Aluminum rad?

[85_prairieboy]

I have been having overheating problems with my truck. It only overheats on warm days when idling but nothing is worse than being stuck in traffic and watching the temperature climb. Popping it into neutral and revving it up helps somewhat but I know I have to do something different. The engine is a 10.5:1 350 with AFR 195 Eliminator heads and an aggressive cam making 425-450 hp. The last time I built my engine I used a Weiand high flow water pump and installed a Flexalite electric dual fan setup on the rad. There was a small improvement. The rad is still the factory small core rad but I initially thought the dual fans should be able to keep up with the heat compared to the old belt driven flex fan. My question is what rad do you guys prefer? Should I spend the big bucks on a nice aluminum rad or find an oem rad that would have cooled a big block? Or am I overlooking something?

[Walts_restoration]

4 core copper would be my choice, can have one pretty cheap (at least in my oppinion)

If you go aluminum, dont get plastic tanks in my opinion. Something about my 91 camaro giving a smokescreen for everyone downtown...and it wasn't my tires lol. They get old, get cracked, and ya....

[James McClure]

I've been running one of those new style alum rad's for a few years now w\plastic tanks without an issue. Heat is the problem with plastic and most of our vehicles run 195 degree thermostats stock. I dropped mine to 180. I pull a 7000# trailer and have never had any problems no matter how hot it was outside. jim

[swb85]

I'm running a cheapy replacement 2 row (1" tubes) aluminum rad w/plastic tanks, high flow pump, high flow 180* stat and single 16" electric fan. Temps stay at 180-185 even with the a/c on high in 105+ ambient temps.

[Pyrotechnic]

I'm running a brass/copper 4 core big block radiator with dual LS1 fans. Cools great.

How old is that radiator ? There's a good chance some of the passages could be clogged and hindering it's performance if it's old or if the cooling system was neglected in the past by previous owners.

It seems like these days if you go to the parts store for a new radiator, it's going to be the aluminum/plastic design unless they had an older copper/brass sitting in the back.

[87c10slammer]

i have ordered 2 off this guy.. one for my 00 jimmy and the other for a 91 sonoma sbc swap... both came in great shape.. no messed up fins or anything.. his ebay store is... http://stores.ebay.com/radiatorclassic ... came in less then a week..

[85_prairieboy]

The truck does have an old two core rad in it. According to the VIN the truck originally came with a 4.3 liter V6 and it could be the original rad from that. I am thinking that at idle the rad does not have enough capacity to cool the 350. At highway speed the truck runs at 160 which is what the thermostat is set at.

[piecesparts]

I have a 383 stroker motor with an aluminum "Be-Cool radiator. The dual 11" fans shut down on me one July (when the relay failed and that won't ever happen again) and the engine did not overheat, because the radiator was large enough to cover the heat build up. The fans are a definite trick to the cooling issue, but Be-Cool also will tell you that the flow through the engine is important, too. They state that too fsst of a flow iwll not absorb the heat and cause some problems. They claim that they can figure out anyones problems, if given a chance.

What do you run for a T/stat? Is it a lower setting than what is recommended? Do you know if it is a SUPER-STAT design? That design regulates better than a standard T/stat and holds your temps more stabile.

[slugish]

went back & forth with the same issue with my 400 small block

have an inexpesive Griifin Alum. radiator > trie delectric fans > both in front & behind radiator.

Put flex fan back on , with a homemade shroud & havent had an overhrating problem yet in all kinds of weather & situations .

The shroud ended up being the key.

Thats what worked for me , we all have our stories .

[slugish]

forgot , for what its worth , I RUN A 160 DEGREE thermostat. temp never been over 180degress since. with electric fan would get to 240. was in a parade in july a few years back . Got so hot I CUT ENGINE OFF in the 4th of july parade & with help of otheres pushed my truck the remainder of the parade route. that sucked as well as embarrassing

[85_prairieboy]

Piecesparts
ya I have heard of too much flow not absorbing heat too. Justlike when guys pull out their thermostat for more flow and then wonder why they are overheating worse. I will probably try a larger aluminum rad. The ones 87c10slammer showed me look pretty good. I know my rad is too small and I guess I lost the gamble when I thought just the dual fans would fix the problem.
Slugish
My old flex fan did not fit into the shroud well at all. There was a 5 inch gap on the top and 1.5 inches on the bottom. I thought about building my own tight fitting shroud. Maybe I will end up doing that if I still have the problem with a new rad

[Pyrotechnic]

Seems like 350's got a 3 core copper/brass from the factory which is a decent one. If that was a 4.3 V6 truck and it has a 2 core, then yes, that is undersized for a V8 and is most likely the cause of your problems.

[85_prairieboy]

ya I have a 160 thermostat too. One thing I just remembered was one time I shut my truck off and noticed the temp climbing on the gauge. The gauge is one of those manual capillary tube type. The needle climbed right up to the top. I got scared and checked the pressure on the top rad hose and it wasn't as much as I thought it would be. I know my truck is overheating at idle but could the heat from the headers make it look worse than it really is? There is no heat shield between the sender and the headers

[Pyrotechnic]

A few degree extra from heat soak after you shut the truck off is normal. Mine never gets into the danger zone from just shutting off, but it will climb up around 10-15 degrees at most from heat soak.

[flamingbig10]

I have a afco aluminum 4 core radiator used in dirt track cars, it keeps my bored 30 over sb block cool in 100 degree heat in traffic

[gchemist]

I run a 454 aluminum radiator with LS1 fans. No cooling problems. When the fans kick on about 205 temps drop to 188. Temps drop to 182 if the truck is moving.