The teams were happy with their performances which would have qualified them at the NHRA Winternationals, but there were some issues with the R&D Hemi engines that kept the teams from using them to qualify at Pomona.

In January of this year, a source close to the team told DRO, “We’re really happy with the engine but we’ve got a few problems with the cylinder heads. After we ported the intake and exhaust runners so that the heads would flow enough air to make horsepower, cracks developed in the walls and when we made a pass we would get a little water in the oil. It’s nothing serious, but it's something we need to fix.”

Another problem for the new Hemi was the original piston design. According to Larry Morgan, who is developing the engine for Mopar along with David Nickens, the original piston design for the new Hemi was based on the pistons used in nitro burning Hemis. Those pistons are designed to be “bulletproof” and as a result are about 100 grams heavier than the teams would like them to be. Heavier pistons mean more rotating weight which means that it takes more time for the engine to get to the rpm band where the engine makes optimum horsepower and torque.

Since the first new Hemis were built, Mopar has cast and delivered new cylinder heads with re-designed combustion chambers and more material in the port and runner areas. The first batch of lightweight pistons have also been delivered to David Nickens. The factory-backed David Nickens team has opted to run the rest of the season with the new Hemi since it is reported that his new Hemi engines made more power than the wedge engines the team started the season with.

Until Morgan gets all of the re-designed parts for the Hemi, including new pistons and heads, look for Morgan to continue to run his Chrysler Wedge motors which powered his Avenger to a 6.86 at over 200mph in testing.

“Right now the Hemi I’m dynoing is making at least 15 less horsepower in the high rpm range than my wedge motor. In Pro Stock racing, that can mean the difference between qualifying and not,” said Morgan. “I am really impressed with the horsepower that David Nickens is making with his Hemi and the fact that Darrell (Alderman) was able to put the car in the show at Gainesville.”

The team plans to have the Hemi in the car and race with it full time after the first NHRA Houston race and then ready another Hemi for John Nobile.

“I’m sure that when we get all the new parts for our engine program our Hemi will make as much or more power than any other engine,” Morgan said. “Both myself and Billy (crew chief Billy Wagner) are looking forward to racing with a Hemi and taking it to the NHRA winners circle.”

Inside Mopar’s new “Hemi”

This photo shows the changes in the first production run of cylinder heads compared to the second run. The combustion chamber on the left is the original design and the new chamber is at the right.

No engine in recent drag racing history has been more shrouded in mystery since the Chevy “porcupine” big block motor of the early sixties. Early press reports by Mopar expert Al Kirschenbaum indicated that the new Mopar “Hemi” really wouldn’t have a true Hemispherical combustion chamber and the man was right, absolutely!

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