PRI 2019: Raised-Cam Hemi Block From AJPE Redefines The Platform

When it comes to Pro-Modified level engine hardware, there are only a few names that appear at the top of the qualifying sheets on a regular basis. One of those names is Alan Johnson Performance Engineering — or AJPE for short. Widely known for the huge-power Hemi-based engines, AJPE has taken the next step to further improve the platform.

“We started a little over a year ago with the concept of building an engine with a raised cam so we could accomplish a number of things,” says Alan Johnson. “The Chrysler Hemi has always not had the greatest valvetrain. We sell a lot of Wedge engines that have a really good valvetrain, and we sell a lot of Hemi engines that have not quite as good of a valvetrain”

Looking at both platforms, AJPE wondered if they could mimic the Wedge engine’s attributes, but in a Hemi platform. “We wanted to combine them and take development from the valvetrain of the Wedge engine and move it over to the Hemi engine, to try and create some sort of a hybrid engine that would have the best of both worlds,” explained Johnson.

In doing so, AJPE has made some radical changes to it’s popular Hemi block. “We’ve raised the camshaft up, and built a whole new valvetrain assembly for it. We were able to shorten our pushrods and create a straighter pushrod. We created a valvetrain that we know is going to help the engine run at a higher RPM and develop more power up there,” Johnson says.

However, it wasn’t just the camshaft location that AJPE addressed. In fact, it was really the whole camshaft system that has been revamped. “We were able to add a 70mm camshaft to it, along with another bearing support, so there’s a sixth bearing for the camshaft.” Relays Johnson.

“That spread in the forward part of the camshaft had a tendency to create harmonics, so by adding that extra bearing there, and going to a 70mm camshaft core, we’ve eliminated that harmonic. The result is an engine that has set speed records in Pro Mod twice this year, at over 260 mph. We are extremely pleased with the outcome.”

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About the author

Greg Acosta

Greg has spent fifteen years and counting in automotive publishing, with most of his work having a very technical focus. Always interested in how things work, he enjoys sharing his passion for automotive technology with the reader.
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