smallblock intake shootout

duster 340,

The down side of extensive tests like the Mopar Muscle intake dyno tests are time, money and availability/popularity of some intakes. Somebody has to pay for it and magazines have deadlines to meet. It's not an easy job.

As for the Holley Strip Dominator, the test engine was was not exactly "mild" and was more modified than what I run. As an example, I have 360 with unported 587 heads, 1.88"/1.60" valves and a .474" lift hydraulic cam! I also have flattops with around 10-1 compression but this is all in a car that weighs 3,540lbs +! I tried the Weiand Stealth after running the Holley for several years because I wanted to see if that dual plane would help because of all the weight and limited mods. As it turned out, after tuning on the carb for both as best as I could, the Holley was just a little bit better than the Weiand for my application. I shift around 66-67 and go through at about the same rpm. But what may have helped the single plane was that I have a cam with lots of duration, 2.71 low gear, 4.86 gears with 30" tall tires and a converter that "flashes" over 5,000 rpm! My theory is that because my engine doesn't operate below 5,000 rpm for very long, the benefits of the lower operating range and torque of the dual plane is basically skipped over.

If someone has less gear ratio, converter, weight, etc., than a dual plane would probably be better, especially after fine-tuning. Same would apply to the test engine. The time an engine will spend in a specific rpm range will help determine which intake with the respective low to mid rpm numbers posted will work better. Not the peak numbers. That why I said that there are more things to consider, not just the jet changes, squirters, etc. Single plane intakes tend to have a bigger plenum so the vacuum signal to the carb may not be as strong. Tune carb to compensate. Just like a dual plane can have a slight difference from side-to-side because of the plenum depth and volume from side to side. Although some newer designs may incorporate changes to help equal the sides out. I don't know, I'm not an engineer.

As the article showed, it's hard to go wrong with a well designed dual plane intake. It's always safer to lean on the conservative side. But it would have been interesting to see how the dyno numbers would be with more fine tuning as well as track numbers if the engine was put in a car. But, again, it all takes a lot of time and money. So you have to learn as much as you can and fill in the blanks for your combo. "Think outside the box!"