[Vaark]

Well, here is how it went down. On the track Friday 6/13 hi rev then boom coolant on windscreen. Hand out the window, drove around to exit track. Temp never got hot until I exited the track, then when I was really slow it started to rise. Cut off engine and coasted to parking.
Coolant pouring out below the radiator primarily on the left side (driver's). Trailered it home now it's up on jacks.
Pulled the appropriate panels could see no leaks but couldn't see where the lower radiator hose connects with the radiator. It's way up under the clam. Filled it up, started it and it again was leaking on the left. Turned off the car at 210d, the fans never came on and the lower hose never got hot.
That's where I am. Need all you guys experience. Pls.
I think key is coolant on windscreen.

 

[LotusCC]

Just had the Sector111 single pass installed while the clam was off for oil line recall. Went with the single pass over the triple after reading numerous threads and taking the advice Phil had posted.
Had a track day 2 weeks ago in 86 degree weather and temps were fine with no issues. Advanced run group.
If you have the stock rad with plastic end caps, I'd strongly suggest replacing, especially where you track your car. You don't want to find a wall at 100+ mph or have the guy behind you find that wall.
http://www.sector111.com/parts/performance/engine-and-engine-electrical/prorad-fp.cfm


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[Senna's Dad]

This is almost exactly how my 2008 240S cooked the engine one hot day on a SoCal freeway.

 

[Vaark]

I'm sure that is good advise. So, yea, will probably have to pull the front clam?
Since the coolant got on the windscreen and the engine had not gotten hot, I can assume it was a rad failure? Then to really check that I will have to pull off the front clam? Doesn't look too hard to do.

 

[Senna's Dad]

Yes, I don't think it's a good idea to have plastic and metal parts in the same part together holding fluid under heat and pressure.

 

[LotusCC]

Clam off. Even if it were just a hose/clamp failure, I think it would be prudent to replace the stock radiator and hoses.
I would have done it myself, but the clam was off at the dealership and they did a great job. Put in the Sector111 SS brake lines as well. Looks like it's a much easier job with the clam off, so.......
I had my brake pedal go straight to the floor at 125 mph going into a 90 degree turn deep into the braking zone. Wasn't good? and made me think I should change fluid for EACH track day and upgrade the lines.


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[Nessal]

I've seen many radiators in other cars with plastic end tanks and never a problem. Is it just because the supplier is crap for these cars?

 

[LotusCC]

Mostly because the majority of cars are set up with suspension that soaks up bumps in the road. Our cars are generally not set up that way. I've also seen plenty of "regular" cars have end cap failure, including two cars that I've owned. Usually starts as a slow leak. You smell it before you see it. IMHO, if you're tracking the car it's more of a safety thing. Like upgrading toe links and oil pan.


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[jefrac]

I had a tiny drip of of coolant at the end of a track day last year. You could just barely smell it. I immediately replaced it with a ProRad single pass. If you are going to push any car hard on a regular basis, it just has to be maintained with an open check book. Like others have said, not worth the risk on cooling, oiling, suspension, wheels, tires, etc.

The clam is really not that hard. It is a step-by-step process with good instructions, about like the most complicated thing Ikea sells. You do need 8mm and 10mm articulating head ratcheting wrenches and a few hours.

 

[Vaark]

Thanks. I guess I won't know what exactly failed until I get the clam off. Then looks like there is a shroud that also needs to come off?

 

[XHILR8N!]

A lot of us put a Prorad or similar in when the oil line recall was done. I went with the triple pass, no real reason why over the single, that's been discussed a lot.

I'd been getting just a few spatters of coolant, steam, a little smell.

You will enjoy holding that all alum radiator in your hands, it's "a nice piece of kit" as the Brits say.

 

[yellow99s]

Went with the triple pass as well after noticing a light mist on the windshield, it's an easy enough install, the hardest part is bleeding the air. If you haven't done the blower resistor pack upgrade, I highly suggest taking care of it at the same time.

 

[Vaark]

Thanks. Will checkout the blower resistor pack suggestion.

 

[holmz]

...
You don't want to find a wall at 100+ mph or have the guy behind you find that wall...

You would make a good preacher or insurance salesman.

The OP really needs to figure what failed before "fixing it". It might just be a hose. That said, it does not hurt to have a replacement in mind.
But the alloys fail as well.
A lot of advice comes across as without a new radiator and brake lines you are going to hit a non existent brake peddle and go into the wall.
In reality these upgrades are only upgrades if something is improved, or at least fixed. So a brake fluid change may be more usefull than SS lines for a lot of people.

Pull it out and see what has failed, or test it in-siut with a pressurized cap tester.

 

[<@¿@>]

In situ pressure test won't tell you if it is radiator hose, radiator, heater core or just a hose clamp...just that your cooling system is no longer air tight. To diagnose, you will need to pull the front clam off. There are two screws (socket head cap) at the base of the A-Pillars that only be gotten to from an open door and under the head lights that only be gotten to by removing the headlights.

As stated before, it would be prudent to upgrade your radiator to an all aluminum one. Sure they fail, just like anything else mechanical...its just that the all aluminum failure rate is probably 1/10 that of the plastic/aluminum one. That's a no brainer for me.

Also, do you realize that the Lotus engineers speck out the triple pass radiator for all of their motorsport cars and all cars that go to the middle east? It is also the same triple pass radiator that is used on the V6 Exiges? And you would go with single pass that was recommended by a mechanic? :facepalm

 

[LotusCC]

Also, do you realize that the Lotus engineers speck out the triple pass radiator for all of their motorsport cars and all cars that go to the middle east? It is also the same triple pass radiator that is used on the V6 Exiges? And you would go with single pass that was recommended by a mechanic? :facepalm

No, I did not realize that?
I read a lot of threads on that before I plopped down the $.
It worked great at the last track day, but had I known this information before purchasing, I may have reconsidered.
Does it matter if the car is NA vs. FI?


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[holmz]

NA means that it is not turbo or super charged.
FI means that there is no carburetor.

The Middle East and perhaps driving slow makes "a triple pass" sensible. There are also good arguments for a single pass.

Pressurizing the system "can" show leaks. Some of those leaks are hose clamps or other things that are not the radiator. While I would likely consider doing the radiator I also recognize that that may not always be the wise decision.

And the approach of making one feel guilty for causing a crash, and/or suggesting that one will hit a wall at 100+ I find offensive to people's intelligence.
I would suggest finding out what the issues is, and then weigh up the options. I am betting in the radiator, but I would not doubt a hose clamp.

 

[enderw88]

NA means that it is not turbo or super charged.
FI means that there is no carburetor.

Or, "FI" means "Forced Induction".

 

[<@¿@>]

No, I did not realize that?
I read a lot of threads on that before I plopped down the $.
It worked great at the last track day, but had I known this information before purchasing, I may have reconsidered.
Does it matter if the car is NA vs. FI?

Heat transfer is a dynamic state...that just means that lots of thing are changing at the same time...and makes the problem that much more complex.

Now think about it...heat transfer is a rate. With a certain amount of temperature differential, you will get a certain amount of heat transferred. Hot water comes from your engine and flows across the radiator from left to right and from to to bottom. Now...keep in mind that hot water is less viscous than cold water. So the water just flow across the top of your radiator...also a very short distance and therefore a short length of time. Now if you force the water to go back and forth across the radiator three times...it forces the water to be in that radiator a longer time and therefore cools the water down more. The only reason you would not want the water to go through the radiator three times, is if you are are running water at such a great speed (volume) that the surface friction restricts the flow rate...but that reduces the amount of time in the radiator!

Any way you look at it, it's a loose, loose situation for a single pass radiator.

If you are not overheating, then all is good. I wouldn't swap out a single pass for a triple pass if I already had a single pass in the car...unless it was overheating.

 

[turbophil]

The single has been tested against the triple. Volume becomes the issue with the triple at high RPMs with big HP cars on the track It's like this: Take an 11" tall rad and slice it into 3 tiny radiators and you have just significantly reduced the volume able to pass through it with a water pump spinning like mad that needs all volume relief it can get. Result=cavitation. At "most's" low power levels, either will work obviously. When you start pushing it, many have gone back to a single when they found the triple wasn't keeping up... and guess what, temps came back down. You need water volume to cool down horsepower. It's critical. Now, you might be able to make a little triple pass work better with a bump of bypasses, but what's the point when a single is available... and for less money! :clap:

Comparing to the V6 Exige that is a road going car running at a much lower RPM and still only generates 345hp to a high hp track car with a strung out I4 isn't fair. That V6 is no big deal and easy to cool. I race with a V6 Exige (conversion car). It's a SUPER easy motor to cool. They have the front taped down to 50% on 90 degree days. Those big motors just lope along with silly low output per litre, etc...

Now, conversely, try cooling off 400+hp on a 1.8L motor that spins to 8500rpm and stays on average between 7200-8500rpm where the horsepower is being generated... That's putting heat into the system that the low volume triple pass rads can't handle. I don't need a calculator for this stuff, as I have ran them all...

-Mechanic.

PS- I'd add that if you really want to do a good job of getting heat out of the engine and into the air, pressurize the cooling system for a more efficient transfer of heat in the first place. That works even on lower output motors...