Edelbrock's Pony Ram
It is very rare when you find a piece of equipment that offers you a performance gain without sacrificing gas mileage or hurting performance in a certain rpm range. The only way you can perform this kind of magic is by increasing the overall efficiency of the engine. This is just what Edelbrock has done. Edelbrock engineers have come up with a manifold for the 2000cc Ford Pinto engine which greatly increases performance throughout the engine's working range while having no adverse effect on gas consumption.
The design of the Pony Ram started with an examination of the basic flow characteristics of the stock cylinder head, keeping in mind the valve event (lift and duration) of the stock or street/strip-type camshaft. For stock parts the factory head and manifold are basically well-designed units, perhaps due to their German-engineered heritage. Too bad the same thing can't be said of the domestic designed engines of similar size.
Quantitatively, the head does not flow a lot of air, and the stock manifold has some subtle features in it to minimize restrictions. A small change in the flow volume, either plus or minus, has a much greater effect percentagewise in these small engines than it would in a larger V-8 type engine. The stock two-barrel carb also has some unique engineering features. The butterflies do not open simultaneously as they do on most carbs of this type. Instead the Pinto unit is more like one-half of a four-barrel, with a primary and secondary throat. A staged throttle linkage allows for a progressive opening.
The head, manifold and carburetor(s) must be a compatible unit to achieve a performance increase throughout the operating rpm range. Edelbrock engineers increased the flow characteristics of the unit by designing a manifold with high air stream speeds. This high stream speed principle increases an engine's torque capabilities, especially at low and mid-range engine speeds. Visually, this was accomplished by making two pairs of fairly long runners and connecting them with a small volume plenum. In fact, many of the concepts that go into an I.R. (Individual Runner) manifold were incorporated in the design of the Pony Ram. Each pair of runners is fed by a Holly single-barrel carburetor, part number R-6467, rated at 185 cfm each. These carburetors have been specially calibrated by Holley to be used in conjunction with the Pony Ram manifold. The cost of these carburetors will be comparable to that of a single four-barrel.
The manifold, as sold by Edelbrock dealers, come complete with a linkage kit and all the necessary fittings and hoses to hook up the emissions system. Initial tests have shown that the new manifold has better idle emission characteristics than does its stock counterpart.
Performance is where the Pony ram really gets it all together. Acceleration times from 0-60, 20-60, 30-60 and 40-60 showed up to a one-second improvement over the stock factory setup. On both setups the engine had been tuned to insure accurate performance data. Week-long mileage checks showed that the Pony Ram did not effect the economy of the vehicle in any measure-able way. The biggest difference is the way the car feels when driving it. You might say that the Pony Ram has made the Pinto a real quarter horse.