I agree. I bet the fuel is boiling after a few minutes with only a box fan to cool the radiator. How close is your fuel line to the lower radiator hose & the intake runners? My Hemi did the same thing as the Shaker kept the heat right where it shouldn't be.. & the fuel lines got too hot to touch. Krppy ethanol laced fuel here is a problem. Factory vapor separator w/ return line solved the problem. On my 71 Power Wagon's 383 mag, I ran the fuel line & filter too close to the bottom radiator hose & the heater hoses as well on the top of the block. Vapor lock left me stranded twice. Re-routed the lines & shielded the filter. Huge difference in temp. The heat shield blew off the filter & the temp rose seconds later. Maybe heat is boiling your fuel after 10 minutes. Are you running a return line?
