August Cederstrand, Speed-O-Motive
"I figured most guys will be using either the Indy heads or modified Mopar Performance heads, either the iron or aluminum heads. We wanted to take a different approach and decided upon the Stage V street replacement heads. This was kind of interesting to us, since they are a local west coast manufacturer, and we like the angle of this unique product. We are taking a set of these heads for hand porting and polishing here in-house rather than just using the standard off-the-shelf CNC ported heads, though there is nothing wrong with that. We have the expertise to do the ports our way, and I think it will be an advantage. We are going to go with Comp's beehive springs to reduce the weight and internal harmonics of the valvetrain in the rpm range of the competition from 3,000-7,000 rpm.
"I'm going to use 2.250-inch valves on the intake and 1.900-inch valves on the exhaust. That's smaller on the exhaust than the stock Hemi, but we're doing something a little different here, and, in fact, I think this valve size will work better in the overall combination. This isn't a particularly big head, but is sized right for this contest, and, of course, I'm using the Stage V rockers. in terms of flow numbers, once we have them ported, we're looking to see numbers in the range of what can be seen with the Indy 426-1 heads. We're also going to go with a full-coating package (thermal barrier), including the chambers, valves, and so on, to keep the heat transfer and detonation in check, and we do all that in-house. This should be a combination that will deliver a strong showing."
Ken Lazzeri, Indy Cylinder Heads
"For an engine of the specs required under the rules of the Hemi Challenge, we need to go with the smallest units we have: the Indy 426-1 CNC 285. These heads have a 285cc intake runner, 123cc exhaust runners, 166cc chamber, and 2.25/1.94-inch valves. We're going to fit them with Comp's 928 springs, and Comp's 10-degree locks and titanium retainers. Even with our smaller heads, we have way more capacity than what the rpm range of the competition dictates, and anything bigger will be way out of its range. These heads can take you all the way to 8,200 rpm, but even at the rpm range we're limited to, it will make all kinds of power.
"One of the keys with the Hemi is valvetrain control, especially with the flat tappet. You need the spring load to make the rpm, and we would normally use a roller with the Hemi. We're going to use our full valvetrain. We're going to build this with exactly the parts we sell, though we've never sold one with a solid cam instead of a roller in eleven years. It's just not a real sensible combo with the solid flat tappet when looking for reliable power, but we have to build it by the rules. It's not exactly the combination I would recommend to the customer, just because of the built-in compromises, but it will be a very strong running Hemi, I'll see to that."
Ken Hensley, Hensley Performance"We're in a real tizzy right now just looking to make the competition, since we are unexpectedly short-handed. We have major work with our race customers, and we are just jammed up something fierce with keeping our racers running. We are going to go with the Indy heads, since I know they make power. We were going to go with whatever we could under the rules to prep them for the competition, and we have the expertise to do full race porting. It is just a very time-consuming process. For this type of motor, we are not going to go crazy with port size, because if you do, its going to have to have some really high-rpm to pull that power out of there. Our plan was not to get the ports to where you can stick your leg in them."