Coolant Re-route idea
 

Hi All,

Tell me what you think of this re-route
From what I can see it would work

Pressure differential = flow

This is how everyone does it.

where am I missing the pressure differential?

Thanks for the comments, more thoughts

Have you looked at this?

Wait, now I see it.

I got lost on your "t" going into the throttle body to turbo, but the other side of the turbo goes to the mixing manifold, which will be low pressure, making that whole system work.

Sorry for doubting.


I didn't know many people did this, seems a little complex. Mine is MUCH simpler. Like I added one big hose and swapped water necks simple. Everything still works right.


EDIT:

On a third perusing, it looks like the flow thru throttle body will be backwards from drawing, but won't matter at all.

What will matter is the low flow rate through the heater core.

He's merging the heater core outlet into the feed to the upper radiator hose. This effectively bypasses the thermostat altogether.

And yeah, the arrow between the front outlet and the throttle body is backwards. Water will be coming out of the front, going into the TB and the oil cooler, and then heading up into the upper radiator hose.

This link is better:

Coolant Reroute

Heater core no work when thermostat open, Kemosabe.

Actually, it would, if the thermostat ever did open. But I doubt it ever will.

He's taking coolant from the back of the head, before the thermostat, to feed the heater core. That's pretty standard.

But he's returning the coolant from the heater core to the radiator instead of the mixing manifold. This means that even when the thermostat is closed, 100% of the coolant being pumped (except for the tiny amount passing through the turbo) is going straight into the radiator after it leaves the engine. It's equivalent to not having a thermostat at all.

The one way around this would be to restrict the flow of coolant entering the heater core to the point where it's inconsequential. Of course, how you have reduced the overall flow of coolant through the engine when the thermostat is closed, and you'll warm up unevenly.

ok... just realized... you're right, the thermostat will be by-passed completely....uh oh...

I have looked at those re-routes and I wanted to get rid of the heater core line running from the mixing manifold to the heatercore, so I figured running it from the upper rad hose would be the same as running it from the lower one....I guess not (unless someone can chime in, because I really want this to work)

By really wanting it to work, I mean... its all done and I only have to make a mixing manifold for the upper rad hose and thats it.

I currently have no spacer where the thermostat is and I have an FM manifold WITH AN EGR tube as well and it all fits!! Thats what I like

Not even close.

Running the heater core return to the lower radiator hose is equivalent to running it into the mixing manifold, which is the stock configuration on both the Miata and all of the FWD vehicles that the B engine went into as well.



Sounds like a good design, other than the heater core return. I like that you're taking coolant for both the oil cooler and the turbo from the front of the engine- that's where the coolest water in the system is.

Is it plausible to block off the heater core completely ? IE I leave that entire section out completely ?

yes, but you will still need a path for coolant to travel from the back of the head directly back into the mixing manifold. The water pump needs a way to cycle coolant while the thermostat is closed, the heater core achieves this by always allowing an open path between the high and low sides of the water pump without requiring fluid to travel through the radiator. It works very similar to the way a bypass valve functions.

Heater core or not, you need to have some kind of path for coolant to circulate through the engine when the thermostat is closed. Otherwise, you'll get uneven warmup, delayed thermostat operation, probably some localized boiling, all kinds of nasty shit.

Older Toyotas (the '87 Celica GT is one example) had a cable-operated valve which governed water flow through the heater core. You could use something like this, with the return going into the mixing manifold. Have it open at startup, and then close it once the thermostat is open. And of course, remember to open it again when you shut down.

Volkswagen used a system like this to regulate the airflow through the fan on the Beetle's cooling system, where you moved a lever depending on whether it was summer or winter.

In the 1940s.

(Too many people were killing their engines because they forgot to throw the lever back after the snow melted.)

ok, here is another picture!

I'll have to buy another mixing manifold (cause the hole where where it used to go to heater core was welded shut) or I'll re-tap it and throw a SS hose on there so the heat from the turbo doesn't kill it.

on the picture, the line from the stock oil cooler and TB goes into the main return line (upper rad hose) It there a better spot? Should I T off of the heater core line somewhere instead where there is a constant steady flow?

I'll get there soon!



on a different note...I was approached by a few people asking if my car was going to be in Speedsport (largest car show in eastern canada) this year...that made my day :)

I just did a reroute today due to my turbo install. Easiest is to run a hose from the heater return to a splice in the lower rad hose.

I did it this way since I was leaving the upper neck in place and using a begi mixing mani neck.

Slightly off topic but does no one with a 94-95 block get their turbo water from beside the oil source (on the rear of the block) and put it back by the motor mount like the gtx/gtr bp's do? I understand people use the oil passages provided for factory turbo setups but does anyone use the factory turbo coolant sources? Too much work?

I've seen that passage on my block and thought about it....thats as far as it went

Wouldn't you have to get it from somewhere after the water pump and put it back before the water pump (or vise versa) to get enough flow.... ?

I hate to split the lower rad hose...but it might be done

I owned a gtx powered 323 prior to the miata and that is how it's done on them. Water nipple near the trans mount (motor mount on miata) and beside the oil output. I'm not 100% on the internal coolant pathways but I assume the motor mount one in where the water goes in and the upper, closer to the rear nipple.

I bought a hose (for a GM I think) at NAPA and cut that up, I spent $22 taxes in for 3.5' of heater hose and the rad hose.

Nice, well thats sounds good either way then.



So I ended up swapping the distribution block on the lower rad hose for one that is not plugged. and then used the stock steel pipe that was cut a little on the end to avoid the downpipe (also bent at a 45 degree)

As a note, it is hard as hell to get that block off with the AC and PS still on the car!



Hooked up and gave the base tune to the AEM EMS as well, the car kicked over but didn't fire (I have fuel and spark) I still need to pick up my AEM AIT and MSD MAP sensor thought, so that would do it.... should be running by next week.



If ANYONE knows where to tune in the EAST/NORTH cost...that'd great...never tuned before, so I'm scared as hell to blow this one up