How do I Increase Horsepower on a 440 Dodge Engine?by Richard RoweUpdated November 07, 2017
Items you will need
Basic hand tools
Roots-Type Supercharger Kit
Dodge's 440 cubic inch B/RB big block was a standout engine of its time, in many ways defining the muscle car's golden era and only just outliving it. The 440 "Max Wedge" powered some of Chrysler's most legendary automobiles, but by 1972 had lost most of its punch through reduced compression and additional emissions equipment. However, even the lowest-performance smog-era 440s have enormous potential just waiting for you to unleash it with one massive, old-school supercharger.
Send your engine to a machine shop to have it disassembled, cleaned and checked for cracks. Have the machine shop perform any required machine work, including (but not limited to) cylinder boring, align boring, cam boring, and block and cylinder head decking. Of these, cylinder boring and decking (milling the block and cylinder head mating surfaces flat) are the most crucial for this application.
Choose a supercharger-specific camshaft with a wide 114-degree lobe separation. You'll want to use a split-pattern camshaft with about 0.080-inch more lift and about 4 degrees more duration at 0.050-inch lift on the exhaust side than the intake. For a street engine with a stock crankshaft, purchase a cam designed to deliver power in the 3,500 to 5,500 rpm range. If you don't want to use a supercharger-specific cam, use a standard cam with 1.5-to-1 roller rocker arms on the intake valves and 1.7-to-1 rockers on the exhaust valves.
Purchase a set of 4340 steel I-beam connecting rods and forged pistons intended to deliver between 8.5 and 9.0 to one compression with your stock cylinder heads. Have the machine shop balance the rotating assembly (crankshaft, rods and pistons). If you're already having the block machines and the assembly balanced, you might as well pay the machine shop to assemble the long block (block and heads) for you. This will probably only add a few hundred dollars to the overall cost--a price well-justified by the peace of mind that a warranty brings. Have the machine shop install the mains with chrome-moly studs and the heads with Cometic gaskets and chrome-moly head studs.
Bolt the supercharger-specific lower intake manifold to the heads and bolt the supercharger to the manifold. Superchargers in this class are rated as either 6-71, 8-71 or 10-71; this rating system hearkens back to the days when hot-rodders took their superchargers from massive six, eight and ten cylinder diesel engines. Each of the engine's cylinders displaced 71 cubic inches, thus the rating system. A 6-71 blower will work for this application, but you'll probably be better off with an 8-71. Install the supercharger as per the kit instructions.
Top the engine off with a pair of 450-cfm, vacuum-secondary carburetors, an aftermarket distributor and coil, an ignition box with provisions for boost-regulated timing retard and a set of 2-inch primary headers.
An engine built to this spec can produce anywhere from 500 horsepower to 900 horsepower, depending on how much boost you choose to run. A smaller crankshaft pulley and larger supercharger pulley will drop boost, while the opposite will raise it. Five psi of boost should net you about 540 horsepower, seven psi should be worth about 600, and 11 psi should be worth about 700. For anything over about eight psi, you'll want you use a water/alcohol injection system to cool the intake charge and prevent detonation.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.