68 small block and I want to run cooler (wanting to run 180-190 instead of 205-215 and currently have a big block radiator, shroud, fan, alum hi flow water pump, alum heads, ceramic headers, and 180 stat) and was looking into getting a alum radiator. Do they significantly cool compared to regular radiators? Why would I want to use one for small blocks when the big block radiators will fit on a 68 except for the shroud at the same price? When they have ones for 400 horse and 600 horse, it you have 350 horse why wouldnt you want the 600 horse radiator if its only 50 bucks more?

Thanks

You can not have too much radiator capacity (the thermostat will adjust to cold water). That being said you can most definitely not have enough radiator capacity and not even be aware of it. When the Camaro was on the drawing board no one envisioned traffic jams, bumper to bumper, riding the brake at 10 miles an hour, for over an hour in rush hour traffic. Rush hour hadn't been invented yet.

Your radiator was adequate to cool your car at a steady 40 miles an hour (the envisioned cruising speed for which the car was designed). Just like modern driving conditions test antiquated brake designs on first generation Camaros, the cooling system is also being taxed to the max due to it's small core area.

I run two 1.25" flues in a 31" x19" core aluminum core radiator. The stock Camaro's core is 26.5" x17" running two, three, or four, 1/2" thick copper tube flues. My radiator has more surface area presented to frontal air flow, as well as more surface volume than a stock Harrison copper/brass radiator to shed the heat of my engine (582 BBC). I have no qualms what so ever about cutting an opening big enough to allow adequate air flow. The only limiting factor is the overall height available from the bottom of the core support to the top.

Rolls Royce motor cars and all big diesel trucks use well over sized capacity radiators, and then use air slats (those cool chrome louvers in the front of the Rolls grill) to control the amount of air that gets to the radiator and a thermostat to keep the block at optimum temp for proper lubrication. A Camaro wont need the louvers but it does need a bigger radiator core.

That’s my opinion and I'm stuck with it.


Larger Dave

26 1/2"??? What year camaro has that?
Far as I know, all 69's small block, and all 67-68 SB w/o a/c have a 21" core
67-68 SB w a/c & all BB's had 23"

For what it's worth, the opening in the shroud is 23" wide.

That said, Dave is right, more is always better, depending on how much you want to spend.

My 383 ran mostly at 195 (180 thermostat) but would get as hot as 210 running 80 plus on a warm chicago spring day (mighta been 75 degrees)

I put in a summit / northern 21" alluminum (299 out the door) and now it runs at 175, period end of discussion.