Big Block Water Pumps/Radiators

[John M.]

I'm putting together a 67 big block and have purchased a Dewitts Aluminum radiator rather than the OEM copper brass. Will the stock BB water pump, in combo with this radiator keep the temp in range?. For a 69 BB I used a Flowcooler pump and the std. radiator and it worked fine. Is the biggest improvement over stock gained from the pump or the radiator?
Thanks for all advice

[Craig S.]

Re: Big Block Water Pumps/Radiators

John, I assume you are using the aluminum radiator that is used for the L88 cars....which is 2" wider than the small block aluminum radiators. I am also assuming that you are managing to keep the fan shrouding intact to direct air flow through the radiator. Given all of that, you should have excellent cooling of your BB with the aluminum radiator. The radiator itself is more important than trick pumps, more pump flow doesn't mean cooler operation, what is required it proper dwell time of the coolant in the radiator to effectively cool it down before it exits and passes back to the engine. Too fast a flow, and it goes back warmer since it didn't have sufficent exposure to the airflow and cooling effects of the radiator. Personally, I would use a standard GM water pump, with a good cast iron impeller, and you should be in great shape...Craig

[Joe L.]

Re: Big Block Water Pumps/Radiators

John-----

Which radiator did you purchase? The reproduction GM aluminum radiators which DeWitts manufactures or the Griffin aluminum replacement for original big block copper/brass radiators which they sell?

The reproduction GM #3155316 or GM #3007436 aluminum radiators will not work with your 67 big block radiator support or 67 fan shroud.

[John M.]

Re: Big Block Water Pumps/Radiators

Joe, Craig,
Tom Dewitt told me that this radiator will fit the big block support, shroud etc.
If you look at his website I believe it's listed under racing, but I called and gave specific details of what I had and he sent the aluminum radiator to suit.
It looks like it will fit correctly....
I'll use the GM cast iron BB pump that I have. Thank you both for your help.
John

[Joe L.]

Re: Big Block Water Pumps/Radiators

John-----

I just checked out their web-site for the first time in quite awhile. It looks like they have a new line of "direct fit" aluminum radiators. These look terrific to me. The configuration is closer to stock than the Griffin units. Paint one black and "they'll pass". Maybe not for judges, but they'll look stock to just about everyone else. Plus, you get the extra cooling capacity of aluminum. All this and direct bolt-in. What more could you ask for?

[Doug Flaten]

Re: Big Block Water Pumps/Radiators

Within reasonable limits, increase flow rate will increase heat transfer. Example, a 20% increase in flow may yield a 10 to 15% increase in heat transfer. It will also consume more horsepower and thus generate a bit more heat, but it is fairly small when you are talking about the big block horspower. The aluminum radiator will have a bigger effect on the heat transfer. DeWitt's web site shows a test on the same size radiators, and the aluminum was rated almost 30% more than the brass/copper radiator.

[Craig S.]

Re: Big Block Water Pumps/Radiators

Sounds like you can have your cake and eat it too! Tom has great products...Craig