While we were gone, the Vrbancic Brothers decided to get a leg up and throw a cylinder head and rocker assembly on to make sure everything was...headed in the right direction (yes, I was trying to be funny).While we were gone, the Vrbancic Brothers decided to get a leg up and throw a cylinder hea Last month, we took a look at the assembly of the Vrbancic Brothers' 414ci ATI blown short-block. To successfully build an engine that will consistently withstand the added internal pressures that come with supercharging and racing, we need to not only think about the strength of the parts but also the design and construction that has been painstakingly built in to these parts ensuring efficiency and longevity. This compiling of certain parts comes from years of dyno pulls and the right (and wrong) results on the track. The Vrbancic Brothers take all of these experiences very seriously. With respect to that statement, we are going to spend a little time on the Brodix aluminum heads and the work that went into preparing them for this engine-and why. Remember, when adding a supercharger (or the like) to an engine, you are simply adding a great deal more air and fuel, causing an increase in internal pressure. With that in mind, the first thing to think about is creating an unrestricted, consistent flow through the heads. Jennings Racing Heads (formerly Air Flow Dynamics of Upland, California) did a superb job porting, polishing, and performing a valve job. That's just the start. These heads go far beyond any normal port and polish. Even the T&D rocker setup is about as trick as you can get these days. This setup utilizes a one-piece steel base that will keep the rockers in place with no worry of pulling studs. Better yet, take a closer look through the photos, and we will attempt to explain these parts as you see them. Oh yeah, just to keep your saliva flowing (or just to keep you reading), after all was said and done, this small-block pumped out over a 1,000 hp with almost 800 lb-ft of torque. If that doesn't pique your interest, skip to the next story. Material was also taken away and added to reshape and clearance the pushrod passageways-more on this as you read further.Material was also taken away and added to reshape and clearance the pushrod passageways-mo With the Manley valves slid into place, it was determined that a .015 valvespring shim would be necessary for the correct installation height.With the Manley valves slid into place, it was determined that a .015 valvespring shim wou The right combination of Manley Severe Duty valves, Manley NexTek Series double valvesprings, and COMP Cams valve seals are all old favorites, because they are strong, reliable, and work.The right combination of Manley Severe Duty valves, Manley NexTek Series double valvesprin Luckily, the Brothers decided to wait to assemble the other head so we could photograph it and learn a little about flow. It may be hard to see in this photo, but even the intake valveguide stems have been shaped using existing material along with some that was added. The stems have been shaped much like the wing of an airplane, with a peak facing into the direction of flow to allow the fuel and air mixture to smoothly flow around the stem with the least amount of restriction. Left alone, the flow can get caught behind the stem, thereby reducing the efficiency and speed as the mixture enters the cylinder.Luckily, the Brothers decided to wait to assemble the other head so we could photograph it This is the same intake port as above. From this angle we can see even more reshaping and can understand the resulting increase in flow efficiency when comparing the bottom of the intake guide to that of the stock exhaust valveguide.This is the same intake port as above. From this angle we can see even more reshaping and Now that the head is nearing completion, Bob prepares the COMP Cams Hi-Tech roller lifters by carefully linking them together with COMP's patented link system that utilizes the convenience of a removable link and the safety of a captured link.Now that the head is nearing completion, Bob prepares the COMP Cams Hi-Tech roller lifters 1 | 2 | 3 | » | View Full Article By Jason Walker Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
