At CVMS, we offer professional porting services. We don't have a "CNC" machine, we have an "LD". David "LD" Wilcox, jr. has been porting heads for over 30 years. He is also the man behind the wheel of what is currently the quickest Pontiac-powered car on the planet. Oh, and he ported the heads that are on it!
We read on various forums and hear from folks all the time, about their CNC-ported heads. It's funny, but the perception seems to be CNC porting is superior to "hand" porting. Perhaps CNC porting IS better than some peoples' hand porting. Professionals are not among those. A good cylinder head man can maintain consistency in both cross-section and finish quality. In truth, a "CNC'd" port is only as good as the person that ported it for digitizing.
More importantly, a CNC machine does not learn. A professional porter does! We've read where it's okay as long as they start out with a "perfect" port. Well, since humans design the ports AND the machines, perfection is not part of the equasion. Any statement to the contrary simply isn't realistic.
Our cylinder heads are designed individually for the specific application. Each set is different than the rest, just as each car and each customer are different. In this day and age, it's fashionable to use "cookie cutter" parts and buzz words for bragging rights. We at CVMS are a bit more discerning and our customers are more demanding. If you buy the heads from the CNC people, your engine will perform the same as any other engine using the same source for heads.
We have also had our customers told by other shops there are certain limits to what is possible for a given casting. While that's true (limitations in physical space), in one case it was said "You can't get more than 270 CFM from a 4X {Pontiac} head no matter how hard you try!" In this particular case, we were building a new F.A.S.T. (Factory Appearance, Stock Tire) Class engine. CVMS had built the previous engine for the customer. The heads for the old build were already at 285, and they were three years old. When asked if he (the customer) was looking for a bargain or an "edge", he replied he was looking for the edge. The new engine sports 4X heads that flow 300 CFM at .600" lift, and all within the confines of the stock location for ports and pushrods. It would have been better worded "WE (the other shop) can't get more than 270 CFM..."
The sky really IS the limit. With enough time and effort, old barriers (perceived more than real) fall by the way. We're getting more flow and more power (the two, while related, are not necessarily the same) with every set of heads we build. We can provide flow numbers, as we DO have a Custom Flow 400 pitot-tube style flow bench. However, we have learned the numbers aren't always the only measure of a good set of heads. We've also learned, low and mid-lift flow are far more critical to overall power production than "peak" numbers. Instead of flow numbers, we offer track numbers. Our customers' cars are among the quickest in their respective classes than any other out there, especially the Pontiacs. By applying modern techniques to the old Injun, we have brought the Pontiac to the next level. Our Chevy engines don't run too bad, either!
We understand port work is labor-intensive, and therefore rather expensive. One will ALWAYS get the fair amount of time charged, devoted to their cylinder heads. We have some "packages" that can save a bit of money, as they're the more commonly requested levels. We offer all levels of cylinder head work, including repairs of damaged race heads from other shops. Aluminum heads are rather easily repaired in most cases. Iron heads take a bit more effort. We install screw-in studs and guideplates in stock small blocks all the way to 480 CFM "Tigers" for a blown-alcohol Pontiac. Imports and exotics are also welcome. Ask about our "swirl/tumble" combination for 4-valve heads.
