Holiday torqued the heads...
Holiday torqued the heads down to 105 lb-ft with moly lube. The high torque rating was due to the 1/2-inch studs. He started with just 40 lb-ft and began in the center and worked his way to the outer ones. Holiday then hit each with 70 lb-ft of torque using the same inside/outside technique. The final go around was done to 105 lb-ft.
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 installation. Cometic provided its MLS (multi-layer steel) head gaskets, and a set of replacement intake and exhaust gaskets. The heads were secured to the Boss 302 block with ARP 1/2-inch studs, which we procured from Summit Racing. Comp Cams came through with a set of its 1.6 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.
The new heads required different...
The new heads required different length pushrods. We picked up a set of Comp 6.450-inch pushrods for use with the Brodix heads.
Comp Cams Pro Magnum 1.6:1...
Comp Cams Pro Magnum 1.6:1 roller rocker arms were used on both sets of heads.
Holiday put the lower intake...
Holiday put the lower intake manifold on the Brodix heads and checked to make sure the ports lined up. Everything fit perfectly.
The intake was torqued down...
The intake was torqued down using 15 lb-ft.The same inside-outside technique from the head torque sequence was used when bolting down the intake.
According to Burcham, the...
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.
Brodix also sent us a nice...
Brodix also sent us a nice set of cast-aluminum valve covers and Holiday had to add breathers to each cover.
The top-half of the engine...
The top-half of the engine was bolted back on, and the Paxton Novi 2200 blower was almost ready to start providing boost to this engine.
The final tally was 508 rwhp...
The final tally was 508 rwhp with a rather mild 10 psi of boost.