getting ready to replace the radiator on my 79. are the aluminum radiators worth the expense??? they're real expensive compared to the others.

 

Copper in radiators and aluminum in cylinder heads or elswhere causes a dissimilar metal concern. If you have an all iron engine, use of a copper radiator is not a problem. Also,in an all iron engine, use of aluminum is not a problem . However an engine, with both aluminum parts and copper parts can cause a problem. If, in the cooling circuit of your engine you have aluminum and copper parts there is a problem with corrosion. The air cabin heater core of your car is copper. If you add an aluminum radiator there is a potential dissimilar metal problem. If you have an aluminum radiator and a copper heater radiator, use at least a 60% ethylene glycol ( antifreeze) and a 40% distilled water mixture. This is what Be-Cool Aluminum Radiators recommends. Actually I use 100% ethylene glycol (antifreeze).

If your cooling circuit has aluminum and copper, you don't want to use tap water - the minerals and chlorine will support an electrical current to flow between the copper and the aluminum. This current will cause errosion with (I think) the aluminum. Use ethylene glycol because it is a dieletric (doesn't allow current flow) and distilled water acts somewhat like a dielectric. Water has, of course, better heat transfer characteristics than ethylene glycol. (Anyhow with my copper/iron/aluminum corvette cooling systems I use only pure ethylene glycol and have had no problem in 20 years.)

 

I have a Dewitts and Spal fans and feel it's one of the best mods I made.

 

GRIFFIN RADIATORS PROFESSIONAL PEOPLE selling A QUALITY PRODUCT.

 

Yes, they work Great! I have a Griffin from DeWitts. Highly recommend them.

 

just bought a $614.00 Griffin off e-bay, little less then 1/2 price

I love e-bay, best part is no sales tax

 

I put a Dewitts 'direct fit' in my 76 with no mods and lowered temps to 180 from 210.

 

I put in a BeCool alum radiator 5 years ago the same time I put in my new modified motor. I wanted to be sure that there would be no cooling issues with the new motor. Since then, DeWitt has now come on board as a supporting vendor.

 

Lost 20 degrees with my Be Cool. My motor makes 500 horse at the flywheel and I drive it every day. So you can imagine the kind of heat that it generates. I run it with a 7 blade clutch fan and it runs exactly at 180. No matter what kind of weather it is.

 

I disagree. I think GM engineers know more about materials and coolants than the whole forum put together, and that includes me. As you pointed out, every heater core made was copper/brass and many of these were used with aluminum radiators and surge tanks without any problem. Every week I replace a surge tank or aluminum radiator that the customer claims is the original 40 year old unit. Now if these radiators lasted that long with poor coolant and maintence, how long would they last if we changed it every two years? And running straight EG is just wrong. It runs hotter and often causes problems in the summer months. The inhibitor package in EG is designed to stop corrosion for 24 months and not one car made ever came with straight coolant. I bet this 50/50 mix was tested a few times too!

 

Mr DeWitt, what do you think about using a STD radiator from say Modine in my driver?should i expect the same performance as the stock radiator had 30 years ago?

Robin

 

Hey !!! Don't forget ...SPAL electric fans. AWESOME COMBINATION

 

The most powerful internal combustion engines ever made and with liquid cooling were the World World II fighter planes and the same planes later adapted for unlimited class racing. These World World II fighter planes, with all aluminum engines and radiators, used 100% ethylene glycol in their cooling systems. You said using "100% EG is just wrong" My resonse is to just repeat ...these aircraft used 100% ethylene gycol in their cooling systems. If there was a better fluid to use in their cooling systems, they would have used it. If I'm wrong I'd welcome having someone tell me. Also, when these same V12 engines were later used in Army tanks, they still used 100% ethylene glycol. I've used 100% ethylene glycol in my Corvettes and daily drivers and have never had any problems. (I wonder if water hose lifetime and water pump seal problems may be aggrevated my 100% ethylene glycol.) I'm curious as to why you would say that useing 100% ethylene gylcol is just wrong.

 

I am guessing DeWitt said that because water is the best medium of heat exchange, period.

 

I guess what I'm saying is is that when you consider everything, water cannot be said to be the "best" without a lot of qualification. I think that if you're talking about de-ionized water (i.e pure distilled water) in a fluid circuit, say of only one metal such as common materials like stainless steel, copper, or aluminum, pure water is an effective heat transfer agent. The problem with water is that it can quickly become chemically active especially when it has contact with impurities. Water, H2O, tends to dissociate into hydrogen atoms (H) and hydroxly molecules (OH), these components are extremely chemically reactive and in the presence of other metals, chemical reactions will occur. Another consequence of water's dissociation into hydrogen atoms and hydroxyl molecures is that it is electically conductive. When water contacts dissimilar metals such as copper an aluminum, an electrical current will flow that will cause corrosion.

Opps.. were we talking about the best conductors of heat? Actually helium gas and liquid/gaseous mercury are other elements that are often used because of their efficient heat transfer characteristics.

Anyhow, my understanding is that ethylene glycol is a very effective heat transfer media. And thise means 100% ethylene glycol ... not a water mixture. It actually has a long history of being used 100%. It actually is not quite as good of a media as water, but it has a lot of advantages. One important advantage is that it does not conduct electric currents which means that it does not present a corrosion hazard.

 

The modine replacement is fine. You started with a very large (27.5") copper brass radiator and modine makes an equivilant four row c/b that will do a good job. Our aluminum (Direct Fit) radiators are for the guy that souped up the engine and is now running on the hotter side or just wants the maximum amount of cooling without changing any thing. The cost for aluminum is going to be about double the cost of a replacement radiator and for some people, that's just not an option. Yet often I see people drop 5-6k into building a monster engine and then squeek when it comes time spend the money to cool it down.

 

That is totally my point. Many Corvette radiators are marginal in size. They will cool the engine only if everything is working correctly, meaning, clean inside, no corrosion, no leaves in front, and in many cases proper mix ratio. As a "full time" radiator supplier, I talk to one individual a week that is running 20-30 hotter than he/she would like and later find out they are using straight anti-freeze. And they thought it was better (cooler) to do so. Most of these times I talk myself out of a sale by suggesting they go back to 50/50 mix and the temps drop to normal.
I try to educate people on cooling as much as I can because there is a lot of myths and misnomer out there. The forums are FULL of..., well these theories and they really can mislead people. If everyone was to follow the suggestion of running straight E/G, then most of them would experience a rise in coolant temperatures. I'm simply trying to show them how to run as cool as possible without buying anything. If in the end they need an aluminum radiator, we'll be happy to sell one.
Water does introduce some harmfull issues but the cooling advantages offset these. The inhibitor packages included in the E/G today will protect all the components in the system as long as you don't push it beyond the normal life. So run 50/50, and change it every two years, or sooner.

 

Tom, Your thoughts on this product?http://www.evanscooling.com/main21.htm

 

In this and other articles you'll read about 100% propylene glycol. Evans is promoting the use of non-aquous propylene glycol as a coolant for high performance automobile engines and also for use in commercial fleet diesel engines. This coolant is 100% propylene glycol - no water at all. I believe that propylene glycol is being promoted as a replacement for ethylene glycol primarily because it has a very high 360 degree boiling point and also because ethylene is very toxic if ingested. One of the problems with water in engine coolant is that engine hot spots will cause say a 50/50 mixture of ethylene glycol and water to boil at the hot spots and thereby decrease cooling effectiveness. I think 50/50 boils at 225 degrees. Evans has some technical documents discussing this - they're interesting reading.

Another benefit of ethylene glycol or propylene glycol -with no water - is that there boiling point is very high. 260 degrees I think for ethylene and 360 degrees for propylene. This means that your engine cooling system will never be pressurized. There's less problem with leaking. The higher boiling points for these glycols is the reason they don't turn to steam at engine hot spots.

Evans states that they are coming out with a new radiator/cooling system for Corvettes.

Incidentally, an very effective antidote for ethylene glycol poisoning is ethyl alcohol aka vodka!!! Ethyl acohol will block out the liver from metabolizing ethylene glycol (EG) and the EG will passed out the body harmlessly.

 

Huh... two Toms? Anyway, Evans is really for hard core racers that don't care the engine temps go up 15 degrees. It will run hotter than a 50/50 mix and it costs a lot.