Race Engine Building - Speed Parts Upgrade

There is little point in having light pistons if the rods they are paired with weigh a ton. But like pistons, the lesser the weight of a rod, the more it seems to cost. Over about 10 years, Scat has done very well with its basic stock weight 4340 forged budget rod. I have used these "no frills" rods in engines making way more horsepower than they should have, and that can be a worry. If a rod fails, the result is almost always a major catastrophe. But the next price-break rod's price was a little over double the cost of these cheapies. To bridge the gap, Scat has introduced an intermediate-priced rod that can take a real beating. Thoughtful design has kept weight to an absolute minimum (604 grams). I have not tried to fail any by running them at progressively higher outputs and rpm, but I would confidently expect them to run in 550hp circle track engines for a long time.

If your budget stretches a little more, Scat has introduced a lightweight version of its regular race rod. Bear in mind that of the many Carrillo-style race rods available, the existing Scat rod, at 640 grams, is among the lighter ones. The new Q-Lite rod weighs 570 grams. When paired with a light piston, either of these rods can contribute to saving a significant amount of weight on the crank's counterweights. The amount saved depends on how savvy your crank-balancing guy is. If on the ball, it could be as much as 10 times the weight saved by all eight rods and pistons combined.

Something along the lines of a big stir at the 2006 PRI Trade Show in Orlando was the wet-flow technology brought to bear on Dart's new Platinum range of Pro 1 and Iron Eagle heads. I got the lowdown on these heads before PRI and was able to get the guys at T&L Engines, just outside of Charlotte, North Carolina, to run some tests on one of my dyno mules.

The upgrades that Dart made apply to both the aluminum Pro 1 and the Iron Eagle the company produces. Some classes call for an out-of-the-box, unported head. Those of you who have used either Pro 1 or Iron Eagle heads know they are competitive. Most of you are familiar with the often-used description of an engine as a "simple air pump." Certainly, everyone who has described an engine in such a way has never had to scratch-design induction systems or cylinder heads. The reality is that it is anything but simple. There is far more to a cylinder head than its ability to flow air. The intake port and combustion chamber must handle the flow of wet, fuel-laden air such that combustion can be easily and consistently initiated to produce an effective charge. You could say that just about every small-block Chevy head available today has some wet-flow technology applied to it by slow, progressive shape refinement based on years of dyno testing and/or the study of fuel stains and chamber burn patterns. But the wet-flow bench is a big step past these basic development techniques, and Dart has jumped in feet-first with a new, high-tech wet bench. The result is the new Platinum versions of the Iron Eagle and Pro 1.

So, how much difference can a successful wet-flow exercise deliver in terms of increased output, especially on heads where the dry flow is virtually unchanged? On the T&L dyno, my mule put out a peak of 482 hp on the baseline test with the original Iron Eagle/Pro 1 design heads. This jumped to a peak of 503 hp with the new Platinum heads. As for peak torque, this went up from 485 lb-ft to 500. The new heads were better everywhere compared to the old heads and hung on better after peak power, where they showed gains of some 26 hp. If you want a quick and easy 20-or-more hp advantage, just check out these heads from Dart.