By Alfie Bilk:
If you were seeking a guidebook on how not to carve out a career in motor sport, Greg Brown’s story might be a good starting place.
Following two years of studying numerous concepts and with a prototype partially complete, he undertook the daunting task of pioneering production Hemi cylinder heads for the small-block Ford engine in a scant period of just under four and a half months.
The processes for developing the rare Hemi included complex scanning to gather CAD data, mobilizing a casting company to create the tangible form and developing a CNC program that would sculpt its final shape. Then, a head was urgently dispatched to Jesel to develop crucial rocker development.
With an intuitive grasp of the technical and an eye for future opportunities, what had shaped Brown’s decision? “If I failed to display it at the 2016 PRI exhibition in Indianapolis, I could potentially squander a year,” he said. The performance-minded public, particularly those based in the Northeast is large and active and languishing for a further 52 weeks in obscurity was obviously not an attractive proposition. Even more astounding, word of the unique cylinder head would be released without any convincing proof of a single dyno test. There was simply no time.
When the inaugural dynamometer test of the new heads, which were attached to a 427ci World Products block, was eventually undertaken in January 2017, the results were astounding: 604hp and 601lb-ft torque. Astounding because the initial set up was meant to deliver 10.5:1 compression ratio. However, final valve changes were made, which entailed moving the intake valve seats to slightly higher territory in the combustion chamber. As a result, the original 62cc chambers had now gained 6 or 7 cubic centimeters of volume and valuable compression properties were reduced to a meager 9.8:1.
Flow details supplied by Superflow flow bench in conjunction with a 4.125in bore
LIFT INTAKE. EXHAUST
Furthermore, an out-of-the-box Edelbrock Victor Jr. intake manifold had been employed, its ports much too small when attached to the new Hemi heads. Why? “I wanted to ascertain the power output of un-ported heads when combined with an untouched intake, said Brown. A third factor that influenced the dyno sheets was the humble camshaft with duration values of 242 intake / 248 exhaust. “Getting it to 500hp is easy,” declares Brown, but generating over 600hp with low compression, un-ported heads, untouched intake and a modest camshaft is a triumph—I’m very pleased with its maiden performance”
So, what’s next? “Currently, I’m pressing ahead fulfilling orders,” he says. These include the supply of rockers, rocker stands, gaskets, etc. “But I’ve now graduated to offering pistons, rings, distributor extension and cylinder head stud or bolt kits. Also, the first competition version – which I’m working on – will feature a different compression ratio, induction system and camshaft,” says Brown.
Importantly, for this new Hemi concept to realize its full potential, it’s crucial to install it in a race car as soon as possible. This will broaden its appeal and prove its merits. Racing lives on the edge of the competition precipice and an impressive quarter-mile time slip reveals all.
Greg Brown, a 45-year-old who originated from a small town in Vermont and moved with his parents in his teenage years to Atlanta, has now based his fledgling company in the Atlanta suburb of Snellville. Twelve years ago he took employment at Jon Kaase Racing Engines, perhaps reflecting his youthful admiration for the man who has shown such versatility in a long career devoted to the development of racing engines.
Contact Greg at:
Hammerhead Performance Engines
Hammerhead’s new Hemi heads being installed for dyno-testing.