Performance Cylinder Heads
By Larry Carley
It’s a no brainer. You can spend hours hand porting, flow testing and developing a set of stock OEM heads to gain another 100 or so horsepower, or for $1,000 bucks or less you can bolt on a set of ready-to-go aftermarket heads that probably out perform your hand ported heads right out of the box. More and more engine builders are opting for the latter because it’s easier, quicker and involves fewer risks.
Aftermarket performance heads run the gamut from fully assembled street legal replacement heads to bare CNC machined castings for all-out racing applications. Prices have tumbled as more and more companies have jumped into the aftermarket cylinder head business. Yet in spite of all the competition, all the companies seem to be doing well. Every supplier interviewed for this article said sales were strong and demand was up.
More good news for you is the fact that these companies are offering a wider selection of heads than ever before. It’s not just your traditional small block/big block Chevy and Ford heads. It’s also late model Chevy LS1 and Ford 4.6L heads, Pontiac, Oldsmobile, Mopar and AMC V8 heads, plus a bunch of new heads for everything from Honda four cylinders to GM’s 2.2L Ecotec engine. The companies are responding to what the market demands, and as a result engine builders have more and more options from which to choose.
Bare castings have always been popular with professional engine builders because they allow you to do the final finishing and/or additional porting and tweaking as needed. Some companies are offering partially CNC machined heads as well as fully CNC machined heads for those who want the utmost in performance. CNC machining typically adds about $1,000 or so to the cost of the base castings.
It’s no secret that heads make horsepower. But to maximize performance and driveability for street applications, the heads have to be matched to the engine application, the camshaft, valves, fuel delivery system and drivetrain.
Street engines need low end torque, especially in heavier vehicles and ones with automatic transmissions. This, in turn, requires higher air velocity through the ports so the cylinders will fill completely at lower rpms. If the ports are too large, the engine won’t breathe as well and won’t pull very strong at lower rpms – which may not make your customer very happy.
Selecting the proper runner size, therefore, is critical to building an engine that delivers power and torque in the right rpm range. For most street applications, you typically want the engine to develop peak power in the 1,500 to 5,500 rpm range.
For all-out performance, maximum airflow at higher rpms is what counts. This requires huge ports and valves that can pass more gas than a politician on election eve. Low end torque isn’t as important so the sky is the limit when it comes to big flow numbers. CNC machined bare castings are, in many cases, usually the way to go.
CNC machined port, bowl and combustion chamber configurations are typically based on head configurations that have been proven on the flow bench, dyno and race track. Once the port, bowl and combustion chamber configurations have been perfected for a certain application, the head can be plotted with an electronic probe that converts the profiles into a digital map. The numbers are then fed by computer into a 5-axis CNC milling machine which grinds away the metal to create an exact duplicate of the winning head.
What used to take days or even weeks to do by hand can now be accomplished in a couple hours or less on a CNC machine. Better yet, it allows any port configuration to be easily copied and duplicated – which means racers on a budget can afford almost the same level of technology as those with deep pockets.
A pair of hand ported state-of-the-art Pro Stock heads can easily cost $18,000 to $20,000 or more to develop because of all the research time it takes to massage maximum power out of the heads. These kind of heads are usually custom made for a particular racing team so the volume is very low (maybe only a few sets a year). The profiles are also kept secret for at least a season or two so the competition doesn’t copy the design.
However, once the heads have served their purpose and are superseded by the next generation head, the old port profiles can be mapped and duplicated with CNC equipment and offered in mass produced heads for a fraction of the cost. Thus, it’s possible to buy CNC machined racing heads that are essentially copies of winning head designs for a few thousand dollars.
Hugh Baskin of Patriot Performance, Alabama Cylinder Head Inc., Rainbow City, AL, says Chevy LS1 heads are hot. "A lot of people want these heads, so we bought 4,000 LS1 castings from GM and are CNC porting the heads and assembling them with our own valves." He said the LS1 heads retail for about $1,295 a pair, exchange through distributors.
"We’re also doing Ford 4.6L heads and GM’s 2.2L Ecotec head, which we think will be the next big thing in this market. The Ecotec engine is in Chevy Cavaliers, Pontiac Sunbirds and Grand Ams, Saturns and other GM models. We have 500 new Ecotec castings which we are CNC porting and offering with stock-sized valves, 5-angle valve job but no camshafts."
Baskin said Patriot Performance is also developing a number of new cylinder heads, including one for the Ford Focus based on a CNC ported version of the OEM head. They’re also doing a Chevy 350 head, which will be custom cast and fully CNC machined to various specifications (180, 200, 215 and 235 cc runner sizes). They are also looking at the Jeep 4.0L and possibly some Honda and Acura engines, too.
I see the cylinder head market going in two different directions," said Bill Mitchell of Bill Mitchell Racing, World Products, Sterling Heights, MI. "The aftermarket has to keep making replacement heads for V8 engines that Chevy, Ford and Chrysler no longer make. These are mostly heads with stock configurations. The other trend I see is where the aftermarket doesn’t have to follow any rules; where it can make any kind of head for any engine. There can be hemi heads for Fords and Chevys, not just Mopars," he says.
"As for stock heads, World Products has long made heads for small block and big block Chevys, and small block Fords. We don’t have any Chrysler heads yet or big block Fords, but both are in the works," said Mitchell.
World Products offers heads in both aluminum and cast iron. For street engines, Mitchell recommends cast iron heads over aluminum. "Iron is better where weight or looks are not a factor because it retains heat better than aluminum and keeps the heat in the combustion chamber, which is where you want it. Cast iron heads will typically give you about 10 to 15 more horsepower than an identical set of aluminum heads on a street engine. As for the weight difference, a pair of cast iron small block Chevy heads weighs about 30 lbs. more than a set of aluminum heads. On a big block Chevy, the weight difference is about 85 lbs. – which doesn’t make much difference on a crew cab truck or RV, but does in a race car. For racing, you’d want the lighter aluminum heads."
Mitchell says a lot of people are selling both stock and performance aluminum heads these days, but not many are selling cast iron heads. The reason is cost. The tooling costs for a cast iron head typically cost seven times as much as that for an aluminum head, $750,000 versus $100,000.
Cast iron tooling is also designed for higher volume production, say one head every 12 to 15 seconds versus maybe eight to 10 heads a day with aluminum. Consequently, the volume must be there to justify tooling up for a cast iron head.
What about performance cylinder heads for sport compact vehicles? Somewhat surprisingly, Mitchell says he doesn’t see a viable market yet. He says it’s more of a "lifestyle thing" than a real hard core racing market.
"The compact sports car events at drag strips attract a lot of interest, but the people who go are there to watch the races and don’t really care if they are drag racing themselves or not," he says. "It’s more of a social event. It’s great for the race tracks because the fans buy lots of hamburgers and T-shirts. But they’re not buying engine parts. The only guys doing that are the 25 or so hardcore racers in the country."
Mitchell explains his skepticism over the sport compact performance craze: "We watched dune buggies and vans come and go. If the sport compact market is still around in another five years, it’s probably something that would be a viable market to produce heads for. But it’s pretty hard to improve on the stock OEM Japanese heads."
Brodix, Dart and Edelbrock have all introduced new and improved cylinder heads for small block and big block Chevys and small block Fords. These engines represent the lion’s share of the performance market and continue to generate strong sales.
Jeff Brotherton of Brodix, Mena AR, says his company has a new 180 cc runner "Pro Street" head and 200 cc runner "Race-Rite" head for small block Chevys, a new 18 degree oval port pro stock style head for big block Chevys, and symmetrical port 13-1/2 degree and 12 degree small block Chevy heads for dirt track, nitrous and 10-1/2 inch tire drag racing classes.
Brotherton says Brodix does everything in-house, from casting the heads to machining and repair work. Offerings run the gamut from stock to fully ported race heads. The least expensive street heads typically sell for around $1,000 a pair while fully ported bare racing heads go for up to $5,000 a pair.
Dave Bieneman of Dart Machinery Inc., Troy, MI, said Dart has four new heads, including new CNC machined aluminum heads for 302/351 Fords with 210 cc or 225 cc runners. These are a standard 20 degree head for use with stock rockers and manifolds.
"We also have a new Little Chief splayed valve 11 degree small block Chevy racing head that flows 430 cubic feet per minute," says Bieneman. The head is designed exclusively for use on Dart’s bored and stroked small block iron or aluminum block Chevy engines, he says, and requires a special intake manifold and valve covers
"Another new product is our Big Chief One Pro Stock head that is sold as cast with unfinished ports. We CNC machine the bowl and combustion chamber but leave the ports alone so the customer can do his or her own porting. These heads are for big 580 to 600-plus cubic inch motors and marine racing applications. The price is $2,500 a pair," Bieneman says.
"We’re also coming out with a Big Chief Two Pro Stock head for big block Chevys of 500 cubic inches and up," he continues." The head can handle a valve lift of up to one inch. The bare heads come with beryllium seats and sell for $5,000 a pair."
Bieneman said Dart is also CNC machining brand new Honda heads, which should be available by the time this article is published. The Honda heads will be sold outright (no exchange).
"We may eventually come out with a Honda performance head of our own design, but the market isn’t quite ready yet," said Bieneman.
Steve Wipple of Edelbrock, Torrance, CA, said Edelbrock’s new products include a new big block Chevy racing head for 1200 to 1300 horsepower all-out racing engines, a new Chevy LT1 cylinder head for 1992-’97 LT1 engines with 170 cc intake runners and 54 cc combustion chambers, and a new street-legal AMC head for 304/360 V8s.
Wipple said Edelbrock has been watching the potential market for Honda heads, but has not made any commitments yet.
Kevin Feeney of Pro Topline, South Auckland, New Zealand, says Pro Topline offers a complete line of stock replacement heads for both import and domestic engines, cast iron and aluminum "Torquer" street/strip performance heads for small block and big block Chevys and small block Fords, and high end full CNC machined 14 degree small block Chevy high port heads.
"I see the market moving more toward out of the box cylinder heads. The casting technology is so advanced today that as cast heads have less need for porting," says Feeney. "We can offer various runner volumes and combustion chamber configurations. Of course, for those who want it we also offer partially and fully CNC machined heads."
One new product Pro Topline is introducing is a new aftermarket performance head for Honda. The head will be available in GSR and Type R configurations, and can be purchased as-cast or fully CNC machined. The retail price for the as -cast head will be $1,099 and up depending on the valvetrain options, and $2,495 for the CNC machined head.
Bob Christopher of Engine Parts Warehouse, Louisville, KY, says there is such a proliferation of aftermarket heads to choose from today that a lot of people are confused. "That’s where we can help. We carry Dart, Brodix and Pro Topline heads and can help our customers choose a head that’s right for their engine. Matching the runner volumes and combustion chambers is very important. We know what works and what doesn’t. The key is putting together the right combination of parts.
"Some engine builders are trying to emulate the Winston Cup approach by using cams with smaller lobes but higher lift rockers. That approach doesn’t always work," says Christopher.
Christopher says one of the hottest markets for performance heads right now is circle track racing. Many rules require flat top pistons so racers want smaller 49 cc combustion chambers to increase compression.
Christopher said Engine Parts Warehouse will CNC machine heads and offers a semi-modified Dart head with reworked combustion chambers and CNC machining 1-1/2 inches into the ports. This is good for about 20 cfm more airflow through the intake ports and an 11 percent improvement on the exhaust ports. The partial CNC machining costs $875. Fully CNC machined Dart heads are also available with 200 cc and 227 cc intake runners. The fully machined bare heads sell for $1,600 a pair.
Joe Costanzo of Liberty Engine Parts, Philadelphia, PA, says the sales of performance heads are pretty good overall. "Bad weather on the East Coast has hurt the sales of performance parts because a lot of circle track races have been rained out. Even so, it hasn’t had much effect on the street/strip market."
Costanzo says most of his customers are buying bare heads and valves separately, but some customers are buying assembled heads. "Most of our customers have done their homework before they call and know exactly what they want. But some haven’t heard of Pro Topline because it’s a new brand so they may ask for more info before making a decision." Liberty carries Dart, World and Pro Topline heads.
Dusty Dodge of Engine and Performance Warehouse (EPW) in Denver, CO, says performance heads are a natural add-on sales opportunity for engine builders. "If you’re rebuilding an engine, upgrading to aftermarket performance heads is an easy step up. We try to be as price competitive as possible with our products and we have 11 branch locations in the western U.S."
Dodge says EPW sells mostly cast iron heads for SB/BB Chevys and SB Fords. Intake runner volumes range from 165 cc to 220 cc. Most of the heads sold are for street performance applications but also some circle track engines.
"The market for performance heads overall is probably flat right now, but our sales are up over last year. For us, the performance heads complement our other engine parts and kits. By carrying three different lines (World, Dart and Pro Topline), we offer our customers a choice. They decide what they want, not us," explains Dodge.
Pro-Filer Performance of New Carlisle, OH, sells its own brand of aluminum performance heads. Michael Green says his product line includes a 24 degree BB Chevy head with 290, 320 and 350 cc cast runners, a 12 degree spread port BB Chevy head, a 23 degree SB Chevy head with 210 cc intake runners, and a BB Ford C460 head. Heads are sold bare or assembled.
"We don’t CNC machine our heads because we use a casting process that delivers a very smooth finish. Our as -cast ports don’t really need any additional machining and flow better out of the box than most competitive heads," says Green.
Green says Pro-Filer Performance is busier than last year and there’s been no slow down in demand. Customers are using their heads for street/strip, drag racing, truck pulls, oval track and marine applications.
Performance cylinder heads are available to meet your customers’ needs – you just need to look for them in all your favorite places.