Mopar Dodge And Plymouth Hemi Engines - High Horse Hemis

Those of you who have been following our engine challenge know that horsepower and torque were only two aspects of each engine that were rated in our challenge. The cost of the parts in each engine was also factored to achieve a composite score for each engine. Our competition was very close with only decimals separating the competitors, a clear indication of the time each builder spent picking the proper parts to make cost effective horsepower. this month's two feature engines placed third and fourth in our challenge, and we must say we were impressed with the raw power of these two entries. Jeff Dickey of J.D. Engine and Machine made top power with his dual Dominator-fed Hemi, posting a very respectable and contest-leading 728.2 hp. August Cedarstrand of Speed-O-Motive wasn't far behind, leading the single carburetor entries with 722.6 hp. This month, we'll go inside both motors and look at what makes these combinations perform.

J.D. Engine And Machine; Columbia, MO
Jeff Dickey of J.D. Engine and Machine was very clear about his goal in our engine challenge. His engine would make so much horsepower and torque that no one could compete with his entry no matter how economically they built their engine. Had it not been for a couple of weak valvesprings causing valve float above 6,700 rpm, we're pretty sure he would have achieved that goal. Jeff is no stranger to powerful engines, having built everything from street friendly small-blocks to Pro Stock mountain motors. Jeff and his crew are avid racers and campaign a 10.5-inch-tire "street" car that has been upwards of 200 mph in the quarter-mile. His latest endeavor involves applying what he's learned racing the 10.5-inch car to a true NHRA legal Pro-Modified ride, which should be complete and ready to race this season. Jeff's shop in Columbia, Missouri, is a full-service machine shop and can build as much power as your budget, or your car, can handle. His keys to being competitive in the engine challenge were power, power, and more power. Knowing that cost would be factored, however, Jeff did use economical parts where he could, saving a substantial portion of his budget for his tunnel-ram and dual Dominator induction. Jeff's theory was you can't make big power unless you move air and fuel through the engine. Even with valve float greatly reducing power above 6,700 rpm, this engine posted the highest horsepower in the competition.

When it came to the short-block, Jeff knew that since his engine would need to survive six pulls at a painfully slow acceleration rate, durability would be the key to surviving this contest. After checking his Mopar Performance Siamese block, he discovered the lifter bores were not located precisely enough for his exacting standards. Realizing this would effect valve timing, he chose to bore and bush the lifter bores to their proper locations. Additionally, the block was decked so the piston was at the top of the bore, and the main journals were line honed for accuracy. He also modified the block to help the oil return to the pan, picking up extra ponies through reduced crankcase windage. Inside his block, Jeff used an Eagle 4.150-inch stroke crankshaft along with Eagle 6.76 length steel H-beam rods spinning on Clevite bearings. The crankshaft's indexing was checked and was micro-polished prior to installation. Diamond custom pistons round out the rotating assembly, which is kept oiled by a Melling pump and Milodon oil pan and windage tray. An ATI Super Dampener was utilized to keep harmonics to a minimum, as well as to make this engine legal with racing sanctioning bodies.