coolant flow question
 

Im doing a 1.8 swap and while cleaning up the motor today i noticed the small fitting that comes out of the thermostat houing has a hole in it.
there are small hoses goes from the tb to the thermostat neck and from there to the side of the engine by the water pump.
all other fittings seem to be in good condtion except the t that comes off the t-stat housing. Can i just pull out this t and plug the hole in the housing and run one house from the tb directly to the wp fitting? witch way does the water flow? will this effect anything? also note i will be installing a ms to run the motor if that changes anything with the iac and need for the lines at all?
sorry if my spelling isnt good and my puncuation is lacking also.
any help apriciated

That's not a good idea. The purpose of that fitting (in addition to providing a return from the TB) is to provide a leak path to circulate water past the thermostat so that it opens in a timely manner. Without that leak path, your thermostat will open very late -- your water temp gauge will nearly peg before it opens. This is a byproduct of using an engine meant for transverse mounting in a fore-aft configuration.

The better solution is to do a coolant reroute and remove all of that stuff completely. I just did one and it works great. All the little hoses are gone.

ok where can i find more info on this ccolant mod. what did you use? im sure there must be a cheaper way than the big money kits. im not a fan of kits anyway.

Easy Coolant Reroute – part 1 — revlimiter.net
Sorta-easy Coolant Reroute – part 2 — revlimiter.net
The Coolant Reroute Strikes Back — revlimiter.net

This is about the cheapest way to pull this off and have it be effective. The M-tuned/SuperMiata is a nice option and has better firewall clearance, but most people feel the thermostat opens too late.

You can also go nuts and start drilling into your head for an even more custom solution, but that will happen if you search!

ok that looks great and all but this still uses the small hose from the tb housing. so this really didnt answer my?

i do have a neck from a 1.6 are they the same?

I just posted a bunch of pics on my reroute in my build thread.

Since I'm on a budget and I have a 1.6 parts engine in the garage...I was running doing it this way
1. Install thermostat in the back of the head....put the temp sensor on the head where there is a plug now, use the 1.6 thermostat housing on the back, and run a house down the hot side for a reroute..and freezeplug the front....or just swap the neck from the 1.6 to the 1.8 and fix the broken part and maintain factory coolant flow....I can't justify over $150 in parts for a cold side reroute....any input?

The main reason for a reroute is better and more even cooling, especially for cylinder #4. That's why I did it.

If all you're trying to do is minimize expense, why don't you just pick up another 1.8 waterneck with a good "T" for cheap? There might also be a brass fitting at the local hardware store that can substitute for the "T." It's easy to pull the "T" out, drill and tap for 1/8" pipe threads.

Your 1.6 waterneck might work. Takes a different upper radiator hose. There might also be clearance issues with the intake. Those should be obvious.

https://www.miataturbo.net/attachmen...ine=1360602321
https://www.miataturbo.net/attachmen...ine=1360602321
https://www.miataturbo.net/attachmen...ine=1360602321

The second image is blocked through work, so I don't know if it still links. None of those diagrams show the hose that goes to the factory oil cooler along the cold side, which then goes into the TB. You can cap off the coolant lines on the valve on the TB, but the electronic parts need to stay hooked up if you want A/C and P/S idle bump. I've been debating deleting mine and setting idle at 950 all the time, the harmonics of my interior panels are better up there.

More info here: https://www.miataturbo.net/race-prep...y-style-49344/

In short, I believe you can cap off the water neck line and run the hose to the WP temporarily, as that looks like that's where it goes post-reroute. Do not do this. Keep reading, but you can not bypass the line through the water neck without relocating the thermostat because the factory design uses this hose to run hot coolant past the thermostat for proper function.

those lines have nothing to do with a/c and/or p/s idle bump.

nice try though.

you could have read the page of the FSM in which you sourced the first imagine and it would tell you exactly what the lines in the TB to the air valve are for, instead of posting non-researched, incorrect, drivel.



God i really fucking hate reroute threads.

Braineack, that was my intent, but my wording left it murky. Fixed it.

rawr

Am I always supposed to feel like I'm being trolled on this forum? :giggle: XD

This wasn't even a reroute thread. OP asked whether he could delete the bleed line from his front thermostat housing because his T fitting was leaking. We correctly told him that if he did that he would have issues with delayed opening of the thermostat.

Now, you enter and state "[i]n short, I believe you can cap off the water neck line and run the hose to the WP temporarily, as that looks like that's where it goes post-reroute." This is incorrect and will lead to late thermostat opening issues.

So, you see, you're not being trolled. We're just trying to protect OP from bad info.

Then where does it go if you brass plug the neck? All the diagrams I see show it as going through the oil cooler, then TB, then water neck, then the turbo and then back to the mixing manifold/water pump inlet. With no water neck and no turbo I can assume that you then plumb it from the throttle body to the mixing manifold.

https://www.miataturbo.net/attachmen...ine=1360608303

Is this incorrect? Should it return to the upper radiator hose instead?

correct. it ultimately goes there anyways...

You're really not getting it Scary. OP is NOT doing a reroute. If you don't move the thermostat to the back of the engine, you MUST keep the bleed line at the water neck for proper thermostat operation. If you move the thermostat to the back of the engine with a reroute, then the water neck bleed line (and the water neck itself for that matter) no longer has a function.

you're assuming I even read the thread...i scrolled straight to pictures and happened to catch a few lines of text unrelated to anything.

Big picture guy!! I like it.

if someone did the stats, I have a higher post count in threads with pictures than without...


probably 10:1-20:1


i also derail threads to talk about myself and my shortcomings.

Ah. Understood. Edited old post with new information.

To the OP, if you want to spend less on parts and still do a reroute there are people on here doing spacerless reroutes. The cheapest way to get out of this is to try and adapt your 1.6 neck, but it might be easier to just buy a 1.8 neck from someone who has deleted theirs. IIRC I saw some on one of the used parts sites in the $20-$30 range.

46k posts
just sayin:giggle:

ok so upon further research i have decided to do the re route. there will be no better or eisier time than now when the motor is on a stand...i found parts to do it cheap..there is this fitting..Ford F1CZ 8597 A | eBay
this is from the back of the head of a ford escort 1.8 gt. it shall replace the 1 line fitting that is there now that feeds the oil cooler. now the small nipple will feed the oil cooler and the larger one will be plumed to the heater core...then i can thrown a stat in the head and put my 1.6 housing over it...the 1.6 housing will hold the temp sensor and i can run the coolent line down the hotside to the radiator. the front has been tapped and plugged and the small lines now bypass the neck to the mixing manifold. front thermostat removed and capped off also...total money spent $55 with hoses..now the only issie i have left is i needed to remove the egr crossover tube to fit all this behind the head. the block off plates with shiping is crazy....maybe i can offset that by selling the tube? or should i just cut the tube and have it welded at each end? i dont think im missing anything.

Neat. I always wondered if you could just buy those separate nipples. You'll need a hose with a pre-formed 180* bend in it, or you'll kink it going from the nipple to the heater core. You could also use a spring inside to reinforce it.

Someone over on M.net is using the stainless flexible gas pipe from the hardware store for his EGR pipe. He claimed that the tube just screws onto the header fitting (probably only 94-97 and 01+ headers) and that he used a compression fitting on a cut piece of the intake side of the tube to join it together.

EGR Hard Line simple Fix - Coolant reroute - MX-5 Miata Forum
Proflex CSST

The EGR tubes on my Camaro and my S10 were essentially large bore heavy wall versions of the same. It should work fine, but YMMV.

I recommend that you test fit as much as you can on the engine stand. Much easier to take care of conflicts there. Even with my simple reroute, I ran into some conflicts that would have been a PITA to remedy after putting the engine back in.

when my motor was out i cleaned the back wall and bent that lip in with all the calking on in. Could have been a bad move by me but with that thing bent in and no coil pack, there is a decent amount of room back there. I was worried about being able to change my thermostat but i'm not anymore! It'll be even better when I upgrade my ms and can remove the cas from the back.

note: the lip im talking about isn't in the way of anything specifically but I could see catching tools and knuckles on it.

I was thinking I could find a hose at the auto stouter that was close enough but the spring idea is also a good suggestion....don't think ill bother with the egr there is no emissions here....and I got a super thermostat that is designed to stay open if it fails..so I won't get stranded anywhere and I won't need to rush to fix right away...peyote down here sometimes run with no thermostat at all but I thought this was a better choice...snag Tire it might be a pita to change if it fails.....

IIRC there was a reason not to get Stant's SuperStat thermostats for the Miata.

https://www.miataturbo.net/general-m...rmostat-66774/

I'd keep the EGR hooked up, but I also live in a pollution controlled city. It's one of the only emissions systems to actually work (the others being a cat, vapor canister, and the PCV valve) and does increase MPG's at cruise as well as reducing NOx. It also makes your intake filthy, but I've been told that the cause of that is cheap gas and poor maintenance/burning oil.

Sooner or later the gub'mnt is gonna push the EPA standards nationally, and by removing emissions equipment for convenience you're just another "evil street racer" driving a "gross polluting vehicle" that they love to make examples out of. :giggle:

Now if we were talking about deleting an air pump (80's-90's vehicles) and installing a proper catalytic converter that didn't require an oxidation step, then I'd be all in with you about removing that crap.