Chuck Lofgren, Lofgren Auto Specialties
"We're going to go with the Mopar cast-iron original cylinder heads. They are very good heads. We just find we are getting much better low-lift flow out of them than the aluminum heads. The question is on the intake valves. We are looking at how nail-head-style valves react with the ports. They look good at the 3-4-.500-inch lift numbers, but we need to look at the blow-through situation with that angle of valve, and we've got to get it on the dyno. The problem is, we got our block so late that we are limited in time to test valves. In the past, it's just like any other engine, the more intake flow you seem to throw at it, the better. You have to be careful on the exhaust side with the blow-through at low-lift flow.
"Since cost is a factor, we are going to go with the stock rockers, and I am trying to keep the cost down. One thing with the valvetrain I ran into is, the lifter bores of the block needed correction, and this adds to the cost. With the iron head, I think it may be an eye opener for some of the guys in this challenge. With porting and the right combination, it will be a strong engine."
David Burns, Mid America Racing Engines
"We're looking at the Indy cylinder head, going with the CNC ported heads as delivered by Indy. The port layout of the Indy heads are a distinct advantage. We are also going to use Indy components for the valvetrain, as well as their valve sizes. I think these heads with their ports are the best choice."
Larry Shepard, Hemi's Only
"I'm going to use the Mopar Performance iron head. I had a friend in that business port and polish them; his name is Mark Lepole, and he is excellent at that. Basically, we just kissed the surface about .010 inch and did a normal valve job. I'm going to use the Landy rockers; there is nothing special there, just normal shaft pedestals and normal shafts.
"I went with the iron heads because of the 93 octane; I wanted the thermal efficiency. Since we can't put 12:1 compression in it because we are not running race gas, I wanted the thermal efficiency that iron gives; aluminum steals a lot of temperature out of the chambers. Those are my thoughts, maybe I'll be wrong, or maybe I'll have more horsepower than anyone else, but that's what I'm thinking. Everyone has their own views on making torque and horsepower, but with the fuel they give us, and, naturally, the compression levels we're stuck with because of that fuel, this is my choice. Basically it's a stock iron head with the modifications I've talked about."
Jeff Dickey, J.D. Engine and Machine"I'm going to use the Stage V heads. I had Total Flow go through them for me, and the main thing we focused on was port velocity. The idea was not to let the port volume get out of hand, but building a lot of velocity and a lot of swirl. That in turn could make all of this work. I'm not going crazy with compression ratio. I'm building this thing at 11:1, I could have gone 12:1, but I'm building it at 11:1 because it is more streetable in the post-dyno testing. The Stage V heads were used because the normal guy will grab the Indy head and build the cookie-cutter 500-inch Hemi. I'm a little more unorthodox and cutting edge on this deal. The high-velocity cylinder head will work. The valve sizes will be the normal 2.25/1.94 inch, since I don't feel there is a whole lot in valve sizes with such a small bore ... I don't think there is anything there. I'm using Indy rockers and the rocker stands from Mancini."
2005 Royal Purple Engine Challenge Participants
J.D. Engine and Machine
900 Spencer Ave.
Columbia, MO 65203
4131 South Main St.
Akron, OH 44319
6928 Clinton Hwy.
Knoxville, TN 37921
Indy Cylinder Head
8621 Southeastern Ave.
Indianapolis, IN 46239