Crossbolted main caps are...
Crossbolted main caps are the quickest way to spot that this is no ordinary RB block, as only Hemi blocks used them. The aftermarket World Products cast block features actual Mopar insignia and a Mopar part number. Strengthening ribs on the sides of the block help keep these castings in one piece well north of the 1,000hp range. An aluminum block is offered for those wanting a “light” 600-plus cube engine.
The single most important characteristic of a cylinder head is to move a large mass of air. The most important features of cylinder head design, which determine the mass of airflow delivered, are the shape and size of the runners, and the most effective shape is a straight shot down with a big valve opening. It comes as no surprise then that the almighty Chrysler Hemi is one of the most effective cylinder head designs when it comes to moving a boatload of air and fuel into an engine.
Corey Short has been a Mopar enthusiast since his pop, Bill, infected him with Hemi fever as a child. Now finally able to afford it, Corey continues to feed his illness by building Hemis for street and race cars alike. “I’ve been a die-hard Chrysler fan my whole life and growing up and reading these magazines, the Hemi was always the prize jewel for me.” Recently Corey, brother Troy, his pop Bill, and his mother Margie polished off this 514-cube Elephant blasting out over 800 horses for the 2011 AMSOIL Engine Masters Challenge under the team name “Triple S,” to represent the Short family. This was definitely not their first shot at the Engine Masters Challenge though. “We’ve been involved in the Engine Masters since 2004 and we’ve been kind of hooked ever since.”
A common modification for...
A common modification for big-block Mopar racers is to use a reverse-cooling scheme. The water pump plate from Indy Cylinder Heads features internal passages that swap the flow around and cool the heads before the block. This lowers the combustion chamber temperatures in the head and reduces the chances of detonation. Plus, it allows the use of a cheap small-block Chevy water pump.
Corey acted as team leader, but as mentioned above, his father has been a Pentastar patriot since the days of the early, baby Hemis. The first-generation Hemi burst on the automotive scene in late 1950 under the 1951 Fire Power name for Chrysler. Among Chrysler’s Fire Power, DeSoto’s Fire Dome, and Dodge’s Red Ram, the early Hemi blocks shared a deep-skirted Y-block design with their later cousins, but there were a number of subtle differences that kept parts interchangeability to a minimum.
The first major difference among the Hemi cousins was their different bore center distances, that is, the distance from one cylinder to the next. Though it may not sound overly important, it is the number-one most important factor in parts interchangeability. With different bore centers, head and cranks were automatically removed from any chance of swapping from one family to another. The Red Ram had the shortest bore-center distance of 4.1875 inches. Considering that there needs to be an absolute minimum distance between the cylinders of .200 inch for a head gasket of any type to seal, and typically about .400 inch for a regular composite gasket to seal with a safety factor acceptable to manufacturers, the bore size limitations of Dodge’s early Hemi become readily apparent. As a result, 241-, 270-, 315- and 325-cube entries were the limit for this baby engine.
An MSD Blaster II coil provided...
An MSD Blaster II coil provided ample spark for the Pro Billet distributor to fire. FireCore provided the spark plug wires that are unique to the Hemi. Unlike some cheapos, their sealed boots are about impossible to pull off. This is critical with Hemis as the plug wires need to come off every time the valve covers are pulled for valve adjustment.
DeSoto’s Fire Dome Hemi sported a slightly longer bore center dimension of 4.3125 inches. Displacement was a modest 276, 291, and 330 ci from 1952 to 1955, but the additional bore distance allowed a jump to 341 and 345 cubes in 1956 and 1957. Those last two years of the Fire Dome also saw the power output climb to the magical 1hp-per-cube range.
Chrysler opened the floodgates to bigger inch and bigger power potential with their 4.5625-inch bore center distance Fire Power Hemi. Compared to the old small-block Chevy’s 4.400 inches, the Fire Power Hemi had some room to grow. The first version emerged at 331 ci, but quickly grew to 354 inches by 1956, and in 1957 a raised-deck version bumped the size to an impressive 392 ci.
In 1958, the early Hemis fell by the wayside for nearly a decade until Chrysler committed to building an engine capable of winning in the growing NASCAR ranks. They pulled out all the stops and created the second-generation Hemi in late 1964, and it was available in street trim by 1966. The Gen II Hemi was a supersized version of its predecessors and was the basis of Corey’s engine. The Gen II shared a deep-skirted Y-block design of the early versions but added cross-bolted main caps and spread the bore centerlines to a healthy 4.800 inches.