If you've kept your 20 years of HPP magazines, you'd find one from five or six years ago with a manifold and header dyno test where a new set of Hedman long tube headers added 20 horsepower. But even if you still want those cast-iron manifolds, this combo yields full-time driveability with the ability to run some surprising numbers at the track.
Aluminum Vs. Copper Radiator
I've been reading High Performance Pontiac for more than 20 years and loved every issue. I just have one question and hope someone will answer: What's the difference between an aluminum and copper radiator, which is better, and why? I have a four-core radiator in my '65 and everyone tells me to go to an aluminum one, but can't give me a good reason why.Terry KiserLadson, SC
Ray T. Bohacz Responds:
The difference between an aluminum and a copper/brass radiator is weight. It is misbelieved that an aluminum radiator is more efficient in heat transfer than the older copper/brass designs, but the exact opposite is true. The advantage of aluminum is that it weighs less but needs to be larger in size than a copper/brass unit. This made aluminum radiators very popular in racing, especially for drag cars, since any mass removed from the front of the vehicle would allow for improved weight transfer during the launch, and hopefully better traction.
If your Pontiac is street driven and saving a few pounds is not a concern, a well-designed and high-quality copper/brass radiator will out-cool an aluminum one, while being easier to package since it takes up less room. That is why when you see a performance aluminum radiator it is so large; it needs to be to improve the thermal efficiency.
With the risk of sounding like a sales-man, I wrote a book, Engine Cooling Systems that you might enjoy. It is published by HP Books and can be found in most larger bookstores, and also at Evans Cooling Systems (888) 990-2665. I hope you are now clear on this subject.