According to Burcham, the boost was kept to 10 psi due to the fuel system. The engine and Paxton blower were ready for nearly 20 psi of boost, but the car still had factory fuel lines and rails, and not enough fuel pump to supply the proper volume of gasoline. The injectors are Ford Racing 60-lb/hr pieces.
The final tally was 508 rwhp with a rather mild 10 psi of boost.
as the bore size increases, so dees the cfm flow as it unshrouds the valves by moving the cylinder wall away from them We didn't test a set of LH 195cc heads, but Brodix touts them as moving 287 and 294 cfm at 0.500- and 0.600-inch, respectively. The exhaust ports in the 195cc version flow less due to less porting—209 and 213 cfm at the two big lift numbers of 0.500- and 0.600-inch.
"Pay attention to the flow numbers in the mid- and low-lift areas when selecting a cylinder head. Too often people focus on the peak number, which is usually at 0.700-inch lift. That result doesn't matter when your cam has a max of 0.500-inch. The mid- and low-lift results are more important—during combustion a valve travels past the 0.100, 0.200,0.300, and 0.400 ranges twice and only hits the peak once," notes Burcham.
Another nice aspect of the Brodix LH heads is the valve angle. "The valve is at a 17-degree angle in relationship to the bore or piston travel," said Neugent. The stock 5.0-liter heads feature a 20-degree valve angle, and Brodix stood the valves up by 3 degrees to help the air and fuel distribution. But Neugent cautioned that it isn't as simple as just moving the valve angle in the head. The port locations are also critical in distributing the air and fuel into the combustion chamber.
The guys at JPC Racing bolted the heads back on with a few extra parts and pieces needed for the installatioa Cometic provided its MLS (multilayer steel) head gaskets, and a set of replacement intake and exhaust gaskets. The heads were secured to the Boss 302 block with ARP Va-inch studs, which we procured from Summit Racing. Comp Cams came through with a set of its 16 roller rocker arms and new pushrods.
The swap was straightforward, and before we knew it, the car was back on the dyno. The new heads helped the engine breath easier, and Burcham dialed in the tune using a DiabloSport chip in the stock A9L computer. The result was a better 508 rwhp at 6,400 rpm and torque of 425 lb-ft. The better flowing heads helped feed the hungry 331ci, and also showed that better flowing heads also make a difference in a supercharged application.
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