Discussion in 'The Garage' started by Big GMC truck, Aug 23, 2005.
Should you break in an engine with water or coolant?
Use water. If anything goes wrong, it's fine to dump on the ground, easy to refill, and cheap.
Besides, water is a better coolant than antifreeze.
no its not better. anti frezze helps transmit heat from metel to water better. and keeps the boiling point much higher also along with a good cap.
edit: i guss i was wrong on my therory.
I use water during the first 30 minutes in the driveway, put the hose in the radiator, turn it on a little and open the drain.
Water has a higher heat rejection rate than antifreeze. I use water because if you have any hang ups,you can just dump it on the ground. Get everything checked out then refill with distilled water and antifreeze. Antifreeze has a higher boiling point than straight water. Water is more a efficiant coolant.
I wish i'd thought of that. Good Idea!
Check the properties of glycol and water, you'll see that water absorbs heat more readily than glycol, which means it's a better coolant in that regard alone.
Then check out the antifreeze manufacturers web sites, and look at their charts of "boilover" protection. You'll notice that most (all I've seen) have in the fine print "tested at 15PSI". Then find the boiling point of water at 15PSI, and you'll see that antifreeze does NOT add as much temp to the boiling point of water as pressure alone does. (figure out boiling point of water at 15PSI, then subtract that from the manufacturers data, it's something like 15* IIRC) They'd like you to believe that, which is why they show data collected at 15PSI.
I've done all this research, I know why they call it "antifreeze". That's all it's good for, along with being a corrosion inhibitor and any lubricants/conditioners that are in it for seals.
there's your answer right there, being 100% safe to dump out on the ground, and free is an added bonus.
Water is free huh? I'll send you my next water bill.
I use water for engine run in and checking out problems . In Utah you couldn't get thruogh the winter with out anti frezze. I used to work on locomotives, mostly 2 stroke EMDs . Short of having a shop to put the locomotives in, they are run without anti freeze. With exceptions like having them in very cold climates, like wyoming, montana. In the older EMDs engines the ''a' and b'' series,used a lower and upper ''o ring'' to seal the liner in the air box and crankcase. If the seals failed you had antifreeze in the air box or crankcase.Then the problems begin, it would build up in the air box until the locomotive stopped or accelerated , then it would suck the coolant into the liner. Usually puting a hole in the top of the piston, bending a con rod or worse. Antifreeze if heated enough will burn hotter than hell. Usually ruining any componants in the area. If it got into the crankcase,well have you ever noticed how sticky antifreeze is ? It would get on the main and rod bearings and grab the bearings to the point of spinning the bearings.
If it was a small leak into the crankcase, it would imulsify with the oil and create a jello from hell in the oil cooler. Then when it gets cold enough to freeze the antifreeze it gets even more fun. Try 55below 0 and you have to get a torch to melt anti freeze out of barrels. Yes anti freeze does work , but its a pain.
you avatar changing bastard.....
anything mixed with water raises the boiling point...anything...at 15 psi the best you could hope for would be 227 (before boiling over)...less at higher altitudes...so a 50/50 mix raises the boiling point even higher. i think 45 eth.glycol/55water yields a slightly higher boiling point, which is why gm recommends it in warmer temps...
I presume you're running the engine 'in' after a rebuild? The use of water alone for this purpose has merit with the 'dump-on-ground' scenario and then after running-in I would drain and fill with anti-freeze which is also a corrosion-inhibitor. This will help preserve the insides of your cooling system even in warm climate.
I've always understood the glycol was also helpful as a 'wetting agent' which improved the water-to-radiator contact and improved the heat transfer away from the engine.
Glycol also used to be used as an 'improver' in wine but this was outlawed 15-20 years ago i think.
who me or not?
Where are you getting your figures for boiling points under pressure?
Under 10 PSI pressure the constants are: 239.4° F saturation point...
This shows 15PSI being needed to keep water from boiling at 240+*
Explain the boiling point of 221* in the "unpressurized" physical/chem characteristics chart, but the huge temperature leap under pressure. At best it's +16* with a 50/50 mix at 14PSI, the remaining 28* coming from?
its not the "stickiness" of the antifreeze, its when it gets picked up in the oil pump and distributed to the bearings. the bearings quickly vaporize the coolant, and the bearing goes metal to metal with the crank. the bearing actually welds itself to the crank and spins. nothing to do with the coolant being sticky.
Yes and no, bearing crush is a mix of a interferance fit, and a mechanical locating device, usually a tang. A engine will run a long time with little or poor lubrication for a long time. We have all seen the snake oil tv adds, where an engine with no oil is sprayed by a fire hose in the rocker area.With no load that engine will run for quite a while.Granted at rated horsepower an engine with poor lubrication will friction weld some part of the rotating assembly. How ever an engine at low to moderate load, can have a differant scenerio. The differance in coefficant of friction between lubricating oil and antifreeze is rather large. One that is enough to ''spin a bearing '' , and have it turn into a fullfloating bearing.That can be done with antifreeze. I guess this is the same point, antifreeze in the crankcase is bad.Good point though, after turning wrenches for too long , just when you think you have seen it all. Just go to work the next day, it will just get better.
I take it that you have not seen a rod bearing that will turn in the rod bore, and on the crank at the same time. If its not retained to prevent rotational movement in one of the bores, the bearing is floating . Is it not?
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