Jack Mcinnis Of Dart Machinery Discusses The Latest Innovations In Blocks And Heads
At the core of every high-caliber race engine are mega-cfm heads that make the power and a rugged block that holds it all together. These are arguably the two most critical components in terms of power and reliability, and Dart has been among the upper echelon of cylinder-head and engine-block manufacturers for nearly three decades. Founded by Pro Stock legend Richard Maskin, Dart's product line incorporates genuine race technology into off-the-shelf components available to the average enthusiast. With a competitive motivation to build championship-winning NHRA Pro Stock engines in the '70s, some of Maskin's early innovations included raised intake runners, offset pushrods, and sheetmetal intake manifolds. He eventually learned to build cylinder heads from scratch, and his aluminum Hemi heads helped power the first Funny Car into the 4-second quarter and the first Top Fuel dragster to break the 300-mph barrier.
Over the years, these racing exploits translated into the quality aftermarket components that have earned Dart one of the most respected reputations in the industry. With a catalog that encompasses big-blocks, Mouse motors, and LS1s, the company's collective minds have a wealth of information pertinent to Bow Tie fans. We chatted with Dart's Jack McInnis on topics ranging from metallurgy to engine coatings, cylinder head design to manufacturing, and here's what we learned.
It's best to get your advice from the manufacturers or an experienced engine builder, rather than someone you've never met who is posting on an Internet forum.
Raw Stock
When examining a finished cylinder head or block, the raw material used in the final product isn't usually a big concern to most hot rodders. However, the quality of the raw stock is critical to engine reliability. "All our raw materials come from U.S. suppliers, and the quality of the alloys has a great effect of the strength and durability of the finished product," explains Jack. "For example, we use only virgin C355-T6 alloy for our aluminum blocks and heads. The virgin material is highly consistent, whereas aluminum that contains recycled or remelted materials tends to have areas which are harder or softer in the finished piece, as well as inclusions of sand and other foreign material."