RX7 8U

iTrader: (1)

Hey Adam - yours runs cooler cuz it's white. My MB sucks up more heat. How's that for an answer!

juliof

You might have air still in the cooling system, make sure the Miata switch is working it should kick fans on at 207F it dosent sound like its working if temps are so high.If not youre stock fans will turn on at 230F no matter what size rad you have thats when fans come on.

Marcel Burkett

I am still using the stock rad . with no problems never going above 190deg F although I havent gone to anything more than 8 psi boost . One thing you can check is the actusa speed of the fans , I once noticed An increase so I checked my system , what I found was, although the fanS were operating properly , one was actualluy Turning slower than (usual) THE OTHER , I had an electrician check it and he said that the brushes in the fan were finished , so I replaced the fan and the temps went right back down.

James Paventi

iTrader: (34)

Well guys,

I've put way too much time and money into this motor rebuild to risk that my radiator isn't doing the right thing. I've just ordered a new Koyo. When I've had a chance to put it in and drive a bit, I'll let everyone know. I'm guessing it'll happen just before Seven Stock.

If I'm wrong and then temps don't go down, then someone's going to get a perfectly good (about 3000 miles old) Fluidyne, cheap.

Take it easy all,

James

Hey ... I just received an email from http://www.carradiator.com saying that the radiator will be on my door in two days! … I may have it in this weekend.

RX7 8U

iTrader: (1)

Just got back from SevenStock and after talking to some folks I think my problem is the radiator. I would like to put the stock one back in to compare. If anyone has a good stock radiator in the Sacramento area I could borrow for a few weeks or buy please PM me. Thanks.

Donovan

Same problem here My car is running hot and there is no reason for it. It just started to run hot. Newer motor, no cats to clog, all new coolant hoses at rebuild, no visable coolant use, Now the car runs like crap so I hope it's not blown again.
I'm going to pull the thermostat out and check it. Is it possible to run without the tstat in place? I've never pulled mine so I don't know if it will seal without the tstat in the car.

James Paventi

iTrader: (34)

RX7 8U,

It was nice meeting you at 7 stock. I noticed that you drove down with Adam. I think that I see the real cause of your problem. It's the "cheap bastard" air shield that Adam sells. Is there one in your car? There's one in mine and I'm quite certain that it's the reason I'm overheating! It's blocking the airflow ...

Just kidding Adam. Don't worry, your air shield is one of the best mods on my car.

Anyway, I just wanted to let everyone know that I removed my Fluidyne and installed a Koyo. There we're some obvious differences. The Koyo is about 1/4 an inch thicker, half and inch longer and the aluminum crossing between the water passages is packed considerably more densely than the Fluidyne. Oh, it holds about another 1/2 a quart of coolant. The only bad thing is that the Koyo isn't anywhere near the perfect fit that the Fluidyne was. Also, the original radiator mounting wings are required. Anyone have a set for me?

Obvious observations aside, the car is running cooler. I've had one or two more of the close to 100 degree days (hey, we're talking so cal here). I managed to push the car to about 230 going up my usual testing grade at about 70 MPH with the A/C on. I was boosting as much as possible. Considering that the Fluidyne would rise to 240 without any boost, this is a big improvement.

I'm still not convinced that the Fluidyne has a problem. It worked so well with regular water and coolant (I'm now running Evans) that I suspect the combo of Evans and Fluidyne. I may offer the radiator for $275 with a thirty day return policy. If it doesn't do the job, bring er back. I'm just curious to see what happens. Well we'll see, I may just return it to Fluidyne given that this may be an engineering defect. There are just too many stories on the forum.

later all,

James

cavellm

Ahh, Fall is upon us.

I'm now in the days of 82c water and 39c intake temps.

And life is good.

cpa7man

iTrader: (2)

Cavell what rad are you running?

All this talk about Fluidyne's running hot has me worried. James and few other people have chimed in. The guys at Gotham tell me the Fluidyne is a much better radiator, but 1/2 a quart is a lot more capacity.

adam c

iTrader: (2)

I have a fluidyne, and it works fine. It fit good, with no problems. It sounds like they sold a couple of bad ones. I suspect that they will refund money, or replace the radiators in question.

The capacity of the fluidyne is more than enough.

cavellm

I've got a Koyo. Had absolutely no problems with it since I put it in last September.

This summer when temps were around 100F the max water temps ever seen was 95C measured by the Power FC. And that was sitting in traffic for about 45 minutes.

But regular driving around with ambient temps from 90F to 100F I'd stay between 88C and 92C.

For $100 cheaper than Fluidyne, I'd say go for the Koyo.

jeff48

After reading the whole thread I am still unsure of a fix. However, I may be able to shed a little light on the issue of "sealant". The sealant referred to is the additive ("bars leak" "StopleaK" "Alumni-seal" etc) left in the lines, heater core, engine core, water pump etc, from previous unsucessful attempts to cure coolant leaks. Every line must be flushed when installing new engines or radiators. Radiator tubes are notorious for plugging up with this gunk. If you are replacing your radiator, use your old radiator (after a chemical dip or rodding) to trap most of the residual sealant.

SpeedracerRX7

Just to let you know that there was no BARS leak or any other sealant put into the cooling system to help cure any probs that I had with the car. My engine blew previously from a broken seal and the radiator was in the car then and didn't have a problem. It was only after the engine was re-installed that the problems occured.

I can assure you that Fluidyne has replaced my radiator with a new one and now the car doesn't break 86 degrees even after it has been run hard. They cut my old one open and haven't been able to identify the substance that is on the inside of the fins but they can say definitively that it isn't any sort of radiator sealant. They say it looks like a ceramic sealant that may have been used when putting the motor together. Like I said they are not sure and they are going to continue to look into it. I'll keep you all apprised on the situation.

RX7 8U

iTrader: (1)

Almost a year has shot by already and I'm finally getting around to posting an update to this thread with my discovery. Fluidyne replaced my radiator no questions asked. They were very concerned about my problem. After putting in the new radiator I discovered my stock airbox was pinching the radiator hose almost shut! The fluidyne upper hose spout is not at the same angle as the stock radiator. It causes the hose to sit too high. So when you bolt down the airbox , it pinches down on the hose and cuts off flow. So, I left the airbox on loose enough so it doesnt pinch the hose anymore and now my cooling problems are solved. I recently got a PFC and the highest temps I get now are 94C driving hard up a grade on a hot day with the a/c on. Much cooler than it ever ran before. So, there is no problem with the fluidyne cooling wise but there is a problem when using a stock airbox. I'm sure this is something everyone should watch out for when mounting any aftermarket radiator.

But, now on to my new problem......a major one. After all this trouble an engine O-ring just let go. It overheated too many times I guess plus now running 12 psi boost with the new PFC was probably too much for my 'ol 80k mile engine.

alberto_mg

sounds like the radiator isn't installed correctly. I have a Fluidyne as well with the stock airbox and my hose is not pinched at all.

pomanferrari

iTrader: (1)

My Fluidyne isn't pinch by the Rotary Extreme airbox. However, the upper pipe has some weird angle to it.

RX7 8U

iTrader: (1)

It's installed right. Maybe some fluidynes production runs have that weird angle "pomanferrari" mentions and maybe some don't. Maybe the welder had a bad day...who knows. But I definitely gotta as pinch. The pinching spot is at the end of the upper spout. The box pushes down on the hose at that point causing an "S" in the hose and with the airbox bolted down tight it restricts flow. Just loosening the air box screws some relieved the pinch. Also, with a stock air box over the hose it is very hard to see where this pinching occurs. Everyone installing an aftermarket radiator should just check this area. You might have a pinch or you might not. That's just the nature of these beasts.

adam c

iTrader: (2)

I remember you telling me that you had to modify your fan shroud differently than mine. I guess that Fluidynes radiators are not all the same .....even though they are supposed to be.

You should get a new mechanic

badass7

Werd Cavellm, that's the temps I'm getting on my STOCK Radiator and PFS SMIC on cool days. Otherwise I'm at 85-87c in the hott *** daytime weather here in the N.O.

EFS.O

Hey man,have you checked the condition of your oil coolers?maybe thats the source of your high temps....

RX7 8U

iTrader: (1)

I'm resurrecting this old thread with another update.........I compared the upper spout on my Fluidyne to AdamC's fluidyne and they are different! My upper spout extends about a 1/2 inch higher than his which makes the radiator hose sit higher. This is why the stock airbox pinches down the hose on mine but not on AdamC's doesn't. Someday I'll post pictures of both to show the difference between these 2 Fluidyne's.

sevensix

iTrader: (1)

mine pinches a bit on the upper hose too.

scotty305

iTrader: (2)

Interesting stuff, thanks for the update.

-s-

tphan

Before the PFC tune my Defi temp gauge would read 210-220*. With the tune gauge now read 200*, Commander read 95*, this was with AC on in 100* ambient temperature. Thinking about getting a SR Motorsport alum radiator for next summer.

Last week Dallas hit tripple digits 4 days straight...the 7 sit at home or sweat like a pig.

lilfreddie

rx7 8u did you ever figure out your problem? my car is doing the same thing!