rx7tt95

I'm having issues with what I believe is air trapped in my Fluidyne. I've switched to a front mount and it's now positioned vertically. Below is an account of what happened on the first night after the installation. I've been "burping" the system periodically and things seem to be getting better. Temps start to creep a bit but hold steady. I've not blocked off openings around the radiator (yet). One thing I've noticed today is that upon restart, temps are hotter after the car has sat for a few minutes. Nothing out of the ordinary. I'll get in, fire her up and the PFC commander will read something like 103 celcius. Temps will drop about 3-5 degrees and I get the car rolling. Thing is, they don't drop any further.

As long as I don't shut the car down and restart it, temps don't go higher than 93 celcius. But the strangest part is the fact that the driver's side of the radiator is still much cooler than the passenger's side. Below is something I posted to the big list two days ago...sorry bout the spacing, just copied and pasted.


I installed a front mount IC today and naturally, the radiator gets switched
to an upright, vertical position. After re-installing everything, I dumped
coolant/water/water wetter back in, as much as I could get, then started the
car and waited for her to heat up. Took forever. When the thermostat did
finally open, the car was already at about 100 degrees celcius as hot water
flooded into that section of the cooling system. It went from 30 degrees to
100 in about 2 seconds. I shut the car off and poured more coolant in.
Started her again, began to overheat and coolant boiled out. I shut the car
off again and capped the coolant fill. Started her up, started to get warm,
shut her down. I then loosened the cap again after letting it cool for a
minute or two and it gurgled and popped then seemed to settle down. There
was room for more coolant so I added a bit more, then capped it off and
started her up. No overheating, but running a bit hotter at 93 degrees.
Normal for me lately has been 87.

Here's where it gets strange. After driving the car around, it gets up to
98 or so. I pull back in the driveway, pop the hood and touch the
passenger's side of the radiator. HOT. VERY HOT. Touch the top of the
driver's side and it's cold. What gives? Do I have air trapped in there
causing only half of the radiator to be used? Now if it were a horizontally
flowing radiator I could see the above being normal but it flows top to
bottom. I now have mostly hard lines (as in tubular metal) for the two main
coolant hoses running to/from the radiator to the water pump. I can't
squeeze and burp it any longer. I did empty the entire radiator for the
installation and the car sat without coolant overnight. Any help or advice
appreciated!

CCarlisi

this past summer I installed a pwr rad and a greddy fmic. It took me about a week to get all the air out of the system. I also noticed that the temps would climb after the car was shut off. This lessened after I got the air out, but I think they are still higher than with the stock radiator. Maybe by mounting the radiator vertically it is not able to expel hot air from the top and pull cool air in from underneath as efficiently. This isn't an issue when the car is moving because air is being forced through it horizontally, but at a standstill I imagine it would make a difference

rx7tt95

It seems to get a bit better every time I burp it but I'd like to see my temps stay at 87 celcius. I'll be fully shielding the radiator next which should also help. At least I know I'm not alone :-) I just thought it was very odd that one side would be hot but not the other.
Michel

80-CU.IN.T

I suggest welding a small fitting for a air bleeder on top of your radiator. This is what I plan on doing to my radiator when I pull my motor to have a side seal replaced. I removed the radiator cap because of clearance problems. ( Pic below ) Also bleed your engine from the hose that connects to your fast idle cold start on your throttle body (I don't know the proper name for it) this seems to be the highest spot on the motor. I also drilled 5 holes (Around an 3/16") in the top of my thermostat flange to help in bleeding the air out and to help the motor warm up evenly.
If your turbo is water cooled the water can boil when you shut your engine off putting a lot of air in your system. I think that is why there is an AST on the 3rd. Gens. Don't know about other models. And I do prefer water cooled turbos. They seem to cool better and not coke up.

[IMG]radiator 3.jpg[/IMG]

80-CU.IN.T

AAHHHHHHH

80-CU.IN.T

Just shoot me -

Lost Time

Bang.....you're dead.

rx7tt95

I have thought about tapping in an air purge at the top of my tank on the "fat" end (passenger's side). I no longer have coolant feeding the TB and the turbo is oil cooled only.

Ran up to Clearwater today to have an elbow welded up to go from the FMIC piping to the T78 (GReddy USA couldn't provide me with one because they're asses) and the temps never got above 90 degrees. It was about 75 here today and I'm sure in summer, temps will get hotter. I think that if I get all the air out and seal the radiator, it'll be as good as the stock position and a SMIC, at least on the street.

Here's a pic of my nifty welded elbow courtesey of RaceRelated.com in Clearwater. Awesome guys with some amazing cars. I witnessed an 03 Cobra put out over 475hp at the rear wheels with bolt on mods. Too bad it weighs 3900lbs. If you're looking for parts, talk to Rich at Race Related. RX7 owner and a great guy to boot. They did the elbow for me on the spot. Looks pretty damn trick if you ask me!
Michel

rx7tt95

Just an update, I've now managed to burp the system enough times that I'm seeing "normal" operating temps of 87 degrees. If I shut the car off for a few minutes and turn it back on, typically the temps won't drop all the way down to 87, but to 90 for a bit then to 89. Otherwise, no overheating, even on the highway. And I haven't sealed the radiator yet.
Michel

fdracer

couldn't you have clocked the turbo differently to get less of an acute angle at that elbow?

rx7tt95

Nope. The GReddy cast elbow that's included in the kit is almost identical in angle unfortunately. That's the stock GReddy piping too and that's the area it's designed to go to. IMHO, the turbo's placement is not ideal on this kit.
Michel