Simple question but not for me....

How hot can you run a car on straight water?

(history): I built a Bucket over the last couple years and I'm having cooling issues. I have talked to alot of people and tried a lot of things and my last change on Saturday after Car Craft has been the best sofar. Car used to piss out water right when you start it. I have tried new caps, new thermostates, larger fan, made a shroud, electric fan pushing into the radiator from the front, had the radiator cooked and checked for flow, have changed jets in the carb to 101 primarys and 98 secondarys to richen it up and 1 colder on the plugs, also have messed with timing. Saturday I pulled intake to just look see again and decided to change water pump off a 305 I had for this project before I switched to the 350. I also flushed the block but the motor was in a truck and not having any issues and hasnt been sitting.

Ok, anyway I changed the pump and put everything back together. I put a 160 stat in and filled with water. Had to burp it out a few times but I was able to get it full and filled the catch bottle just because. Now the car doesnt piss it out anymore but it runs 210/215. I just dont know how hot I can run this thing without hurting anything. I was told you could run up to 260 with 50/50 antifreeze and a 15lb cap. I'm tired of wasting antifreeze so I would like to take it out and run it down the road with the water.

Any ideas guys that I havent covered other then a bigger radiator? That will have to wait till winter because I have to rebuild the front of the car then. I am running a 4core now thats larger then ones I saw people running at Car Craft without issues.

 

Might want to talk with these people -

www.evanscooling.com

Terry

 

if you wanna run straight water (obviously distilled) use a product called water wetter. it raises the boiling point of the h20 and thus keeps temps down. i swear by it and can attest it's no gimmick. i ran 2 seasons with water and this stuff and nooo problems. here it is for 10 bucks a bottle (roughly one bottle per radiator) http://www.pegasusautoracing.com/productselection.asp?Product=1699

 

old timers used bubble less soap (water wetter) and water soluable oil the soap brakes the surface tension so the water has more surface area

 

I would try watert wetter. I have run it here in Florida for 3 years and does will bring the temp down. I have never had a problem with it. I am running a 160 thermostat with an electric fan and have never got over 190 in the hot summer.

 

FWIW, you've probably answered your own question. If it's a T-bucket, you've prolly built more motor than radiator. Anyhoo, straight water transfers heat better than 50% antifreeze. If you are consistently running above 220, there is a cooling system engineering problem or a mechanical problem, such as ignition advance, compression. About all you can do at this point is check the ignition advance. Without knowing what your engine specs, run as much initial advance as you can, 14-18 degrees, vacuum advance at cruise and limit the total centrifugal to 34-36 degrees would be a typical SBF/SBC suggestion.

thnx, jack vines

 

You should be able to get it up to about 230 or so without boiling, with just water, and a 15 psi cap. You probably don't want the engine to get up to 260 anyways...230-240 is probably as hot as you want to get it so you don't hurt anything.

 

Try running the water pump faster. A lot of the aftermarket pulleys are matched to reduce the water pump speed for high rpm use. Depending on the rear axle ratio the water pump volume may not be high enough at cruising speeds. Look at the pulley sizes on trucks or full size cars, most of them run the pump faster than crankshaft rpm. The radiator should be used as the restriction in the system and always use a quality thermostat.

 

And again with the 50/50 antifreeze. Antifreeze is NOT a coolant, it is just what it says it is. Some have a weak coolant in them but it is only good for stopping it freezing.
You can buy anti boiling agents that are 100 times better than the combination stuff but...........
As others have said, water wetter and clean (distilled water) will probably be better for your application.
What are the differences between the water pumps you changed? Was the impeller on the one you took off OK or corroded? Are the pump pulleys the same size?
It sounds like the issue may be linked to the volume of water going through th radiator, too fast or too slow can cause it to over heat.
Now NM, I'm guessing New Mexico? If so it wouldn't get near freezing there, take the thermostat out and throw it. All they do is stop flow until the motor warms up, without it you will get better flow through the entire system.
Don't listen to the idiots that say you HAVE to have one, most of them say that the system was designed to have it, so have it. The problem with that is, the system it was designed for no longer exists. You have removed it all and built a new system.
Factory cars had them as the cars could be sold anywhere so they had to cover their bases for cars going to colder climates. It really is useless in a warm environment, just let it warm up a little more before driving.
Doc.

 

NM....MN.....not quite the same thing

 

Hang on, pissed water out ON START UP. Like when its cranking or when its warming up? If it is doing it while warming up that would point to air being in the system. Try filling it up with the front jacked up to ensure that the filler is the highest point in the system. If it still does it start looking for bigger issues, there could be somewhere that is drawing air into it. Head gasket, even look for small cracks in the block, anywhere you can think off.

Another question I didn't see an answer for, does it cool more when going down the highway and heat up at slow speeds or does it heat up no matter what?
Doc.

 

MN, **** I think Im getting lexdistica......

 

I am with Doc on the T stat. You no longer have the system so what ever it takes to get you going is just fine. I dont have T stats in any thing that a street rods. I make a restrictior for the upper hose to speed up or slow down the water flow. Example is my top hose is 1 1/2 inch so I purchase a couple of freeze plugs that size then drill one out in the middle at 3/4 inch hole and another at 5/8-I install it in the top hose and shove the hose on there by placing the restrictor at neck depth. I put a extra radiator clamp around it to make sure it wont flip add a little water and try it out. See what it does on the hi-way then stop and go. enlarge or reduce hol sizes as necessary and it will never hang like a t stat. Works for me.

 

What does running without a themostat due to engine life?
May not always cut it in half, but it will on short trips. Almost all the wear occurs on cold start, that's why truck engines are kept running. Discovered 75 years ago....
"Warming the engine up a bit" before driving is the worst possible thing you can do.
Start it, and drive it as soon as possible - just don't put any load on it until the gauge moves.

 

Make sure your lower hose isn't compressing due to suction. That's why they have a spring inside them. It can cut down on your flow enough to cause heat issues.

 

Well I have driven it for 2 short trips and it used to overheat before I got this far so maybe I got it by switching pumps. I used the same pulley I had on it before. With just water it is running about 215 now going down the highway and it doesnt seem to change much at any rpm. The top of the radiator with a temp gun shows 200 and the bottom about 180/185.

I have a 160 stat in it still and straight water. I have not pulled the old waterpump apart yet but I'm guessing it must be rusty ot something. I pulled the one I swapped off another motor. It has needed a few cups of water after each time I have driven it but it's not over flowing anymore.
It used to start trickling out when I first started the motor and when I shut it down. Not doing that anymore. I was looking at that EVANS cooling system sight (in above posting) and the fluid they have but at 32.00 a gallon I want to make sure I'm not going to be loosing it on the ground.

Will probably just go back to a 50/50 antifreeze because I'm going to need it in a few months anyway up here to keep it from freezing, well maybe 4 months. lol

I need to get it out and take it for a longer drive this weekend I guess and see what it does. My gauge goes to 250 and the needle is hanging around 210/215 right now.

If I run this and she dont leak out and it gets 220 will that hurt the motor?

Thanks for the idea's guys, it's been a stumper all summer sofar.

John

 

I ran straight water for about 6 months in my daily driver Ford F-150 here in Texas because I had a slow leak. I'd have to refill it about once a month or so. Eventually the bottom of my radiator filled with rusty mud, which made the truck overheat. I had to take it out and clean it all out. Took me about 4 hours on a Wednesday night.

If you've been running straight water for a while, do you think your radiator may be partially filled with rust? Will it be later?

 

Many millions of cars have been built that have been cooled by regular, everyday, boring, cheap water and anti-freeze. Pouring magic potions into the radiator is about the same as going to a faith healer.

The water wetter stuff makes some pretty bold claims. The only thing that I can see that it does is increase wetting, having to do with the surface of a multiphase system. http://en.wikipedia.org/wiki/Wetting Nevermid the fact that the coolant in the system is a single phase system, and there are no free surfaces. I know that asking for scientific third party testing is like asking for their left nut, but they are the people making the claims. If this stuff really works as well as they say, wouldn't places that need huge cooling systems use it by the tanker? Powerplants could save millions...

The Evans Cooling stuff looks to be pure Propylene Glycol, which has a lower heat capacity and lower thermal conductivity than water, which makes it a worse heat transfer fluid than water. The only advantage I see is the higher boiling point reducing "burnout" (actual technical term). Not worth the effort...

I recall a friend's car with overheating problem, turns out it had a pump for a late model, with the pump turning backwards.

When you say that it pukes on startup, I am thinking there is not adequete expansion room in the system. As the coolant gets warm (not boiling) it will get bigger and needs a place to go. That can either be an air gap in the top of the radiator, or in a catch can. A re-circulating recovery system will **** the lost coolant back out of the can when the car cools down. If too much coolant is lost, and the radiator is only partially full, its abilty to remove heat will be extremely diminised. Old fords used a tank above the radiator, that ensured that the radiator was alway full, and it seemed to wrok very well.

Pure water with a 15 PSI cap will boil at about 250°F. Too hot, really. You aren't hurting anything by running at 210-215, modern cars do it all the time. I do suspect there is some fundimental design problem going on though, because that is pretty warm for the combo you have. Very likely it is a lack of expansion space in the top tank, and could be fixed with a recovery system. Is the cap mounted at the very top of the system?

 

Drill a single 1/8" hole in the thermostat flange to bleed air forestalling an air lock.


I see you have a vacuum advance distributor.

Source the vacuum can to manifold vacuum and shoot the timing to make sure it's working.

You may have over 40* of advance at idle, but it's ok.

A lean A/F ratio at idle needs time to burn.


Simple stuff, but free and so far it's always worked....

 

I'd suggest running a good 180 degree stat. If it doesn't have a small by-p*** hole in it already; drill a 1/8" diameter hole in it. Running a 160 stat does nothing to keep the coolant temps lower. It just begins to open at a lower temp. Removing the stat completely can also cause overheating because the coolant will not be in the radiator long enough to cool down. If you decide not to run a stat, you will need to install some kind of restrictor in the radiator hose to slow down the flow. This would be a trial and error method.

If it isn't over-flowing, boiling over or blowing coolant out the overflow; then where do you think it is going? I suspect a blown head gasket or a cracked head or block.

Try this. On a cold engine. Remove the radiator cap. Begin to crank the engine over as if to start it. Did any coolant blow out the radiator fill? If it did; then you more than likely have a blown head gasket or a cracked head or block. This would also explain where the coolant is going.

The temps getting up to 230 degrees should be OK.

I'd suggest you do the simple test I mention above first. If all is well at that point, then I'd suggest running a good 180 degree stat, coolant that has no more than a 50/50 mix of water/anti-freeze (use the green anti-freeze NOT the tan environmentally safe stuff because it can gell up and clog the coolant system), a 16 lb cap (get it tested because many "new" caps will not hold 16 lb. pressure), and a coolant recovery tank. Your timing is also very important. Retarded timing can cause the engine to overheat very quickly. Use a solid fan rather than a flex fan or a clutch style fan. A shroud can be very helpful to better direct the airflow.

Where is your temp sending unit located? If it is in the cylinder head you can expect to see temp readings about 20 degrees higher than you would if the sender was in the intake close to the thermostat housing. This is due to the close proximity of the sender to the exhaust ports in the head.

 

wheres the gauge sensor? intake or side of head?

edit: oops, the post above me wasnt there a min ago! haha

 

No that is not how it works. Water Wetter reduces the surface tension of the water. This means that the water molecules are in more intimate contact with the hot metal, and so more easily transfer heat. You can achieve the same results by adding a few drops of dish washing detergent, and for a lot less money.

To raise the boiling point, you either change the liquids, or you raise the pressure of the system, or both. Since you are running pure water, then you have to raise the pressure.

If your cooling system cannot keep your engine under, say, 220 degrees F then something is wrong. Running higher pressures to 'cure' the problem is really just masking the problem.

Why are you running pure water, anyway? You really need the rust inhibitors and water pump lubrication that modern anti-freeze solutions provide.

 

Plain water needs a rust inhibitor and water pump lube added to it. Period.
I've met too many people in the midwest that came from "Cali" braggin to me about how they didn't need antifreeze back there.

Then i'd pop their cap and quote them a price to clean it out. lol. "Smarter" than the manual means they'll be comin my way.

 

a million years ago when I raced stock cars, we weren't allowed to use antifreeze (slippery when leaked), so we used a product called CoolIt, don't know if it is still available but it was worth a 25 degree drop, It was illegal too, but it was colorless and got by the inspectors easy.

 

please change your avatar...man thats creepy

 

Well to answer some of the quick questions: I'm running straight water right now while I tried to fix the problem. Getting kinda spendy puking antifreeze and making a mess in other peoples driveways, water dries up. lol I am going back to a 50/50 here shortly if it holds like it has been. It stays right around 210/215 right now with a 15lb cap and water. I have an overflow tank and it's not overfilling out of that anymore either. I'm pretty sure the water pump was the issue and swapping it with another seems to have done the trick. Funny thing is it worked fine in the truck but it had a lot larger radiator and a heater core to cool with.

My filler cap is on my intake about 5" above the thermostat on the housing and higher then the radiator. I do have to burp out the top hose and after I run it and let it cool and I did it again just to be sure.

My plan is to put some miles on it this coming weekend and see how she does. If it holds like it is I'm going to go back to antifreeze and be done with it I hope. Then I can move on to the darty steering issue but first I have to get bias front tires on it.

This is the first car I have built from scratch. I have done plenty of motor swaps and things like that but never drug a rusty body from a field and built a frame and car out of it. Was and is a learning experiance.

Thanks for all the idea's guys. Sometimes it's great to have others to check into.

John

(oh and who is afraid of PennyWise the Clown?)

 

One other thing you may want to do, verify your temperature gauge is accurate.

Get yourself a candy thermometer at the cooking store.

Open the radiator cap part way so the radiator isn't under pressure when the engine is warm.

Fire the engine and let it come up to temp.

Check coolant temp with the candy thermometer and compare to your temp gauge.


Candy thermometers come in two styles, one is all gl*** like a typical thermometer and the other has a steel probe and steel encased dial - very similar to a meat thermometer, but it has a higher scale.

Dad used to have a gl*** one, took good care of it and little brother uses it to this day.
Mine is a steel one and storage is easier....

 

Yeah I have checked and it's right. Also have a temp gun. My gauge sender is in the housing right above the thermostat.

The drive this weekend will let me know and then I will go back to antifreeze and drilling a small hole in thermostat for vent.

John

 

If you are running a 160 thermostat and your motor is running at any temp over that, then you DO NOT have adequate cooling capacity.

If the water pump is ok, and the thermostat is ok, and the gauge is ok, and the fan(s) are ok, then you have a problem with flow. Either the block is gunked up or, more likely, the radiator tubes are plugged.

Did you have your radiator rodded? Might be the right thing to do. (The top tank is removed, rods are run through each tube, and the unit re***embled.

Nowadays radiator shops typically only want to replace the unit (highest margin) or 'boil' it out (low labor so good margin). But the best way is to run a cleaning brush through each tube.

 

Was your radiator NEW when you got it or just new to your car?
A radiator for a hotrod should always be checked by a radiator shop before installation in the car.