High-Flow Pontiac Cylinder Head Packages - Cylinder Head Symphony

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Frank Gostyla and Bob Cacciotti opened AllPontiac.com in Richmond, Virginia, in 2003, in the hopes of providing Pontiac hobbyists with components that are capable of generating big-block Chevy-type performance. "We felt too many racers were getting away from Pontiac power, and our goal was to produce a high-flow cylinder head that would allow a large-displacement Pontiac engine to compete with a comparable big-block Chevy on the drag strip."

Gostyla tells HPP that among his company's first projects was seeing the Tiger cylinder head into production, but he's quick to admit that Don Johnston, of DCI Motorsports, was responsible for its initial design and development. "We purchased the tooling and rights from DCI in August 2006, forged onward, finalized the product, and marketed what's available today."

The Tiger head is available as a bare casting that contains valve seats and guides, but no additional machining, for $2,395 per pair. "Our bolt-on packages seem most popular, and we offer two variations-our Pump Gas package starts at $5,000 per pair, while our Race Ready package starts at $5,850," states Gostyla.

Both packages include 2.25/1.80-inch valves and a wide array of high-quality Manley valve-train components designed for the rigors of a mega-lift solid roller cam-shaft. The pump-gas casting includes stainless steel in-take and exhaust valves and Harland Sharp 1.7:1 roller rocker arms, while the race-ready package boasts titanium intake valves, and a Jesel 1.8:1 ratio rocker shaft system.

The as-cast intake port measures 310 cc, and airflow peaks at 414 cfm at 1.00-inch valve lift, at 28 inches of pressure. "Port velocity is very important, and we've found that it's extremely high in our casting," says Gostyla. "That likely contributes to the strong torque numbers we're seeing, but we've been careful, too, since too much port velocity at higher lift can induce turbulence.

"Our Tiger head requires the Tiger intake manifold, which is a single-plane casting with a Dominator-style flange, but we also offer intake flange adapters for use with conventional intake manifolds. The as-cast exhaust port flows 73 percent of the intake port, and while we don't presently offer any additional intake or exhaust porting, we do offer two distinct exhaust port configurations-one accepts typical round-port headers, and the other is a raised port design."

Fast-burn style combustion chambers of the Tiger castings are CNC-machined, and displace 66 cc of volume, which yields a compression ratio of about 15:1 on a typical 511ci engine. "We don't offer any other sizes at this time and, instead, manipulate compression ratio with dished pistons-a 37-cc dish drops that towards 10:1," Gostyla states.

The Tiger head requires a minimum bore diameter of 4.31-inches, like that of the aftermarket IA-II block, which AllPontiac.com happens to produce. "Dyno testing has shown that on a typical 511ci engine with a Tiger intake manifold, our cylinder head consistently produces 900 to 950 horsepower between 7,000 and 7,500 rpm, with torque peaking between 5,000 and 5,500 rpm. We've also seen, in a maximum performance application, that after porting to 445 cfm, our Tiger head has produced 1,170 horsepower and 860 lb-ft on a 565ci engine. That's enough power to seriously compete with a big-block Chevy on the dragstrip," says Gostyla.