I don't know, buddy. I've got no experience with AEM O2's.

Sorry.

It's cool shooter. I was able to do it without hassles. Thanks.

Here are some pics:

Rafa,
Is that pipe (see pink arrow) connected to the bottom radiator hose? If so, I think there might be a problem. I believe that when the thermostat is open, you will have very little coolant flowing into the radiator and most of it going back into the engine hot. I'm double checking this. I have to find the picture of that inline thermostat again. More to follow.

Thanks for the pics. That looks great, there's no way mine is going to come out that nice.

This idea deserves a MacGyver award.

http://i158.photobucket.com/albums/t...statconfig.jpg

If the one with the pink arrow is going to the radiator bottom hose, then your radiator will be bypassed even with an open thermostat.

I remember that you said you are not running a heater core anymore. If that pipe (purple arrow) is going to the bottom heater hose here is what is happening:

New Diagram -- The green arrow represents coolant coming from the back of the engine. The red arrow shows where it is going when the engine is cool and the thermostat is not open. When the engine gets warm, you are wanting it to go where the blue arrow is pointing, but it won't. It will still find it easier (less resistance) to keep following the red arrow. Very little water goes through the radiator and your engine will overheat in this configuration.

One little solution. Restrict the flow going in the red direction down to a very small amount. You still need to have this flow to cause warmed coolant to pass by the thermostat, just not very much. You need an opening about the size of your stock heater core hose diameter or even slightly less.

You could take a washer or a restrictor of some sort and block the neck of the pipe. Anything to get that flow down to a small amount. Block the red arrow hose or the purple arrow pipe with something and drill a hole in the blockage, maybe.

A big socket that just barely fits in the hose will also work well and has a nice small opening in it already. Slip it in the hose and put a clamp around it so it won't move. That is a nice, easy to find restrictor.

Good luck. I hope I'm just looking at this incorrectly.

Good explanation sixshooter, makes sense to me.

I think you're spot on. I've been reading and rereading both your posts and it sure makes sense. I can tell that it took some time to see the water flowing through the radiator last night.

What would happen if I just blocked the outlet (marked by you with the red arrow) that goes to the T made connecting it to the lower radiator hose?

I know it took a long time last night before we could see the water flowing through the radiator. I just thought that once the cooling system started to flow regularly and the T-stat opened it would be no problem but I can see your point. Water will indeed search for the path of least resistance.

In this pic: see the outlet that says from "cylinder head"; that's the case.

We cut the elbow of the one that says to "heater core" and indeed connected it as you explained.

I have to see what my options are locally about restricting flow. Do you think that the size of the car's heatercore pipes is small enough or should I search for even more restriction?

Many thanks,

That's why I consider myself a Tampa guy! :bigtu:

You're not looking at it incorrectly, you just don't have all the information. There's a divider in the neck that splits the flow roughly 75/25 in favor of the radiator. It's a great design, really, I'll post pics of it later.

StankCheese; are you saying that I shouldn't restrict the flow? I was almost on my way to the shop.

Be careful with the restrictor. You don't want to choke off too much flow when the thermostat is closed.

http://i44.tinypic.com/2gwzv9w.jpg

The bracket on the right doesn't seal all the way around, so it's not really a divider as I said. Once the thermostat pops open, the "hat" on the thermostat, which does make a pretty good seal, will be roughly halfway down, with the spring area on the right side which will inhbit flow towards the heater core side. Red below represents the thermostat, blue the coolant flow.

http://i39.tinypic.com/nosmwz.jpg

Thanks for that explanation. I think I could make some sort of flap to seal some of the lower red part you showed.

BTW, I haven't done anything else yet. I decided to wait for your post.

Max temps I get when running around town with the A/C on are 210*. It won't go above that no matter what so it sure works much better than before.

THANK YOU ROB! :bowdown::bigtu:

BTW StankCheese; is the Viagra bottle in the background meant as some suggestion for me to use? :laugh:

I'm old but not that old! :giggle:

Stankcheese,
That is very helpful information.

Rafa,
I see the design characteristic that Stankcheese is pointing out, and that is helpful to your cause, but I would say it is still a larger opening than I would prefer if it were me. The most important reason is the coolant will find a much easier and more open (less resistance) path through that neck opening than through the radiator. I would want an opening about the size of the inside of the stock heater hose.

You still need that flow to occur, though. Don't think about blocking it entirely. It is necessary for warm coolant to flow past that point to cause that thermostat to sense it and to begin opening. No flow would mean no opening and that would be bad. Too much flow, which is what I think you have now, will cause the coolant to easily bypass the radiator and go right back to the engine (still hot).

It may work moderately well when the system is not being pushed too hard, but I think it is bypassing too much to perform at its maximum efficiency. This is just one fellow's opinion on the matter. Good luck.

Rafa, what did you use on the back of the head? I've been messing with mine on and off the last few days and I can't seem to get anything to work. Where did you get the water neck from? Is that where the water temp sensor is still located? Do you have a spacer in there or is the water neck bolted directly to the head? Is your EGR hooked up?

Sorry for the stupid questions, what looked like a very simple concept has turned into quite a headache.

Sorry for the thread jack!

https://www.miataturbo.net/forum/t33806/#post393865

We sell our rear housing on its own and it will certainly fit any NA or NB with EGR installation.

I finally got mine together, unfortunately I'm using the stock waterneck that went to the heatercore so it's much smaller than it should be but it looks promising so far.

I'm sort of having the problem sixshooter pointed out earlier, water is bypassing the radiator even when the thermostat is open, but this only happens when the water pressure is low (at low rpms). At higher rpms enough pressure is created that it cools very well. Around 3000 rpms seems to be the threshhold point, below that temps rise, above that temps fall. I think this will be cured with a bigger outlet on the back of the block. With more water flow I'm hoping it will force water through the radiator even at idle.

You need to use a normal sized radiator hose waterneck - like the one from the front of the head. I think your small outlet is causing the temp rise, and I'm surprised it's not causing rise at higher rpm. Why aren't you using a large cap/outlet/waterneck? :confused:

Sorry I didn't read your post before. Next time, shoot me a pm.

I'm not seeing the same results as you are. I don't face any issues with the temps when running at low rpms. My gauge will stay at around 190 degrees if I don't use the A/C. My temps will go up to 210 degrees as soon as I turn the A/C on; (2 days ago they went up to 220* while we tested the car for a little while) but won't come down from there.

When cruising in the highway I do find some airflow restrictions with my current setup but I'll be addressing that issue with a new Flex-a-lite dual fan kit.

I've also finally discovered that I'm going to need to do something with the hood. Heat can't escape the engine bay fast enough.