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Questions and Answers - What's Your Problem?

Jeff Smith Answers Some Of Our Readers' Questions

Assuming the compression is adequate, we'd stay conservative with a flat-tappet hydraulic camshaft of less than 220 degrees of duration at 0.050-inch tappet lift. Edelbrock offers a Performer-Plus camshaft that is designed to work with its Performer dual-plane intake manifold, and this may be a great place to start with your street engine. This is oddly a single-pattern cam, meaning the duration and lift are the same for both the intake and exhaust lobes at 204/204 degrees at 0.050 with 0.420 inch lift for both valves. This is based on a 1.5:1 rocker ratio. This cam is designed to work with the Edelbrock Performer 318/360 dual-plane intake manifold (PN 2176). As for a carburetor, any 600-cfm carb, such as a Holley, Road Demon, or Edelbrock Performer series will work just fine. You don't need a big 750-cfm carb because the engine does not need that much airflow.

This would make a great combination, assuming you have a set of 151/48-inch headers and a free-flowing exhaust system with 211/42-inch pipes all the way out the back. Even on a small-displacement engine like the 318, mufflers are an important component. Any of the well-known brands such as Flowmaster or DynoMax can keep the backpressure low, which is key.

For the transmission side of things, stall speed is the amount of slippage in the torque converter. The easiest way to check this is to mash the brake pedal as hard as you can and then, watching the tach, see what rpm the engine goes to without the tires spinning. A stock converter will be around 1,800 rpm; for your application, we'd stick with the stock converter for now. A higher stall speed allows the engine to launch closer to its peak torque rpm, which is the equivalent of launching a manual trans car at a higher engine speed. The negative side to a higher stall speed converter is that in everyday driving it also slips more, which reduces fuel mileage, and that may be a concern with prices well over $3 a gallon. As for a gear ratio, your 318 would like a little more gear than a larger motor since it makes less torque, so a 3.30 to 3.50 rear gearset would be a good compromise between highway rpm and good acceleration. Have fun!

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