i'll be looking for a new radiator pretty soon (2nd one in 6 years.) and i was thinking about the aluminum one. i understand they keep your engine cooler but will they last a lot longer? from just erosion turning green that kind of stuff. since they keep things cooler what about when it gets really cold in winter? it gets below zero here quite a bit, its not going to freeze up on me would it? and one more thing my engine is just stock 4.0L would it be worth it? any advice would be great.
thanks tom

Sorry Tom The aluminum radiator WILL NOT keep the engine cooler! The engine temp is controlled by the thermostat.. Period! I would be very unhappy if all I could get for a replacement is an aluminum radiator. All I have ever seen have plastic tops and bottoms with a rubber gasket to hold the plastic to the aluminum... Get one like the factory put in there and install a new 195 thermostat and you will feel great joy. <img src="/forums/images/graemlins/smile.gif" alt="" />
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

ok i understand the thermastat controls the temp. but i still dont understand. aluminum disperses heat better correct? so why wouldnt the radiator cool better, wouldnt it take longer to heat up and cool down faster? it claims to give you a 20% cooler system, so why wouldnt it be better? they make engine blocks out aluminum because of there abilty to cool faster, right? these are just random question i have, just trying to get it straight.

Really can't say much about the alum. radiator, but it's the water that does the cooling. Water is an amazing heat sink. Just try soldering pipe that has a couple drops in it. It just can't be done till the water is gone. I don't believe it makes a dern bit of difference what the radiator is made out of as long as it's metal - as far as cooling is concerned anyway. If the aluminum one has plastic tops and bottoms (presumably b/c it can't be soldered, therefore can't be repaired either) I'd listen to BJ and stay far away. Just my .02

Also, I thought aluminum blocks are for weight, not heat. But I've been wrong plenty times.

well yeah the water and antifreeze actually cool the engine but the radiator will help with cooling the liquid. but i'm also looking at the durability of the aluminum. would it last longer than a couple years. but then i didnt know they were made with plastic too. which thats not good, like you said would be tough to repair.

as for the engine block i though it was for both reasons cooler and lighter.

Really I'd expect a lot more than a couple years out of any radiator. Most of mine have lasted 8 yrs. +/- with an occacional flush and the right coolant mix before a recore was needed. And not having a foreign object get rammed through them. <img src="/forums/images/graemlins/ignore.gif" alt="" />

i replaced it two years ago. i think all the salt they use to melt the ice in the winter really eats them up. cause mine is really, i mean really green looking right now, along with the rust...

Man, that bites. I don't know that aluminum would do much better though if it's the salt eating the rad. Might want to do a bit of research on that. Aluminum will pitt pretty fast in a corrosive environment. If I remember my chemistry right aluminum is higer up on the periodic table so it should corrode even faster than copper. I also belive copper is a superior conductor for heat - don't know what the alum. rad. advertisers are saying though. It might come down to the gage of the tubing being used and if they put a good anodic coating on the alum. for protection.

The cooling of the engine depends on heat transfer at the radiator. I believe you're right about aluminum transfering heat better than brass, I doubt that it is more durable. You won't see it in air conditioning units made for salty environs. But brass and copper do a darn good job of heat transfer too. The last two or three failed radiators I've seen were aluminum and plastic. I would never buy one to put in a Jeep unless it was the only option. If you need more cooling get another core. (3 or 4) <img src="/forums/images/graemlins/cheers.gif" alt="" />

Aluminum radiators are lighter. They can cool better, but so could a brass/bronze. It really depends on flow rate, and surface area. Since the metal is relatively thin, the heat transfer capabilities are all fairly close. A stock radiator will cool a stock motor just fine.... They are built for that...

I take my above stock motor, go offroading in the mountains in 90+ degree whether WITHOUT a fan shroud pulling 3K RPM's in 1st gear low-range up steep hills and don't manage to over heat my jeep...