Cooling a Lemons car

So our lemons car (rx7) has a bit of an overheating problem. During a race it "looses" enough coolant that eventually we have to stop, let it cool off and then add more water. I would like to fix this as cheaply, and simply as possible.

It is not leaking water, and it doesn't seem like it leaking into the combustion chamber, so I am guessing it mostly evaporating off.

I was thinking that if we had a large reservoir, we could run the cooling system unpressurized and just refill the water like we refill gas at the pit stops.

I am sure a number of you yahoos have tried this, Are there any pitfalls I am overlooking?

just rename it "old unfaithful" and let it go?

If you depressurize it, it will boil at a much lower temperature, of course.

On the roof.

Duke wrote: If you depressurize it, it will boil at a much lower temperature, of course.

Of course, I am thinking if we have enough capacity not to run out of water between pit stops, do we really care if it boils?

I would have to re-plumb a few things in order to get a reservoir to gravity feed into the radiator, but that's pretty easy.

I am a little worried about how rapidly we will use water (how much capacity should I add?) , or if there are some problems with boiling the water that I am not considering...

I'd jack up the pressure - you can get 21 psi caps - so it doesn't boil. If that's not enough you can just tap it and insert a bolt to have it make whatever pressure it has to...

Water doesn't just go away. It boils off and comes through the cap, or it leaks somewhere. If it leaks into the combustion chambers, you should rebuild your engine while you still can. If it is leaking externally, just fix it.

u dont wanna boil it. boiling it it may stop circulating

Capt Slow wrote: or if there are some problems with boiling the water that I am not considering...

you mean besides dumping water on the track for the guy behind you?

pressure test your coolant system, then leak down, find the leak (if it can be found cold), fix, run, enjoy. If it's a cracked head or failing HG you can get the symptoms you've described, but it's tough to nail down until something lets go...

Didn't motoriq add a little pressure valve on the top of the radiator cap on their miata and just use a old garden sprayer pumped up to keep it under pressure when they filled.

Do a coolant system pressure test and find where the coolant is going.

bigger radiator with a bigger overflow tank and longer hoses.. add as much capacity to the system as you can.

Just a quick question:

Did you guys do anything like a "rats nest removal" (like this)?

If so I had overheating problems when after performing step #22. A friend of mine (who also did a rats nest removal) ran a hose from the rear cooling hose to the front and had no issues.

Otherwise... remove the heater core and replace it with a B.F-ing water tank... when it started to overheat just turn on the heater and use the tank to recharge the cooling system?

Our LeMons RX7 (a 1st gen) doesn't even have a fan. We never see above 200 F on the gauge.

If water is leaving the system, you have a problem! It is not just evaporating. It is either in the combustion chamber or getting pushed out of the system.

Take the cap off of the radiator and run the car long enough to open the thermostat. Look at the water in the system. If it is bubbling and getting pushed out, you get to rebuild your engine. YAY!

What exactly is the problem? Gaskets are cheap. Radiators are cheap. Water pumps are cheap. And the sanctioning body will not penalize you for fixing parts and systems such as cooling. They penalize performance advantages, not basic maintenance.

Of course, the cheapest approach is to just park the car on pit lane and spectate. Maximum Seat Time is so much more fun that pinching pennies.

Just making it clear that you CAN pass tech with a shiny new radiator in place. LeMons and Chump both want you to finish the entire race, take the checker and come back for more.

Fix the cause of your problem, not the effects.

wearymicrobe wrote: Didn't motoriq add a little pressure valve on the top of the radiator cap on their miata and just use a old garden sprayer pumped up to keep it under pressure when they filled.

Yes they did, I just recently read that article. Sounds like it may be the easiset solution:

http://www.motoiq.com/magazine_articles/articletype/articleview/articleid/883/technobabble-how-to-fix-a-headgasket-with-a-garden-sprayer.aspx

Here's Team Eyesore's method of recharging the cooling system without releasing any pressure: Linky.

Doh....eastside was a touch quicker on the trigger.

eastsidemav wrote:

wearymicrobe wrote: Didn't motoriq add a little pressure valve on the top of the radiator cap on their miata and just use a old garden sprayer pumped up to keep it under pressure when they filled.

Yes they did, I just recently read that article. Sounds like it may be the easiset solution: http://www.motoiq.com/magazine_articles/articletype/articleview/articleid/883/technobabble-how-to-fix-a-headgasket-with-a-garden-sprayer.aspx

And LeMons-proven: http://www.motoiq.com/magazine_articles/articletype/articleview/articleid/1806/technobabble--the-garden-sprayer-that-won-2-championships.aspx

It's probably burning off through an ancient coolant seal. And the conventional wisdom when I had an RX-7 was to put Alumaseal in it and call it a day. (Assuming you've verified the rest of the cooling system.)

However, my next stint out with the Lemons Civic will include the bug sprayer mod. Thanks for posting!

Yes they did, I just recently read that article. Sounds like it may be the easiset solution:

http://www.motoiq.com/magazine_articles/articletype/articleview/articleid/883/technobabble-how-to-fix-a-headgasket-with-a-garden-sprayer.aspx

That's just too funny. It's the latest cooling system advancement:

Dynamic Interactive Pressure Supplementary Human Injection Technology

I am not too keen on rebuilding the motor at this point. I would be really happy just to get one more race out of this car. I love the motoiq system they came up with for adding water to the car while it is pressurized. That solves so many headaches!

That is exactly why I came here! you guys are awesome!

JtspellS wrote: On the roof.

Sadly I had to resort to this in my first Lemons race.

a quick disconnect would keep you from getting burnt too