Hey Moparts Techs, I need some professional assistance with a cooling issue I am having.

I built a 408 stroker 2 years ago for my 74 Scamp that I drag race and I have been having a difficult time with it heating up faster than it did with my 340 and it also takes longer to cool it down. The machine work was done by Kammer's. They hot tanked the block after doing all the machining. But im pretty sure the issue is that the block has been filled with Hard Block which pretty much takes away about a 3rd of the water capacity in the block. I run straight water with coolant additive that is supposed to help keep the water 30 degrees cooler than just plain water. I run a stock style pump but with a Moroso belt drive pump. The belt drive has a underdrive pulley on the motor. I also run a 3 year old Afco 2 core aluminum radiator. I switched electric fans this past winter from a 1700 cfm to a 2600 cfm thinking that would help but I haven't seen much improvement. I do not run a thermostat. The fan and water pump drive are on separate switches but really never run them separate. I leave the line at 160 degrees because that is where it like to run the best.

My real question is, do I need to slow the water down with a restrictor so that the water stays in the radiator longer, or do I need to pump the water fast with a high volume pump so that the hot water gets out of the engine faster?

any advise would be greatly appreciated!

thanks
BP

I had problem with my aluminum headed pump gas (no fill) 340 overheating with a new copper radiator and a flex a lite black magic fan. Tried a Flowkooler pump and a high flow thermostat, still hot. So I bought a new 22" aluminum radiator, a 2800 cfm big amp draw electric fan, still hot. I thought there was a problem in the engine and was going to tear it down. Several people had recommended a viscous fan and shroud. As a last ditch effort I bought and installed one and fabed a shroud out of a factory one for a 26" radiator. No more heating issues, I have this set up on my 408 and it seldom gets over 175 with a 160 stat.

Just a quick update to this, my buddy is a fabricator and is going to fab am aluminum shroud for me, so hopefully that will take care of the problem...HOPEFULLY!...:)