I usually use 100% antifreeze in my radiator. I was reading a motorcycle book today and the author wrote that using any micture greater than 60-40 can cause an increase in the freezing temperature and a decrease in heat removal properties. I've always heard that using 100% isn't any more beneficial than 60-40 but that it is not harmful. Any thoughts?
Kevin

 

i don't have a book or a jug of antifreeze to look at but i've always heard 50/50 or 60/40 mix is the ideal for cooling and heat removal and that straight anti freeze is very much protection for your engine.

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ICON Motorsports
1st & 3rd

 

I know Prestone recommends a 70-antifreeze/30 water maximum. I've also heard that straight antifreeze will freeze at a higher temperature.

 

Straight 100% antifreeze will gel in cold temperatures. It should be mixed at no less than 50/50. 60/40 is prefered.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

Count another vote for 60/40! I always go by that!

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Working on:
'84 Z28 LG4 305
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is in shop!

Awaiting results from all 8 ASE tests.

Starting to look like the Kicker poster child!

 

I have a question kind of like his

Is any one antifreeze better than another when it comes to electrolisis? What is the best way to keep our aluminum heads and manifolds from being EATEN ALIVE?

 

Antifreeze is good, you need antifreeze... trust me I know this now.

 

As far as heat removal, straight antifreeze is worse than a mix, or straight water. The reason you need it as "coolant" is to keep the water from boiling. The other option is a higher pressure cooling system. You'll notice most race cars (ie NASCAR) don't run any coolant, they run a higher pressure cooling system which keeps the water from boiling.

 

Yes, increasing pressure also increases the boiling point of a liquid. Antifreeze also does this to a point, but it's on a curve so once you exceed 60/40 a/w or maybe 70/30 the boiling point starts to come back down. I think the freezing point also starts coming up. That might not be exactly what happens, but regardless 50/50 or 60/40 are your best bets.

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89 Iroc-Z LB9 305 TPI auto 2.73 posi:
3" Dynomax "cat" back,K&N filters, TB bypass, 3" pipe in place of cat, cleaned and flow-matched injectors, 180' thermo, mild ignition mods, synthetic oil, kicker sound system, soon to attempt engine swap...

 

Personally, i try to run no stronger than 50/50 antifreeze, ever. Antifreeze has completely *** heat transfer properties, and in too strong of a mix it does a bad job at cooling.
True story. The 83 grand prix i was driving was having some overheating problems when under load in the hot months. I recalled that when i had done the radiator hoses i had refilled the radiator with straight antifreeze. I don't know what my exact mix was, it wasn't pure, but it was better than 50/50 i'm sure. Anyhow, on a educated guess, i drained the radiator and filled it with straight water. Guess what, it never ran hot again.
And as for you people worried about freezing your engine. I used to run only a ~25% mix in my old camaro, and it survived weeks of single digit temps and below in state college PA. Hairlily close to freezing, yes, but i have a thing about hot running cars..
...ed

 

The purpose of the water is to cool the engine, the purpose of the coolant (anti-freeze) is to keep the water from freezing AND protect the iron block/heads from rusting and corrosion due to the water. I've heard anything less than 50/50 will allow the block/heads to start to rust.

Hope I've heard right and this helps,

Jason

 

Valid point about the anti-corrosion properties of anti-freeze, however, i'd much rather have a super efficient cooling system and need to do a flush every so often than have ****ty cooling. There are even some fringe theories that you can get better engine performance by running little/no AF because the water will pull heat a lot more effectively from the small pockets in the heads, whereas strong AF mixtures tend to insulate these pockets. And these localized hot spot inevitably lead to detontaion problems. Fringe, but kinda makes sense.
...ed

duh, forgot to mention that additives such as water-wetter contain anti-corrosion packages as well as make water pull heat even more effectively from the engine. Fairly cheap and good extra insurance against rust and overheating, especially in the summer.

[This message has been edited by Ed Maher (edited December 29, 2000).]

 

I have to agree with Ed on this one... I can recall several cars I've owned in the past that ran better with 40/60 than they did with 60/40. A cooler car in the summer, and never had any problems here during Chicago's winters. If you decide to do this, just make sure you flush your system more often than usual. Of course, this is good advice for just about everyone. - John '89 L98