so, i am putting a 400hp small block in my 62. its getting pretty close to being ready to drive. i was wondering how adequately my stock six cyln. radiator could cool this thing. Im not looking to run it long term in there. Just to get her on the road and break in the engine. Will it work?

I don't think it will cut it. I'm running a 21" 3 core stock style radiator in my Camaro with a stock fan and shroud set-up with no problems in my Camaro... the stock 2 core 6 cylinder one wasn't enough.

a friend of mine has a 383 in his '67 with a sixer radiator and is doing OK... just keep a real good eye on it. if it works for the time being i guess you'll be OK. i hear tell he runs a tad on the warm side during peak summer months but otherwise he does OK.

i had a 3 row factory style V8 radiator in my '65 and it cost me close to $300.00 for it, in my '64 i have a Summit "universal" 380325 2 row (1" tubes) aluminum rad and it was under $175.00. i have a 400 based engine with a Derale 16217 fan & custom shroud and have no cooling issues.


hope i helped,


JR

You did indeed. I just wanted to know if it would work short term.

short term yes like just breaking in the motor but keep a close eye on the temp if you are going to put some miles on it make sure you use a fan shroud you could always leave the hood off too so it gets alot of the under hood temp down too.

You have doubled the size of he motor. You need to double the size of your existing radiator to install a BBC radiator (two inch wider core than a SBC radiator) with four cores if using brass or two 1-1/8 th inch cores if using aluminum. Otherwise you will have cooling issues could leave to detonation and engine damage.

Big Dave

I would not trust it on the street at all. Does not have the capacity to disipate heat fast enough.

I don't see a big problem until you start making a lot of power, which most guys don't do for an extended period of time. If you set the power output to 400 hp and hold it there, your butt will pucker long before it boils over. I used the stock radiator from a 2-bbl 283 wagon with my 406 and it never had any overheating problems, even while towing.
How much more heat at cruising rpm will the SBC generate than the old engine? Let's assume that they are both about 30% efficient and that it takes 40 hp to cruise down the road.

Radiators are rated by BTU's (some convert BTU's to Horsepower). Your old six was designed to be cooled by the cheapest part that GM thought they could get by with to cool a 120 horse fire breathing six. If you install a SBC 400 (which is the identical size of a 396-402) then you will need the exact minimal, undersized, cheapest radiator that will cool it; or a BBC Nova SS radiator. Anything less than that is asking for cooling problems. To quote Scotty, "You Can'na Break the Laws of Physics!", and trying to bend them leads to detonation and overheating.

Big Dave