Coolant Type and Quantity

[Pasha Saleh]

What do folks recommend for coolant? The green stuff or something more exotic? 100% coolant or diluted? I have heard it cools better when mixed 50/50 with water.

Also, what is the approx quantity? I am using a Dart 302 block bored to 363 with the standard RCR aluminum radiator, 2 quart expansion and 2 quart recovery tank.

 

[Skip Markley]

I use traditional Prestone 50/50 mix and have had no overheating problems. 427FE with 12.5:1 compression. I highly recommend filling your system using a vacuum filling device. Pull vacuum and check to be sure it holds vacuum (no leaks) then simply open a valve and suck the coolant out of a container (I use a large pail). This eliminates the air pocket issue that is common with mid-engine cars like GT40's. Quick and easy.

 

[Neil]

There is a characteristic of ethylene glycol that is largely unknown by most people- it is flammable. It can be ignited if it is in a fine mist. This has happened in a race car. The chances of this happening is remote but I thought I'd mention it.

 

[Howard Jones]

Most GT40s with a V8 take about 3-4 gal to fill from a completely dry system. I buy 2 gallons of antifreeze and two gals of distilled water, mix together in a five-gallon clean container, and then pour it back into the four containers it came from. Antifreeze brand is your choice unless you need something specific like pet-safe antifreeze or have a personal preference but basically, they are pretty much the same and do the same thing.

You can buy distilled water from the grocery store in the baby food area. It's really cheap.

As far as bleeding the system of air, that subject has been covered at length many many times in this forum. If you search " bleeding air from coolant system" or similar wording you can read all that is known on the subject, The short answer is a well-designed self bleeding system and placing the surge tank as high in the car as possible.

I like this stuff..............guess why.........

 

[Neil]

Howard, the anti-freeze isn't bad, either!

 

[Kyle]

Distilled water only and water wetter. Never gets below 45 here tho.

 

[Pasha Saleh]

2 gallons of antifreeze and 2 gallons distilled H20 it is! Old school green antifreeze or the pinkish/orange stuff you see in new cars?

 

[Brian]

You do want to use antifreeze for it's corrosion inhibitors even if it doesn't freeze in your area.

 

[Chris Kouba]

I like this stuff..............guess why.........

Howard- I didn't realize you were a mountain climber too!!!

 

[Liam39]

Another vote for Water Wetter. I live in a hot climate where maximum cooling is more important ant than anti freeze.

 

[Kyle]

The reason I went with primarily water, is that I was constantly draining and refilling my system. Chasing leaks, having to disconnect hoses, removing and reinstalling thermostat etc. I’m finally to a point where I’m comfortable with the car, but I wouldn’t have wanted to capture all that antifreeze everytime.

 

[Ian Anderson]

Something to check. If you plan on track driving the car, some do not allow antifreeze as any spills cause the tract to become extremely slippery.

Ian

 

[DaveC]

Remember, straight distilled water will cool your engine better than antifreeze, so never run 100% antifreeze. Antifreeze is obviously needed to avoid freezing and cracking your engine block among other things, but also prevents corrosion of the system. Adding a bottle of Water Wetter will increase cooling efficiency.

 

[Pasha Saleh]

Thanks again!

 

[Howard Jones]

Ian is correct. The antifreeze will not evaporate and leaves a slick on the track. It can be an issue to clean up. This takes up valuable track time and may cost you for the cleanup. This is why some track groups ban antifreeze when the car is run on the track.

I did a little test on my driveway and found that about 25% antifreeze didn't really cause much of a mess and on a hot day was pretty much dried up in an hour or so. I do run a couple of quarts in my 2-gallon fill in my SLC track-only car to help with corrosion.

My advice on waterweter is if you just can't solve your overheating problem any other way then go ahead and use it. Most overheating problems can be solved with a good self bleed system, serviceable and properly sized radiator, and proper ducting. Street-driven cars will also need adequate fans.

Then there is the whole subject of electric water pumps and their inherent advantages over mechanical engine-driven water pumps.

Oh and Dave is correct also. IMHO the best coolant is clean mineral-free water. But the corrosion problem should be addressed and that's where antifreeze comes in. In a climate that does not freeze, I think something like a 1/3 to 1/2 antifreeze is going to work pretty well in most cases.

Never run 100% antifreeze it just doesn't transfer heat well all by itself.