Thread: Older Chevy pickups

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Does anyone have any ideas on building smallblock engines for peaK fuel effiently?My partner and I are trying to build older chevy pickups with six and eight cylinders with a goal of at least 20 mpg's.

There is a student here who built a 28 mpg El Camino with a 468 big block. He used a tall deck 427 from a commercial truck, ported the heads so he would get 2500 feet per minute of flow at cruising RPM (there is also a special shape to the port you must make), then he put a torque cam in, strapped on Accel's fuel injection unit, ran 11:1 compression, and is running a 2.29 rear end or so on a manual transmission. He makes 310 hp at the wheels and makes over 600 lbs of torque. He can roll off the line in 3rd gear.

Things to note: 4 inch bore by 4 inch stroke is the most efficent combination. 11:1 compression yields best fuel milage. 2500 feet per minute is the ideal flow rate through intake ports. Manual transmissions are best for milage. Small blocks are horsepower motors and need to turn high rpm to make any power while big blocks make it down low. Big rod:stroke ratios are good. You will probably need fuel injection in order to make enough low end for the kind of overdrive you want to run, and it will also help with milage. V-8 is the most fuel efficent engine design per cubic inch, more so than 4 and 6 cylinder engines. Pontiacs are good because they have long rods, but Chevy motors are very light.

Be prepaired to use a calculator.

Thank you for your help! Im going to try some of your ideas.