Priding themselves on being engine builders as well as manufacturers, the Indy team employed some rather unique tricks to their PN 440-SR CNC cylinder heads. Instead of simply bolting on an off-the-shelf head, they used their CNC castings as a foundation for a trick set of heads. Rather than using the standard length valves, Indy consulted with Randy Longstreet of Manley Performance Products who recommended a set of titanium 2.300 inch intake, and 1.76 inch exhaust valves with longer than standard stems. While there are several advantages to longer valves, the main advantage is that a more aggressive, higher lift camshaft can be utilized without worrying about valvespring coil bind, or retainer to guide clearance.

Unfortunately, longer valve stems play havoc on the valvetrain geometry, requiring the rocker arms to be relocated. Since our rules prohibited welding on the head, Indy got creative and manufactured specially offset bushings and shims to move the rocker studs away from valves. Larry Tores of T&D Machine Products helped to calculate valvetrain geometry, recommending T&D PN 8216 rocker arms with 1.7 intake and exhaust ratios. The Indy crew also used a somewhat unconventional method to "unshroud" the intake valves, but you'll have to ask them about that trick because we're not telling all their secrets.

To top off their long block, Indy made the logical choice of their PN 440-15 tunnel-ram intake manifold. Knowing that a tunnel-ram produces more peak power, and since our contest factors peak torque and horsepower instead of averages, using a tunnel ram and dual four-barrel induction just made sense. To mix the fuel and air, and since total induction volume was limited to 1,350 cfm, Indy chose a pair of Barry Grant 675-cfm Race Demon carburetors. Topped with Indy PN 440-7PC cast aluminum valve covers and ignited by an MSD PN 8546 Pro-Billet distributor, this combination screamed to 758 hp and 601.6 lb/ft of torque to win this year's Engine Challenge. We congratulate Indy on their win and thank them for sharing what it took to put together this winning combination.

2008 Participants
Indy Cylinder Head
Indianapolis, IN 46239
317/862-3724
indyheads.com

Schurbon Engine and Machine
Maquoketa, IA 52060
563/652-3100

JMS Racing Engines
El Monte, CA 91732
626/579-4567
jmsracing.com

JD Engine and Machine
Columbia, MO 65203
573/445-4550

Chenoweth Speed and Machine
Morton, IL 61550
309/266-8084
chenowethspeedandmachine.com

Cederstrand Racing Engines
Brea, CA 92821
714/653-4523
Cederstrandracingengines.com

Promax
Indianapolis, IN 46222
317/241-3432
sales@promaxcarbs.com

Editor's Note: If you want to hear the Indy Cylinder Head engine run, go to our web site, www.moparmusclemagazine.com, and check out the video section. Don't forget to turn your volume up.