04Green

iTrader: (1)

@ huff...

On the orifice, with a lower flow (Remedy is lower flow, not higher flow) I lost some driver side heat in the winter, like most of it. That was at 35 degrees F. I think I will be going with a a small ball valve, with a pin hole drilled through it to get a tiny bit of flow, then play with it in the winter.

If you do not have the orifice installed, you are losing a ton of cooling. My temps without it were 10 degrees higher than with it (IIR). Any water that flows through that hose does NOT go through the radiator.

Nisaja

https://www.rx8club.com/series-ii-te...2-only-186066/

This thread says that it's only on S2s.

I had a fan diagram of the S1. Can't seem to find it. It didn't mention anything about high engine compartment temps. I'll try to look for it once I'm home.

hufflepuff

Wow, I was doing the heater hose orifice to treat the funny noise that comes from the glovebox at high rpm... did not know it significantly impacted engine cooling. Perhaps I could just remove it in winter and reinstall in summer.


BTW, do you recall which way the taper on that brass orifice faces?

Brettus

iTrader: (2)

As someone mentioned earlier , S1s often have the fans keep going once the engine is turned off . What triggers that is a mystery to me but one those two temp sensors i mentioned could have something to do with it . It is most likely the coolant temp. sensor but I have to say I've never had it happen on my S1.

9krpmrx8

iTrader: (46)

Mine does it.

Brettus

iTrader: (2)

Ever tried to figure out what triggers it ?

9krpmrx8

iTrader: (46)

No but it has always done it, even before I messed with the fans settings VIA the Cobb. And if you start the car again and turn it off again the fans still run so I assume it is running purely off of some temperature reading. My FAL fans are just wired to the stock wiring. I have a FAL fan controller, I have been meaning to install that.

Nisaja

On a stock car, if the fans have gone into high speed only because the coolant temp went over 213.8F, they'll stay on for precisely 5 seconds after turning off the engine. It doesn't actually have to be above 213.8F for the fans to stay on. Say as you were pulling into your driveway the temp went over 213.8, and that triggered the fans to go into high speed, and say when you were turning off the car, the coolant temp was 208F. The fans are still on high speed because they won't go back to low speed until the temp drops to 206F. So if you turned off the car at 208F, they'l still run for 5 seconds. Basically, if you turn off the car WHILE the fans are on high speed, they'll run for 5 seconds after the engine is off. Doesn't ALWAYS have to be above 213.8F. Same story when they're on low speed. If the fans are on low while turning off the car, they'll run for 5 seconds. It's just that it's harder to hear. Now if the fans were on high (or low) because you were running the AC, and the coolant temps aren't over the fan trigger temps, they'll turn off immediately as you turn off the engine. That's how my car works.

The posts from 2004 are about the fans staying on for MINUTES. Sometimes even up to 30 minutes! And I think that is because the coolant temp was over 230F. Because "high engine compartment temps" was added to the After Cooling mode only in S2s.

So that means the only reason they stayed on longer than 5 seconds, was because the coolant temp was over 230F!

And that means almost brand new cars hit 230F with perfect cooling systems.

AND THAT MEANS 230F was REALLY considered to be normal by Mazda!

I mean cmon... They must have caught it while hot weather testing it...

9krpmrx8

iTrader: (46)

According to the factory service manual, 243F is the limit before it's considered unsafe.

Nisaja

Yeah I remember you mentioning this multiple times all over the club.

Looks like 220F isn't harmless after all...

Someone should really change the "New and potential owners" thread. It clearly says that 220F is dangerous. IMO it's misleading people. Already misled a lot of people... including me.

04Green

iTrader: (1)

@ Huff,

Sorry, do not know which way it goes. Is a PITA to put in and pull out. I think a ball valve is in my future. I have seen pictures of them back by the washer bottle. Most have a handle that can be removed. I plan on a small hole drilled through to keep coolant flowing, but at a very reduced rate.

9krpmrx8

iTrader: (46)

Well, to fair, there is not a lot of trust in Mazda. My builder, Rob at Pineapple Racing told me that he builds a good amount of Renesis engines and older 13B's for use in sand rail buggies and he says that what he has seen from them running in the desert at high RPM, is that any extended amount of time at 220F will cook oem coolant seals. He offers heavy duty coolant seals of his own and that is what I have in my engine. Most builders I have spoken too also think 220F is the beginning of the danger zone.

RX-Tuner

What Mazda considers "acceptable" for street cars and what is actually ideal for an engine are not exactly one in the same. 243f is right at the point of catastrophic engine failure, especially under load. It may survive running around on the street, but it is weakening the water jacket seals as it occurs.

Nisaja

Fair enough. But on another thread you said plenty of people around the world drive these cars in hot weather, with stock cooling systems, going past 220F, and they're still fine

Brettus

iTrader: (2)

This is true . I've seen a turbo 8 run numerous laps at 250f and live to tell the tale . I've also seen a stock 8 sit in traffic with faulty cooling fans blow the coolant seals within 20 mins. I've run my own turbo8 at the track at that 220 level many times with no harm done as well.
While you might get away with 220F , running it there continuously is not optimal and introduces extra risk that is best avoided.

04Green

iTrader: (1)

One thing that some builders do is go a bit past the clamp torque on the keg. This keeps things from moving, and makes life easier on the seals.

9krpmrx8

iTrader: (46)

Yeah going past 220F and hanging out there are two different things and each 8 is different. But really we worry too much I think. Most other cars deal with higher temps in just normal driving conditions. My 335i's oil temps sit right at 240-250F in this heat (100F typically everyday) and my coolant at about 215F and that is normal. The fans on it and the electric water pump also run after the car is shut down until temps drop.

But this is why changing fluids is so important. Max temps are important but how fast your system can recover from those temps is more important.

Legot

iTrader: (1)

That's literally impossible.

Nisaja

Haha you're definitely right. We do worry too much about this. How long do you mean by hanging out? 1 hour? There are plenty of RX-8s here with stock cooling systems driving around in traffic. Pretty sure they sit in the 226F range. A typical traffic jam over here lasts for an hour. Those cars are still fine! And I'm over here in my RX-8, roasting my *** with the heater on whenever I see the temps get close to 220F

MagnusRacing

iTrader: (2)

I agree about the 220F issue. Racing for an extended period over 220F does kill coolant seals. I've lost coolant seals twice on stock motors (original motor and new factory motor). But never on motors with the "upgraded" coolant seals that Pineapple and other builders often use. If rebuilding a race motor always use the upgraded coolant seals.

vcoil

I'm really concerned about temps after my first engine change (2010).
I've a remedy water pump, samco hoses since and tracking with Tamb at 75+F was 215+F on Wt and Ot on Prosport gauges, sometimes 230+.
Installed a modified right oil radiator and the Remedy thermostat : Tamb 65-70, the Cobb Ap said 195-200F (As the Prosport).
Gain? Maybe.
If the car is track used I don't think the fan modification is something interesting. Maybe removing a fan will be more effective.
In my opinion the question is not only to let the air in, but to evacuate too...
I was conducting some aero test on the bonnet surface, but I don't have the under-bonnet data yet.

Maybe I'm wrong.

hufflepuff

I asked a trick question. The heater hose orifice is tapered on both faces, so it doesn't matter. Mine installed quite easily in the correct end of the hose (closest to the engine.

ion_four

iTrader: (1)

I bought the RE-Medy thermostat because it opens further, not because it opens sooner. My cooling system consists of a new Koyo OEM style radiator (bought right before they allowed larger rads in STX, doh!), RE-Medy thermostat and Evans Waterless coolant.

Evans coolant is known to raise the operating temperature a bit, but the boil over point is 375F, so there is essentially no chance of overheating or having localized boiling which is supposedly an issue on these engines.

With that being said, in 115F ambient temps, I did some 0-60 runs, drove in slow traffic speeds a bit and idled in front of my house for a while. I never saw operating temperatures over 210F, which I think is pretty good for being just about as hot out as anyone could expect. When it's 100-105 out, I still see cruising temps in the 17X-18X range.

So, I'm pretty happy with the cooling system at this point.

9krpmrx8

iTrader: (46)

And with a stock thermostat you would see the same results.

Legot

iTrader: (1)

No it doesn't.