psig, we built it to have around 450-500hp i get the cooling as much as u put out and i dont plan on standing on it for more then a min,just want to make sure we have no problems when we sit in traffic at the rod-run's for hours,, and long trips from home on the hwy at 65-70mph,,so do u think the stock radiator will keep it cool then?
Mine do. Standing on it a minute is the only time that an oversize radiator is beneficial. My 427W runs a 160° performance thermostat and a true clutch 7-blade fan with shroud, which gives it 175-180° running temps and never goes beyond unless I blast it through the gears - then it will spike to high 180s to low 190s due to the small radiator area and limited coolant mass. Any stock or modified car that is just idling should behave like any good stock setup, and idle all day long at good temp. In traffic, parades, and cruising home should all be easily handled by a stock-level system. What you see with
most issues is poor airflow, poor heat transfer to or from the coolant, or excessive heat production (usually related to ignition timing). Often it's a combination.
I have a 61 Z code 3 core radiator, recored, and my stock rebuilt 2 bbl 352 still overheats in the summer. I added an eBay electric pusher fan I switch on when the temp starts rising and you can see the temps drop down. I have a 5 blade fan but no shroud, that should be my next addition.
Mike
Mike, your issue sounds like it's mostly airflow, given your system does cool more when you use the pusher fan. I assume this is at low vehicle speeds. That indicates your radiator is good enough and it needs air. I agree a shroud should be your next improvement. When doing shroud setup, try to get the fan blades about half-way into the shroud ring, leaving about 1/3 to 1/2 of the blades exposed out the back. The fan blades seem to run most efficiently at about this point, and function as a ducted fan. Also note that when set up this way, the fan's distance to the radiator becomes unimportant. Shrouds make a huge difference in airflow
through the radiator where the airflow does some good. You might want to check to see if your vacuum advance is also functioning correctly. I can take a perfectly good system, retard the timing just a few degrees, and overheat in minutes.
In all these cases, you have to look for the real reasons for issues, as these cars had no cooling issues when new with their standard radiators, and you shouldn't either. Good luck!
David