The second one is functionally the same as OE when it comes to pulling for the heater core. It's still pre Tstat, just moved to the front so you don't have to use a special spacer to make for a source at the rear of the head. That said TomBRG drilled the back of his 1.6 head made a heater core source for the pre TSTAT too.

It's if it goes through the rad or not...

Im doing this

Attachment 197100

You mean, this?

fyp

Nice. Last time I checked that page was down

wut?

Reaction time of the thermostat is a bit slower than if it were mounted closer to the head. It will continue to divert hot water into the pump inlet for a while when your head heats up quickly.

Actually I think the idea is to prevent icing of the throttle body in cool climates. Cool, moist air travelling at high speeds (such as the intake of a Miata) can deposit ice in much the same way as happens to aircraft wings at high altitudes. Imagine driving along the freeway for 100 miles, throttle open at a steady clip, but then you come to your exit and take your foot off the gas but the engine keeps pulling because the throttle butterfly is iced up in the open position... fubar.

Has anyone messed with this reroute? The guy says it can't be done on a pre-2001 car because of the coil packs, but it should still be possible using the M-Tuned housing... right? You would have to use a plate for the front of the engine though I think because the M-Tuned housing has a heater core outlet too...

EDIT: Never mind, I'm a tool - you would still need the M-Tuned thermostat housing or a suitable substitute...

Forget the stock coil packs. A toyo COP set up runs you $100, and has performance gains to boot. I've saved more on spark plug cables since I did it than I laid out, and yes, there's a lot more room for everything now, including my reroute.

Resurrecting for an update - Rafa, how did it work long term? Looking for a cheap reroute and I liked the idea of this BMW piece at 180*F, and it looks like the key was a restrictor on the heater core line down to 3/8"?

Also, it seems like if the valve were flipped it might want to flow more to the rad and less to the heater/bypass - so angle port to the heater core, side port from head.

https://lh3.googleusercontent.com/ES...=w1239-h618-no

I would think moving it to the rear of the head on the passenger side means thermostat closer to the head for faster opening, and shorter heater core run.. Assuming I drew things properly, that is.

https://lh3.googleusercontent.com/TX...a=w751-h618-no

Thoughts, all?
Wallyman

8 years, 2 months, 25 days. Not bad...


Your photos don't work for us. Pro-tip: you can't hotlink directly to images in your Google account. Gogole's rules, not ours. The look fine to you because you're logged into your Google account. Those of us who are not logged into your Google account see nothing.

Download 'em to your local PC and upload 'em here.

What can I say, I like old things. Seemed smarter than a new thread asking about some very old thread and having to explain it all. Also, I'm curious if it worked long term, and why nobody else really tried doing any more with this piece. Seems like a wickedly simple and cheap fix which you guys generally love (if they work that is).
Well that used to work.. I can't get the upload function to work, which is why I tried to do it that way. The upload screen will take them, show then and when I hit the upload button the popup closes and they are not there. Tried 3 times, using chrome and IE.. I'm going to blame the company laptop cuz I got nothing else. If there is still need, I can try to upload from home when I get there Sunday.

Verbal version:

Rafa connected his with the angled end towards the mixing manifold, the center tap came from the back of head (sixshooter commented on it in #106), straight end port goes up to the radiator. Based on the sketch in #112 by Stankcheeze, it seems like the hot water from the head will have to hit the face of the thermostat, and go around that face to route towards the radiator, executing 4 x 90 degree turns essentially. Flow hits face o thermo, turns 90 towards side port (the only open option). Flow hits restriction, some turns 180 back the way it came. Assuming it is hitting the original flow, the path of lessor resistance is the straight port. So the flow goes into outlet towards radiator, hits back wall and turns 90 to flow to rad. Over-simlified but it's not a clean shot at all and I think that contributed to the flow wanting to go to the mixing manifold and not the rad.

I'm wondering why not connect it with the side port from the head, angled port to the heater core (restricted). Thermo closed, water will go in via side port, and then route through the small line to the heater core like stock config. When the thermo opens, the flow will hit the side of of the thermostat, like a knife cutting the flow. The restricted side will get some flow (limited by it's smaller opening), and the resulting build up in back pressure should force the majority of water to the straight port via a single 90 degree turn.

https://lh3.googleusercontent.com/nS...A=w751-h618-no

https://lh3.googleusercontent.com/-7...=w1239-h618-no

I tried another way to link, did the images show above here?

also pro tip: you can right click and "copy image" and paste it into the MT uploader and save yourself a few steps and random files on your disk.

Thanks Y8s. I tried uploading but it just wasn't taking, not sure what the issue is. It shows the preview, I can put text below the image but when I hit the "upload" it just closes the window and nothing happens. Did the images show at the end of my long winded second reply? I logged out of google and it still shows for me so I think they should work for everyone.

I'm hoping you guys can weigh in on this, it seems like a super simple remote thermostat setup, the 'hardest' part being a reducer on the heater core feed and extended the wiring (on my 1.6 car), the rest is dead simple and super cheap without a spacer.

The routing shown in "Rafa" in your first image makes no sense to me.

The routing shown in the second images makes sense, aside from the fact that the heater core won't get any flow when the thermostat is open.

does the thermostat fully seal off the angled port? I didn’t get that impression from the various discussions and descriptions.

I think so. This is how bypass thermostats are supposed to work:

https://cimg6.ibsrv.net/gimg/www.mia...5138a96881.png




EDIT: Everything below describes a design which is no better than a traditional rear-therm layout. See post 163 below for a better design.

If it were me, I'd leave the heater core stock on both supply and return, then install the new thermostat such that:

https://cdn4.pelicanparts.com/techar...mall/pic08.jpg

Red= in from head
Yel = out to mixing manifold
Grn = out to upper radiator

Well those sure make it look like it is intended to seal. Funny nobody mentioned that earlier? Reviewing the previous info that means Rafa was seeking complete bypass of his radiator when warm??

The only way to keep stock heater core routing is a spacer or some modified rear housing, since it’s a cover flip front to rear.

I’m still questioning the full seal off tho. The distance the thermostat would have to travel is probably greater than two inches... I may buy one and boil it up to see how it performs to satisfy my curiosity

In the name of science, I paid $15 for the 140-0263 part and will test it out next week when it arrives. 👍

Joe, I think you are right based on this image:

http://www.performanceforums.com/for...0&d=1460360612

Looks like it's a dual piston, and when the thermostat opens is seals off the angled port.

I'm now looking at a Land Rover PRT (Pressure Relief Thermostat) part.. info: https://wiki.seloc.org/a/Pressure_Re...ote_Thermostat

So, perhaps a different one like the PEM100990 ($12 on ebay). Works on the same principle (single straight is out to radiator, diagonal would be from head, top straight would be to heater core as it has some 'metering holes' but does appear to seal when the thermostat opens - see post #4 here for photos and explaination) Ordering one of those to play with too. I think that could work, and given it's straight on design you could add more or larger metering holes if the heater core isn't getting enough flow.