Yet another piece of this super-mamma-jamma block is the 50mm cam core. Those of the Pentastar persuasion will no doubt know that oiling to the top end is done with the help of the factory camshaft. Oil is fed across a groove or holes in the No. 2 and 4 cam journal then through passages in the block up to the factory shaft rockers up top. This race block with 50mm roller cam bearings is designed to oil the top end through the lifters and up the pushrods so it does not have the trademark cam journal grooves or holes. The thing about special cam cores like this is that they can be really expensive. Miller had a few sitting in his pile of goodies, which he was able to send to Predator Cams to grind for this 412. The other thing about cam cores is that when regrinding them, you can only grind off so much to move the duration and lobe centers around. “I tried to get the duration as short as I could with the lobes I had available. I had a bunch of 50mm cams from that Truck stuff, but I could only shrink them so much and move the lobe separation a degree or two. With that, the cores kind of dictated what I could do with the cams.” That said, the specialists at Predator were able to whittle up a pair of lobes with 255 degrees at .050-inch lift on the intake and 259 degrees on the exhaust. Coupled with T&D 1.8 rocker arms, the valves lofted open to a peak .781-inch lift. Regarding the rocker arms for W8 heads, and any of the W series racing heads, they were very specific about what rocker arms they used. The W7s were more notorious for multiple rocker bolt patterns and locations, but since these were designed for NASCAR use and those old boys in North Carolina were known for moving things around here and there, you might not always get something that works when buying a set of heads and rockers from two different people. Lesson is, if you plan on buying a set of used NASCAR heads, get the matching rockers. This wasn’t Miller’s first rodeo, so he cut that headache off at the pass when he bought the donor motor complete.
To make all the valvetrain components do their dance, the cam had to be coupled to the crank in some manner. More specifically, a Jesel beltdrive joined the bumpstick to a reground crankshaft. Not a cheesy factory regrind, of course. This forged LA Enterprises piece was sent to the delicate hands of Adney Brown at Performance Crankshaft. The specialist took the forging in and offset ground it to pick up a quarter inch of stroke in hopes of increasing the torque in the 3,500-7,500 rpm operating range of the EMC.
Looking to save a little money, Miller found a set of bejeweled 6-inch Carillo rods on eBay for a quarter of their original cost. It helps to shop around. On the top end of the rods were a set of pistons that Miller didn’t want to skimp on. He called his buddy at Wiseco to hook him up with a low-drag skirt design that would work with the 15-degree heads and produce a killer 14.5:1 compression ratio. It wasn’t just the pistons that were maximum effort. The rings were super-skinny low-friction parts common to the top NASCAR ranks. Talking with another pal at JE, he asked what the desired hone job would be. “I’ve read up and people say you can get cylinder walls too smooth. Well, the cylinder walls in that motor were like glass. It wouldn’t even grab lint off a paper towel.” It didn’t hurt that the gentleman honing his block was a guy honing top NASCAR and Pro Stock blocks all day long.
Once Miller had it all figured out how to convert the reciprocating energy of combustion into rotating energy transmitted through his crankshaft, there was the matter of controlling an unwanted byproduct of that rotational motion: windage. Charlie’s Oil Pans has been a major player in building race pans and oiling systems, especially for those inclined toward Chrysler products. Miller called Charlie up and described the combination he was putting together for the EMC. As mentioned before, the block was designed for a dry-sump oiling system but the rules for competition dictated using a wet sump. Charlie whipped up an aluminum pan and pickup that would fit, but it was up to Miller to modify the rear main cap to hold an oil pump. Dry-sump blocks have a solid rear main cap, so he machined it to mount a Melling pump on it and make it all work.
After all the innards were carefully wrenched together, Miller went to work trying to get the most out of the powerplant. That meant heading to his buddy’s dyno at Rider Race Engines and screwing it to the pump. Usually, there are some rounds of ignition timing and carb jetting going back and forth and this was no different, except the efforts weren’t giving the results he knew were supposed to be there. It was time to delve a little deeper into the bag of tricks and move the cam around. He found that with the cam’s 105-degree lobe separation, it liked to be advanced all the way to 97 degrees to get the best average torque and horsepower score across a range of 3,500 to 7,500 rpm. Still, it was lacking down low. “It’s the weirdest stuff that builds score. We put a reducer on the collector from 3.5 inches down to 3 inches, and it picked up 50 lb-ft of torque at the hit.” That was the magic combination that made the fat lady sing. The old girl belted out a whopping 749.4 hp. While he could have spent another day fussing with it to pick up that extra .6 hp, where we hang out that is just one bad 750-horse small-block.