulence also compounding the issue of slowing flow. Increase the flow and increase the ability of the entire system to transfer heat faster.

 

[Vegas Smith]

Well make a thread about it already geez

 

[GST with PSI]

Use a thermostat with a larger opening diameter. I just did it and its working awesome.

What thermostat did you use that had a larger opening?

With the thermostat for our cars already being so small, I can't imagine a larger opening of any size would yield a noticeable improvement in cooling system efficiency. Not to mention, increasing flow would mean hot coolant spends less time passing through the radiator core. Again, I can't imagine that would improve your cooling system's efficiency. This may work for other platforms, but I'm not convinced it's a great idea for a DSM.

What results are you seeing on your car?

 

[Murdertalon]

Mitsubishi Part No. MD363571
80c For Lancer EVO 9
I will post actual temps bit later to give more of an idea where its maintaining under different driving conditions. I was even able to keep the widget on there. (thought it might need to be cut off but nope)

Cut 2mm off of it to fit into the dsm.

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[GST with PSI]

Interesting...

This reminds me of some crazy shit Jerry would do @94awdcoupe

 

[lasthope05]

I actually just drilled holes in my thermostat. Not too many though. I forgot the exact size and amount I drilled but it was equal to the area of the heater core feed. This was to remedy the additional pressure increase from deleting the heater core and plugging the lines. This way the coolant that would normally flow through the heater core and return to the water pump would instead flow through the radiator. Thus, overall, slightly increasing overall cooling efficiency.

Probably not too relevant but I wanted to put that out there since it was about increasing flow yet still retaining a functional thermostat.

 

[Murdertalon]

203-206.6 hard driving today in city, in 100 degree weather, while driving it dropped to a low of 83 ambient. I think that puts me spot on where they need to be. I saw it jump to 210 for a second and right back down to 203. I will update again when I get some highway driving.

Took it out again at night ambient temp 67, Coolant temp 195.8 city driving.