Photo Credits: Wayne Scraba
The advancements in today’s race engine technology have led to performance improvements once thought completely impossible. The big key has to be cylinder head development. Not that long ago, performance gains in the cylinder head department were the result of extremely expensive, heavy hand-reworking and sometimes extensive welding of OEM head castings. And for most folks, doing something like this was also next to impossible. It sometimes took more than one skilled head porter to get the job done. And those guys didn’t come cheaply and they sure weren’t common. Most were so busy, no matter who you were, you had to get in line. That isn’t so much the case today, at least for the common Joe. All you have to do is you is key in what you want in an internet search; pick up the phone and order the heads of choice. Better still, a large chunk of the racing technology can be directly incorporated into something like a street-strip car.
That surely sounds simple. But hold for one minute. If you survey the cylinder head market, you’ll quickly discover it’s jam-packed with capable cylinder heads. The choices available out there are almost infinite. And instead of being easy, the selection process can become muddy to say the least. Equally important, just because there are inexpensive high flowing ported heads out there, it doesn’t mean all work well. So what’s right for a little guy?
That’s a wide open question, but the reality is if you’re in the market and want to buy a set of heads, then the first to do is to identify the mission. Companies such as Brodix (https://brodix.com) offer cylinder heads for everything from a take-no-prisoners power adder match race car to a daily driver and everything in between. On the cylinder head front, Brodix offers cylinder heads for Big Block Chevys, LS Chevys, Small Block Chevys, 90-degree V6 Chevys, Small Block Fords, Small Block Mopars, Big Block Mopars along with spec race series jobs.
Take the case of what is unquestionably the most popular engine in drag racing today: The big block Chevy. There are hundreds of heads available for the venerable rat motor. And the folks from Brodix offer a huge number themselves: They range from itsy-bitsy 270 (or so) cc oval port direct replacement jobs (Race Rite series) to monster 515 cc spread port heads capable of feeding 800 + cubic inch engine combinations. Brodix even offers two different rolled over (deck) conventional port location heads that dominate the Texas Pro Stock class. And just to make it more interesting, the majority of spread port BBC heads sprang from Brodix’ early involvement with Pontiac Pro Stock development in the Eighties. It’s easy to see that fancy is easy today. But for the little guy (this writer included) there’s trouble brewing. That’s because there’s so much choice, it’s easy to make a mistake on head selection. Allow me to explain:
If you have a pretty good combination and you want to update it with new heads, there are some real hard considerations. Take the 540-inch BBC I’m slowly assembling. I required a set of heads that moved sufficient air to feed it at 7500 or so RPM. They had to be conventional in layout (no spread ports) and the engine combination had to be somewhat streetable (not a daily driver though). At first, I wanted to keep the headers I had. That meant the exhaust port had to be in a location that was close to stock.
The big elephant in the room was most likely header fit. You see, a very (very) large percentage of heads sold today take advantage of raised exhaust ports. They’re great news because they can easily be made to flow very well. Some manufacturers even make raised exhaust ports standard across the board. That’s where the trouble can really percolate. You see, raising an exhaust port by a mere ¼-inch or so can pretty much ruin header fit in plenty of cars, no matter what some folks tell you. To make headers fit in some applications, you’ll either have to heavily squash the tubes or move them (not fun). Or buy new headers. That presents another problem. There are few “shelf” headers available to fit raised ports. And how could there be? The manufacturers would have to offer headers for myriad raised port dimensions (just think of the combinations for just 0.250 taller, 0.300 taller, 0.500-inch and 0.600-inch taller-than-stock ports times the number of potential chassis combinations). That means you’re often stuck with custom headers.
Brodix had me covered here. Their Race Rite lineup places the exhaust port in the stock location. The intake port choices are more diverse. Race Rites for big blocks can be had in a huge array of configurations, ranging from the previously mentioned 270-cc oval port jobs all the way up to 355 cc examples based upon Brodix’s own BB-2 Xtra series. They also offer Race Rite heads in two examples that are rolled over. That means the valve angle measures 24-degrees instead of the stock 26-degrees. One of those heads has intake ports based upon the Brodix BB-3 Xtra O. It only measures 298 cc’s in intake volume, but it flows over 390 CFM. The other is a much larger 345 cc head with the intake port based upon the Brodix BB-3 Xtra 345. It flows well over 415 CFM right out of the box.
That’s certainly not the end of it (far from it in fact). Next issue we’ll look at how those Race Rite BB-3 XTRA 345’s compare to a raised port example. The numbers generated by the folks at Brodix are considerable. Watch for it.