The Stovebolt Site Forums The Shop Area The HiPo Shop 37 Chevy w/350 overheating issues

I have a 350 installed in my 37 p/u. Truck overheats after about 10-15 minutes of run time. 180 degrees climbing to over 200, regardless of outside temp. I have adjusted timing, replaced radiator cap. Fan is close to the radiator, but no shroud. I have checked all hoses, thermostat, etc. My question, add an electric pusher fan, shroud or replace the radiator?

depends on how 'close to the rad' the fan is, needs to be 1/2-3/4" and fairly well centered on the rad - but a 350 can easily run 210 with no problems .... also, if you have the stock 37 rad, it will use a 0-pressure cap, which isn't good enough for a SBC, which will run hotter [with more pressure] than the rad can stand

a shroud might help if the fan is more than an inch back, but you really need a pressure cap [at least 7#], which will require changing the fill neck on the rad, and an original rad might not take the necessary pressure long

Bill

You would be better off to install a fan shroud as that will help, also I read in one of the forums(I cannot remember where it was) there. Was a page that told a person how to measure air flow through a radiator and gave sizes you would need to keep your engine cool. Pat

Thanks, I did change the cap and I installed an overflow tank (about the size of a tallboy beer can) and it fills up completely and boils out. Larger can??

Fan is close to the radiator, within an inch or so and centered.

does 'changed the cap' mean a pressure cap, with the proper neck?
I don't think a stock 350 should over pressure a 7# cap, but they do usually use higher, like 14#, which I doubt a stock rad would stand ... but yes, I'd say a beer can size overflow is pretty small, something like a quart can or larger would be better

Bill

Got the radiator and grill removed from the truck. The radiator is a Harrison 46F. Upon draining I noticed some build up of sediment and junk in the radiator, like little rocks. Clearly the radiator has been in the truck for some time.

Rebuild it or replace it? After searching the forum it seems a lot of recommendations for Griffin and Walker. I also noticed a few guys on the rod forums using PCH products.

Just trying to figure out the best way to go. I would hate to put in a "replacement" only to have the same issue.

I have seen no one rebuilding or recommending.

BTW, the 350 is stock.

I'd start with taking it to a good rad shop and have it flushed and checked, for both flow and pressure - then flush the block as well and see how it acts, could be it's just got too much build up of junk .... the old rads are capable of cooling a SBC if they're in good shape

Bill

Just a thought....You don't mention if you have a serpentine or conventional fan belt setup. Are you sure the water pump is the correct rotation for your belt setup ?

Guys, thanks for the responses. I at least have a game plan. Much appreciated.