High-Flow Pontiac Cylinder Head Packages - Cylinder Head Symphony
In the previous issue, we spoke with a number of well-respected companies that market high-flow Pontiac cylinder head packages, and each shared with us the detailed specifications of those aimed at enhancing the performance of moderately-sized street and street/strip engines. We also learned that the round-port castings Pontiac produced during the late '60s and early '70s were each designed to complement its specific application.
This installment will follow suit, except we'll explore the specialized offerings from a wider range of companies. While most are designed to maximize the performance of street/strip and full-race engines displacing more than 450ci, there are certainly a number of hobbyists using them successfully in dedicated street applications. The companies have shared with us their casting's major advantages, installation requirements, and expected performance levels. Follow along as we conclude our two-part series.
SD Performance's Moderate Monsters
Dave Bisschop of SD Performance in Chilliwack, British Columbia, has developed a strong reputation for his moderate approach towards serious performance. The company's cylinder head packages are a key element of that success, and SD Performance has recently incorporated a computer-controlled mill to increase internal efficiency. Bisschop has not only created successful porting programs for various cast-iron D-port cylinder heads, but also for the aftermarket Edelbrock aluminum casting.
Few would disagree that in box-stock form, a basic Edelbrock cylinder head is adequate for many mildly-built, moderate-displacement Pontiac mills, but Bisschop says that today's trend leans toward large-displacement, pump-gas engines, and he feels that a stock Edelbrock casting can sometimes become a limiting factor in those applications.
"Today's hobbyists seem to enjoy driving their Pontiacs on the street during the week, and then going to the track and running well on weekends-and the most reliable way to achieve that balance is with a large engine. Displacement starts around 470 ci when adding a stroker kit to an otherwise typical 400 rebuild, and it can reach well into the 500s with an aftermarket block. We've found these engines typically respond favorably to additional airflow, so we developed bolt-on CNC-ported Edelbrock packages for them."
SD Performance markets three distinct packages that begin life as a semi-machined 72-cc Edelbrock casting. "We CNC-machine its intake and exhaust ports, and enlarge the combustion chambers as necessary. Our basic 310-cfm package increases as-cast intake port volume from 215 cc, to 235, and boosts airflow from roughly 280 cfm, to 310 at 0.600-inch, at 28 inches of pressure. Pricing starts at $2,300 per pair. Our 330-cfm casting, which peaks at 0.700-inch, starts at $2,400 and is probably our most pop-ular. Many hobbyists recognize its economic value and are willing to spend the extra $100 for 20 additional cfm."
According to Bisschop, both packages boast of such standard features as 2.19/1.77-inch stainless-steel valves, multi-angle valve seats, dual valve springs suitable for either type of flat-tappet camshaft, or a hydraulic roller, and include a host of other top-quality valvetrain components. Solid roller valvesprings are optional on the 330-cfm casting only, and add $100 to the final cost. The exhaust port of either casting typically flows 70 to 75 percent of the intake port.
The third CNC-ported Edelbrock package SD Performance presently offers is its wide-port casting. "We typically limit it to competition applications," says Bisschop. "Measured airflow is at least 370 cfm at 0.750-inch lift, and base price starts at $3,000. The castings feature 2.25/1.74-inch valves, and the intake ports, which measure 267 ccs, require the use of a 11/42-inch offset rocker shaft system and our similarly-modified Victor intake manifold, or a cast-aluminum unit from BOP Engineering-all of which we offer at extra cost."
Combustion chamber volume is one area of any Edelbrock package that's machined to customer order. "We've developed CNC programs that can increase the volume of a 72-cc casting towards 90 for $150, and have just released our "heart-shaped" chamber option. We weld mat-erial into an otherwise typical chamber, and then machine it into its final shape, which measures in the low 70s. Our testing indicates a definite efficiency improvement."
Bisschop tells HPP that he's happy with the dyno testing results so far, but expects to extract additional horsepower from his castings in the future. "We're finding our 330-cfm casting is presently generating around 700 to 750 horsepower on a 470ci engine with 12.5:1 compression, a solid roller camshaft, and a Victor intake manifold. Increase displacement to 541, and compression to 14:1, and we're consistently producing anywhere between 850 to 900 horsepower with our 370-cfm wide ports."
Kauffman Racing Equipment's High Port Hysteria
If you've read the previous installment, you're familiar with the effort that Kauffman Racing Equipment, in Glenmont, Ohio, set forth when producing its aluminum D-port cylinder head. With its relatively small as-cast intake ports, and optional porting, it serves a broad market segment, but its D-port exhaust configuration can be somewhat limiting, so KRE introduced another casting aimed at additional performance from larger displacement mills.
"Our aluminum D-port was developed to fulfill one need, and we felt there was similar need for a direct-replacement to the stock castings in larger, street and/or strip applications, so we developed our High Port cylinder head," Jeff Kauffman says. "To make installation as easy as possible, we included a standard Pontiac intake flange and round-port exhaust configuration, and pushrods that are in the stock location."
Bare castings include valve seats and guides, and pushrod guide plates for $1,495 per pair, but Kauffman says his bolt-on High Port packages are most popular. Prices begin at $2,400, and include 2.20/1.70-inch Ferrea 1200-series valves, 1.625-inch diameter valvesprings that are compatible with solid roller camshaft lift up to 0.750-inch, 10-degree steel valve locks, titanium retainers, and 71/416-inch ARP rocker studs.
Like the D-port, Kauffman says that port velocity was a key element of the High Port's design. "We want to produce peak torque as early as possible, and then build horsepower from that, so we designed a highly-efficient intake port." In as-cast form, its intake port measures 277 cc, and airflow peaks at 330 cfm at 0.700-inch lift, at 28 inches of pressure. "We can increase peak airflow to a maximum of 400 cfm at 0.800-inch lift, with our optional CNC-porting programs, which subsequently increase maximum port volume to 330 cc," he adds.
The exhaust port flows roughly 70 percent of the intake port, and it, too, is CNC-ported to maintain said percentage as intake flow increases. "We use 2.25/1.75-inch diameter valves when additional flow is needed, and though it accepts standard rocker studs and roller rocker arms, a stud girdle or rocker shaft system is available at extra cost. A rocker shaft is, however, required with the 400-cfm casting," adds Kauffman.
Designed for a minimum bore diameter of 4.15 inches, Kauffman claims that an as-cast High Port is capable of producing 650 to 700 horsepower on a 455 with 13:1 compression and a single four-barrel carburetor. "If we push the displacement to 500ci, and add a Victor intake, we're seeing on our dyno about 750 hp at 6,400 rpm in as-cast High Port, and about 900 hp at 7,000 rpm from a 400-cfm casting."
If that weren't enough, it appears that yet another cylinder head casting is on KRE's horizon. The company is presently testing a splayed, canted-valve cylinder head, and Kauffman says he's extremely excited with the results from testing the billet-aluminum prototype. Expect additional coverage if and when the casting reaches production.
Roland Racing's Radical Replacement
Jim Sammons opened Roland Racing in Springfield, Missouri, just a couple of years ago, but that doesn't mean he's a beginner. Sammons' previous career was designing valvetrain components for overhead valve engines. He was employed by a major manufacturing company that continues to supply General Motors and Ford today, and his enthusiasm for the Pontiac V-8 led to the development of a canted-valve cylinder head for that application.
"I wanted to create an out-of-box high-performance Pontiac cylinder head that's comparable to what's available for other big-block engines," says the once-Detroit-based application engineer. "I started with a clean slate and designed an entirely new casting using an automated computer program. My experience with canted valve angles led me to follow that path, and the CV-1 was developed."
Canted angles typically reduce the shrouding that otherwise occurs when valves are located too closely to a cylinder wall, and Sammons' particular design allows the use of larger valves within a traditional Pontiac bore diameter. "Combine that with a properly designed intake port that directs airflow toward the middle of the cylinder, and the performance advantages are quickly apparent," he adds.
While Roland Racing offers bare castings that include valve guides and seats for $2,495, the company will soon offer a complete bolt-on package that starts at $2,995. "I wanted to keep it simple, so I sourced a lot of off-the-shelf components to maintain affordable pricing. I have, however, left lots of material around the valves, and in the ports, so engine builders can tailor the CV-1 to specific applications."
The basic CV-1 package includes 2.25/1.66-inch stainless-steel valves and, while Sammons says he doesn't plan to offer larger valve sizes, the castings can easily accommodate 2.30/1.71-inch units. "Standard valvesprings are conical, single-wire pieces designed for solid flat-tappet and hydraulic roller camshafts with lift up to 0.700-inch. The rocker studs and arms, and pushrods we suggest for either application, are mostly off-the-shelf big-block Chevy components."
Sammons says he concentrated heavily on optimizing mid-lift port efficiency (0.400- to 0.700-inch) during development, and that the CV-1 intake port measures 290 cc, and flows around 380 cfm at 0.800-inch lift, at 28 inches of pressure. He adds, "While intake port volume may seem large, the actual cross-sectional area is comparable to a 308-cc big-block Chevy head. The CV-1 requires a minimum bore diameter of 4.15 inches, and engines displacing at least 450 ci should be more than comfortable with the port volume. We expect peak power to occur around 7,000 rpm in short-stroke applications, while longer-stroke engines should pull the peak down a few hundred rpm."
While a unique intake manifold is required due to the canted valve angles, the exhaust configuration is much more conventional. "The exhaust port flows around 70 percent of the intake port, and the casting accepts a typical round-port header," he says. "We can also mill the down-turn from the exhaust runners, all the way to the water jacket face, creating a 'convertible' port for those building headers for tube-chassis or turbocharged applications."
Sammons tells HPP that he's invested more than 3,000 hours into the project, and hopes to have production units available by the time you read this. "The response so far has been incredible," he states. "We have several independent builders waiting to perform their own tests with them, and I'm confident that the horsepower and torque numbers will be comparable to those of an equal-priced big-block Chevy. I sincerely believe that the CV-1 will provide Pontiac hobbyists with a horsepower-per-dollar ratio that the Chevy crowd has enjoyed for years."
Butler Performance's Wide Port Wonder
Butler Performance in Leoma, Tennessee, is among the most recognizable names within the Pontiac hobby, and the Butler family has spent years testing myriad combinations to find those that are most successful to offer to its customers. David Butler says that, while his company offers and/or modifies virtually any original or aftermarket casting presently available, he feels that BP's Wide Port Edelbrock cylinder head is among the very best for serious performance applications.
"We spent a lot of time on the dyno and dragstrip searching for a highly-efficient intake port, and began marketing our Wide Port package in the late '90s. At the time, the castings were all hand-ported, but we're now using a CNC mill to perform most of the port work. The consistency of Edelbrock's casting has always been great, and once we developed our CNC program, only a small amount of hand-finishing was required."
Butler says that the Wide Port starts life as a semi-machined 72-cc Edelbrock casting that's prepared similarly to the hand-ported offering featured previously. "We keep plenty of machined castings in stock and build to order. Its combustion chambers are polished, and oil return holes are modified to promote quicker drain back. We then finish and assemble it to match each customer's specific application."
Base price for the bolt-on Wide Port package begins at $3,595. That includes 2.19/1.77-inch stainless-steel valves, solid roller valvesprings, and Comp Cams retainers and valve locks. The intake port measures around 275 cc, and airflow peaks near 370 cfm at 0.750-inch, at 28 inches of pressure. The exhaust port flows roughly 70 percent of that value.
Because of added intake port width, the Wide Port requires the use of a few non-conventional components-all of which BP stocks. "The required solid roller lifters are offset 0.18-inch, and we suggest an offset T&D rocker shaft system. Aftermarket intake manifold choice is presently limited to our custom sheetmetal or a Wide Port-modified Edelbrock Victor, BOP Engineering's cast-aluminum four-barrel, and Wenzler's Gutsram," he adds.
Even after polishing, combustion chamber volume remains around 72 ccs. "We can mill the deck surface to reduce chamber volume into the mid 60s, or enlarge the existing chamber up to about 80 ccs," Butler says. Since Edelbrock isn't presently offering a semi-machined version of its 87-cc casting, BP doesn't mass-market a larger-chamber Wide Port. Butler adds, however, that if a customer is willing to accept the added expense of modifying an 87-cc casting, the company can certainly create a large-chamber Wide Port, too.
Butler feels his company's Wide Port casting is very versatile. "We suggest a minimum bore diameter of 4.15 inches, and have used it in applications that range from high-performance-street to full-race. It's most popular on engines that displace at least 467ci, and we've been very satisfied with the results. We're seeing around 800 hp at 6,500 to 6,800 rpm from a typical pump-gas 500ci engine with 11:1 compression, and a Victor intake manifold. Add a tunnel port intake and compression that's near 15:1, and we're consistently seeing over 900 hp at 7,000 rpm."
Allpontiac.Com All Star
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.
Wenzler's Warrior
Larry Wenzler of Wenzler Engineering in Oak Creek, Wisconsin, has been producing Pontiac cylinder heads for nearly two decades, and his original round-port was among the first aftermarket cast-aluminum units ever made. Though that same basic cylinder head is presently marketed as the Series II, it's the high-flowing Super Chief that carries Wenzler's torch in today's hardcore performance market.
"We recognized that large-displacement engines built with aftermarket blocks needed at least 400 cfm to take advantage of the available horsepower potential, so we developed the Super Chief to meet that challenge. We started from scratch and created a unique casting that we feel is best suited for a bore diameter of at least 4.375 inches," Wenzler says.
Since most customers in the Super Chief market segment prefer to tailor cylinder head assembly to fit the unique needs of a specific combination, Wenzler says he delivers the castings in a semi-complete state, which includes valve seats and guides, and CNC-machined combustion chambers, with prices that start at $1,250 per pair.
The Super Chief boasts of raised and widened intake ports, which are said to flow around 320 cfm at 0.600-inch lift in as-cast form. "We offer optional hand-porting that can increase that number to more than 400 cfm, but flow as high as 430 cfm has been attained," Wenzler says. "We suggest 2.25/1.80-inch diameter valves, but the intake bowl contains enough material to increase that valve to 2.3 inches." While the casting has been used successfully with as little as 4.25-inch bore diameter, he adds, "Valve shrouding can become a concern at that point."
Wenzler says the Super Chief works best with his Gutsram intake manifold, which is a unique high-flow design. "This head is cast with runner extensions, so a conventional intake manifold can be used as long as its port size matches. The exhaust port, which flows roughly 70 percent of the intake port, features a typical round-port exhaust flange, but its outlet has been raised to improve airflow, and requires custom-built headers."
The additional intake port width requires 0.18-inch offset lifters and, due to this, Wenzler suggests that the Super Chief be used with solid roller camshafts only. He also notes that traditional rocker arms are not an option. "We designed the Super Chief for use with a T&D rocker shaft system, which we offer for an additional $850, when ordered with the cylinder heads."
Wenzler feels his Super Chief is among the best in its price range and, when combined with his tunnel-ram intake, is an inexpensive way to extract horsepower from large displacement engines. "It has the potential to produce some serious power. Our 430-cfm castings have made 1,075 hp and 770 lb-ft of torque on a 517ci engine-and that's hardcore performance that's backed by track-proven results."
While other engine builders and/or cylinder head specialty shops are certainly capable of producing airflow and/or performance numbers similar to those discussed in our two-part series, few have invested the resources necessary to market such packages on a grand scale. With so many high-quality packages covering such a wide application base available today, it's no mystery why a growing number of hobbyists are no longer attempting port work at home. So the next time you find yourself in the market for high-flow Pontiac cylinder heads, consider the packages featured in our two-part series, and you'll likely find what makes them so attractive!

Photo Gallery: High-Flow Pontiac Cylinder Head Packages - High Performance Pontiac Magazine

Read More | Digg It | Add to del.icio.us