Laur3ns

Hahaha I had a good laugh on the street that removed the scoop and the first post. Have a good day all

JasonC SBB

This won't help with the backpressure the pump sees if both thermostats are closed.

The outlet of the oil thermostat should go to the water pump inlet ("mixing manifold"). If it dumps into the radiator inlet, that will give you slow warmups.[/QUOTE]

hustler

iTrader: (6)

we have no doubt that your 2nd post will be flaming.

Why don't you just use a computer?

I'm excited to see something cool though.

Toddcod

iTrader: (8)

That was funny. " I rarely post here" first post. LOL

Oh well, laughter is good.

johndoe

iTrader: (5)

He's trolling M.net as well:

Hyper with ADD

The topics on the the coolant reroute topic have been extremely discussed first by Jason Cuadra many years ago and by many many others that claim they know the answer but as of this day have not resolved anything with the miata cooling issues. First off, let me say it has to do with marketing as the most likely verdors know the main reason your car is overheating. It also have to do bias information of "some call" engineerers or racers including Shaikh that don't sh$&% about this topic but that will happily persuade you to buy a coolant reroute set up. So by the time you buy a very expensive radiator, radiator cover plate, high performance fans and oil cooler, a begi scoop and a coolant reroute set up your bills are easily over $800.00. So... Multiply those amounts by a huge miata community and we have a very rich happy vendor(s).

Before I get into any arguments You ALL need to read solomiata.com

The link is here. Solomiata : Engine : Cooling system reroute

"The best fix is to reroute the water from the back of the head to the radiator input and eliminate that "mixing" manifold. "

just fyi , that article speaks by itself but needs some revisions. I accidentally happened to read it the other day and I have some comments about it. A long time a very wise man called Shiv Patak of Vishnu Performance Systems proved to the miata community that a simple add on of a dual-fed fuel rail will pretty much make cylinder no. 4 very happy. Just FYI, most pistons failure in miata engine I have seen to date happen with cylinder # 3. The issue has more to do with intake manifold design than anything. if you look at the Mercury Capri turbo, and JDM Turbo Protege Turbo GTR 1.8 engine, those manifolds were designed so that the Throtle Body sits right in the center of the intake manifold so that the airflow is even to all the cylinders. This topic was also discussed and argued in M.net by a good personal friend of mine, Richard a/k/a www.biggulp.net Go to his website and see the intake manifold and opinions he had in mind.

My point is rerouting the coolant to exit from the back of the head has nothing to do with the coolant overheating. The main issue begins when you add oil lines and coolant linesfrom the "mixing" manifold to cool the turbo, THAT's IT. So don't waste your time rerouting coolant from the back of the head, etc, etc blah blah. I am posting pictures of my set up in another topic. You are welcome to discuss / debate with me.

leatherface24

iTrader: (10)

Oh boy. Eli is here. I think your going to get eaten alive lol

I did basically what Hustler did with my set up and it works perfect imo. Granted I bypassed the heater alltogether because im in s. florida and i never use it.

heres my thread:
https://www.miataturbo.net/forum/t28981/

Oh yeah, the gold heat film thing has been beat to death so no point in mentioning it anymore Moving on...

After having it in for a few days now, I can say that my car gets to about 165 degrees in about 5 mins. and stays there pretty much no matter how hard I beat on the car. If im still in traffic, the temp will raise at its hotest at 180 degrees which isnt a bad thing at all. I think I have a little leak though on my inlet tube on the bottom of the engine so that could be why the temp raises a bit.

Joe Perez

iTrader: (8)

Ok, I'll bite.
First off, I'm slightly confused. On the one hand, you are pointing to Scott Ingram's article as supporting documentation, and on the other you're saying "don't bother taking coolant off the back of the head, just eliminate the mixing manifold."

Scott's approach to the reroute incorporated both methods, and for good reason. While you're absolutely correct that sending the coolant from the heater directly to the radiator is a best-case scenario in terms of cooling, it completely defeats the function of the thermostat in the engine. Were you to do only this, and not relocate the thermostat to the rear as well, then 100% of the coolant would flow through the radiator 100% of the time, and the thermostat would never open. Your engine would never come up to proper temperature either.

On the other hand, I agree that merely relocating the thermostat to the back, while leaving the heater return untouched, is also non-optimal. It certainly does improve the situation, as the front termostat is no longer depriving the engine of coolant flow, however a large portion of coolant coming out the back of the head will obviously still bypass the radiator and return directly to the engine.

For this reason, I agree that many of the current-gen commercial reroute kits are not entirely optimal, as they fail to address the mixing manifold. However I also argue that your apparent solution (as well as Bell's kit, with the heater going to the upper radiator hose) is also non-optimal as they will over-cool the engine.

The most optimal approach is one which addresses two main points:
1- By moving the thermostat to the back of the head, the volume of coolant flowing through the engine is increased.
and
2- One must likewise find a way to prevent a majority of the coolant from passing through the heater core and returning directly to the pump inlet, bypassing the radiator.

The first point is already addressed rather well by several commercial and homebrew offerings. It's the second point that is at issue here- the heater return.

The situation can be hand-waved by simply taking the heater feed from a post-thermostat location, and always returning it to the opper radiator hose. This alleviates both the over-cooling issue as well as the problem of un-cooled coolant returning to the engine. Unfortunately, it causes the heater not to work until the thermostat opens, and of course one must still provide some kind of bypass (such as holes drilled in the thermostat) to permit some coolant to circulate when the engine is cold.

Jason & Shaik's solution of using an inline oil thermostat to block the flow of coolant through the heater core when above a certain temp is a good one, assuming that a thermostat and water outlet are already in place at the back of the head to send coolant to the radiator. Frankly, I'd place the thermostat before the core rather than after it, but this is purely to prevent it from exploding, it would have no bearing on the cooling performance of the system.

A completely optimal solution would be a device which selectively gates the flow of coolant out of the heater core to either the mixing manifold (when cold) or to the upper radiator hose (when hot) as this would ensure fast warmup and maximum heater efficiency. Unfortunately, I'm aware of no such device, at least not at a reasonable cost.

My proposal is thus something of a compromise. Having relocated the thermostat to the back of the head, leave the heater return alone, but place a restrictive orifice in series with the feed to it. Some water will still enter the mixing manifold even when the thermostat is open, however the restriction will force a majority of the coolant to select the lower-resistance path through the thermostat and into the radiator.

Joe Perez

iTrader: (8)

No, the point is that you eliminate the oil thermostat in this scenario. The restriction is a means to improve the efficiency of the system above what you'd get with a stock engine-heater-mixing manifold configuration and approach the functionality of the oil thermostat, but without the cost and extra plumbing involved with the oil thermostat. When the main thermostat is closed, coolant will flow through the restriction, through the heater, and into the mixing manifold. When the thermostat opens, a small amount of coolant will still flow into the mixing manifold, however the majority will seek the lower-resistance path through the thermostat and into the radiator.

Having thought about it last night, putting an oil thermostat inline between the heater and the mixing manifold scares me. This will tend to increase the local pressure within the heater core well above average system pressure when the engine is warm and the oil thermostat is closed. A restrictor placed on the inlet to the heater, however, should actually reduce the pressure within the heater core to less than system pressure.

Raise your hand if you enjoy replacing blown heater cores.

Joe Perez

iTrader: (8)

I've pruned the thread just a bit to remove all the bickering about who posted whose pictures first. Those who want to see Hyper's system can head over to this thread and comment about it there. I'd like to keep this thread centered on the Bell system, and the related discussions which it spawned.

levnubhin

iTrader: (30)

Good, now I have a question. When I remove the front housing and put a freeze plug in there, where should I plum the feed line for the turbo? I looked at Hustler's pic and I can see the line that goes to the mixing manifold but where is the other?
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Joe Perez

iTrader: (8)

One potential location is at the back, before the thermostat. Essentially in parallel with the heater core.

If you block off the front thermostat housing with an aluminum plate rather than a freeze plug, you could thread a fitting into that plate and get a somewhat cooler supply of water. This is how M-Tuned's forthcoming system works.

I've also heard of one guy who took it from the port over on the intake side of the block which normally feeds out to the throttle body and the oil cooler. This seems a bit overly complicated.

levnubhin

iTrader: (30)

Awesome! Thanks Joe.
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Joe Perez

iTrader: (8)

Oh, and I almost forgot. On the 1.6 and some of the early 1.8s , there is a threaded hole on the exhaust side of the block, back by the flywheel, right next to the one we take the oil from. It's an M12 x 1.25, and I'm pretty sure it's where the 323GTX took its water feed for the turbo from.

I don't recall the exact cutoff date when they stopped providing this fitting, though I expect it was probably around the same time that the oil feed went away.

levnubhin

iTrader: (30)

Intresting, I'll have to look for that.
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JasonC SBB

If you put enough of a (simple) restriction to be significant in terms of cooling capacity, you will also be reducing the heater capacity.

In the stock config, the heater inlet is at the back of the head which has a certain X psi. The heater outlet is at the inlet of the water pump, which is at a lower pressure, Y psi. This delta pressure is what forces coolant through the flow resistance of the heater core.

If you shut off the exit of the heater core with a valve or t-stat, it just means the whole heater will sit at X psi, which is the pressure that the heater inlet is with a stock configuration. No big deal.

BTW what you guys call a "mixing" manifold, is simply the 2nd (an dmid size) of 3 water pump inlets. The big inlet is where the lower rad hose connects. The smallest is the little nipple.

james399

iTrader: (12)

Hustler, I'm looking at your design, and please correct me if I'm wrong. with the custom piece you had made, the larger outlet post t-stat that connects to the upper radiator hose, so it will only flow once the engine hits normal operating temp. and the thermostat opens...

The smaller outlet from (blue outlet) the piece you had made runs coolant to the heater inlet, and the heater outlet runs to the upper radiator hose...

so you are able to maintain flow even with the the thermostat closed.....

so a few quick questions, on the water pump inlet that connects to the lower radiator hose, did you just block of the smaller inlet that originally mixed hot and cold?

also on the small outlet on the original t-stat housing what did you do to the hoses that ran to the intake manifold and the oilfiler housing and to the back to the rear of the engine?

and last but not least i have a 95 1.8 and it has two sensors on the back of the head where the water leaves the engine? what are those for, and can they be left unplugged?

I don't know if this matters, but i'm prepping this 1.8 to drop into a 1.6... as of now i'm just going for the swap to get it running, and then boost...

-james

Joe Perez

iTrader: (8)

The two sets of pictures he's posted appear slightly contradictory:

vs.


My guess is that he either blocked the smaller inlet, or replaced the stock mixing manifold with another piece. Same deal either way.

The problem in this design is that with the heater core outlet going to the upper radiator hose, there will always be a significant amount of coolant flowing through the radiator, even when the thermostat is closed. Hustler is baller enough that he can just swear at his engine a couple of times and it'll come up to temperature, but for most of us, this would cause agonizingly long warm-up cycles.


Well, they didn't actually return at the thermostat housing, they just passed by it on the way to the mixing manifold. In the first picture above (which I think is the Bell piece) he's clearly installed a brass tee fitting as a return. The water coming from the turbo and from the oil cooler can both return anywhere on this inlet pipe.

The sensor with two terminals is the CLT sensor for the ECU. The one with a single wire is the CLT sensor for the dash gauge.

brgracer

iTrader: (14)

Okay Joe,

Reading thru this thread, I like your idea best, and I was having a similar problem as the OP as my reroute has the front of the head plugged, thermostat in back of the head with return to upper rad hose, heater core feed pre-thermostat, and heater core return into the upper rad hose which works pretty much like having no thermostat, hence the cooler operating temps.

So here is my proposed execution of your idea of basically a temp diverting switch for the heater return. Please excuse the poorly drawn diagrams.

First, my assumptions. Permacool style oil cooler like one in this link: Remote Oil Thermostats. I also assume that the oil cooler works as pictured below when oil is less than 180 deg (1st picture) and then hotter than 180 deg (2nd picture).



My proposed plumbing for the heater return. 1st picture is when water is less than 180 degrees. 2nd picture is when water is hotter than 180 degrees. The thing I really wonder about is the 10% pass thru figure when cold and how that might change when using water, which is much less viscous than oil.

james399

iTrader: (12)

Thnx Joe you guys are the bestest!



there is so much i want to do to this little car.... so much to learn... lol....