Thank you. I also didn't think BEGI's "coolant reroute" was what everyone else considers correct. It's a shame too, I know there is a market for a good coolant reroute kit because I get emails about mine weekly.

I'm sure BEGI's is better than the OEM and OEM is probably fine for 99% of people out there. I only did mine because I had the engine out and figured what the hell. But I figured the point of a proper coolant reroute is to pump all the coolant across the engine like the FWD cars.

 

The original coolant reroute came about to even the cooling of the engine NOT to reduce engine temps. IOW the average temp is the same, but in the OE configuration temps range from cylinder to cylinder with number 1 being the coolest since it receives the greatest flow and number 4 being the hottest because it receives the least flow. With the reroute, coolant flow is encouraged to flow more evenly through all paths to the rear of the head.

Kia addressed this when they used the originally fwd-only FE in their rwd Sportage by changing the coolant passage bores in their head gaskets. By reducing the bores on at the front and enlarging them at the rear cylinder(s), they forced more coolant to the rear even though the FE got a front rad exit- like the Miata's OE configuration. Not the ideal fix, but cheap and effective.

It looks to me as though the point behind the BEGi reroute is reduce overall engine temps by eliminating the return/recirc path of the heater core- albeit at the price of speedy interior heat. IMO I would find other means to reduce engine temps first- but that's because I want my heater to warm up quickly.

 

I did the coolant reroute when installing the 1.8 Escort GT engine in my 91. I used the thermo housing top from the 1.6 and ran the large hose around and up front. Instead of using one complete piece of hose I found that chrome finished sink traps made of brass from Lowes is the exact diam. and so I fit them in where needed. Works good and the chrome looks good. This car is not turboed nor raced but it warms up quick and the temp never moves no matter how hot the day or how hard the drive. The escort engine normally has the outlet for heater and rad at the back of the block (front wheel drive) so the only challange was running the hose. The heater hoses run the same as original. FWIW

 

As time goes on, keep tabs on the sink trap parts. Wouldn't want them to corrode from the inside and blow through as they get thinner.

 

So do I even need to run coolant to the heater box? Can I just eliminate that? I live in Florida, not a real need for the heater.

 

you can bypass the heater box, but you need to make sure you don't just plug the heater hoses or else your engine will not get coolant.

 

IMO, unless you're going to pull the core out, I wouldn't bother just not running the lines.

Personally, I'd keep the heater system functional. It's actually a good place to slough heat. Say you're on the highway or track and you see the temp needle climb up where you don't want it to be. If you turn the heater on, it will take some heat energy out of the coolant, and hopefully give you enough time to get off the road before something bad happens.

 

I may be wrong but isn't BEGI's reroute not intended to fix cooling problems but is to eliminate the interference between coolant lines and turbo parts?

 

ding ding ding!

 

go read their website before you spread bad information.
their "bypass" kit fixes the interference issue.
their "reroute" kit is a different item.

 

I've read the website. I'm new and did preface my statement with "I may be wrong". The Begi "bypass" fixes the interference but the reroute is also part of that. It would appear that they are simply taking the hot water returning from the heater and running it around the intake side of the engine and t-ing it into the inlet side of the radiator. They don't appear to be rerouting the flow in or to the block. Again, this wouldn't be intended to fix cooling issues. Maybe Steph can clear this up.

 

It improves coolant flow by cooling the fluid prior to it entering the engine.

The heater output re-route will not affect heater function due to the fact that it is still drawing fluid from the back of the cylinder head. We are just cooling the warmer fluid from the heater before it goes into the engine. Thus resulting in lower temps. In reality is this a huge change? No. However every little bit helps, even if it is 2-3%.

The diagram on page one is a good system with one exception. The heater output needs to go to the radiator inlet for cooling prior to entering the engine. Are you proposing moving the front thermostat?

Ben is correct, the by-pass removes the lower radiator hose to make room for turbo parts. The Re-route is to cool the engine - somewhat. Every little bit helps.

We do have a "race" re-route in the works that will run it differently than the one on the website. The "race" re-route is more of what the DIY'ers do. We'll have more info on that in a week or so. There is a big project in the works.
Stephanie

 

I saw the post for Corky looking for a junk 1.8 head figured this is what you guys we're looking at fabbing. Should sell well if it's a easy in car install, sure it will be top notch.

 

I did a modified version of BEGI's reroute with the path with the red arrows splitting off - one side going to the top of the rad and the other side going through the turbo and then to the top of the rad. It added about 1,000 hose clamps to my coolant system.

 

Actually that would be reducing coolant temp, not improving coolant flow.

I think it will- it's going to take far longer to get hot coolant to the heater if you're not immediately recirculating it thru the block. BEGI sends it back to the radiator to extract heat, heat needed for warming the cabin. The idea for quick heat is to NOT bypass the Tstat.

I'm not debating this. There is merit to the BEGI reroute for this purpose, BUT this goes back to my point that there seems to be two different goals for the reroute. As the BEGI goal stands, it's to make some kind of impact on the overall coolant temp. But the original reroute has it's origins in balancing the coolant temp throughout the engine. The thinking was that because the coolant entered the front and exited the front, the number 4 cylinder wasn't operating at a temp similar to the number 1 since it wasn't receiving nearly the same coolant flow.

The point of this reroute is keep the OE heater performance, while balancing overall engine coolant flow. That means recirculating the coolant so the engine warms up (and warms the coolant up) asap. Sending the coolant back to the engine, forces more cold coolant back in the engine at warmup. Essentially the heater core becomes a Tstat bypass in the BEGI routing during warm up. Moving the Tstat to the back with the primary rad return, guarantaees an OE style heater routing and OE Tstat position. So when the engine is up to operating temp the Tstat opens and send the "hot" coolant to the rad for cooling via a preferred coolant flow covering ALL cylinders front to rear. Yes, the heater still dumps the hot coolant back to the pump w/o cooling, but as stated it's nominal.

IMO if one was looking to control elevated coolant temps, the environment should first be identified. Then focus on optimizing the system for that environment by any of the following: filling all the gaps left between OE parts, parallel fan wiring, higher flowing fans, different coolant mix, larger rad, etc. - rob

 

Sorry Stephanie, but it does affect heater warm-up time. The coolant reroute that I did sends the coolant from the heater back to the rad like yours does. It now takes about 3 times as long for the heater to get hot after a cold start.

Once the car is warm, there is no difference in heater function.

 

So basicly to get this to work youll need a 2 way valve that switches just below thermostat opening temp...

On startup the coolent runs oem, when hot trough the radiator.

I don't think the disign of the miata is poorly as the coolent will be extracted at about the same flow on the front and rear of the engine.(hole in thermostat is not that big)

The only thing to worry about is the 'warm' heater return line.

 

My "reroute" was done by removin the heater and routing the line from back of the head to upper radiator line instead re-entering the engine. On that line I added mechanical water temp gauge.

hrk

 

Same as mine but with turbo cooling thrown in there too. What did you do where the coolant used to "enter the engine". I left the aluminum tube on there and just put a cap on the end but I hate that setup. I'm just looking for good ideas...

 

Rubber plug from autozone clamped around the tube. I also turned the whole piece 180 degrees, so it points forwards, to make room for turbo hoses.

hrk