The Hooker Super Comp headers would make this engine a drop into any early Mopar A-body. I
The ultra-smooth crank journal finish allowed Brett to use an out-of-the-box set of Clevite H bearings without any concern for wear. When asked about the oil pressure he ran to maintain those bearings, he says, "Man, I had way too much. It was like 85 psi. Chryslers are notoriously bad oilers, and I just wasn't comfortable running 40 psi. I know it can be done, but this is my first year [in the EMC] and I just wanted to keep it safe." The 5W-30 Royal Purple didn't let Miller down, and the bearings looked perfect after the dyno runs.
A source of pride and contention among the Chrysler fans is the whole camshaft area. Mo-Powers use a big 0.904-inch lifter that lets the cam grinder get super aggressive with lobe designs. Brett used lifter bushings installed with a BHJ Lifter-True fixture to make sure they were all correctly located, and then had COMP Cams whip up a custom solid flat-tappet cam with their "Mopar only" MM cam lobes for those honkin' lifters. One of the tricks of the trade that Miller keyed us in on was that you can build cylinder pressure and fake the engine into thinking it has more compression than it really does by closing the intake valve early in the camshaft cycle. He used an externally adjustable Weber belt drive to make quick changes on the dyno. Starting with a pretty tight 106-degree lobe separation to allow the exhaust to help pull in the intake charge, he set up the intake centerline at 102 degrees. "I remember this vividly. That's why we put the belt drive on, so it'd be easy to jack the cam around. It made pretty good power, so I said, 'hey, let's see if we can pick up the bottom end. I want to advance this cam.' I had it in at 102, then I advanced it to 100 and it killed it, which shocked me. I said, 'Let's go 2 more degrees and see what it does.' We started another pull and it did so bad we just aborted it." It turned out that the initial 102-degree intake centerline was the sweet spot. "I think the reason advancing it more didn't help me was because it just built too much cylinder pressure [for the pump gas]."
Factory blocks like Brett's used a cam tunnel that is significantly raised compared to the Brand X guys, letting cranks with mucho-mondo arms to swing around without running the connecting rods right into the cam. That is a good thing. The curse of that raised-cam tunnel design is the odd 59-degree angle that the lifters sit at. While most V-8 engines use a lifter angle around 45 degrees (makes sense right?), the engine designers must have been out watching the Ramchargers running down the strip the day they were supposed to design the lifter placement, leaving the chore to some intern. The problem here is that it sets up a compound angle with the pushrod creating a point of friction and wear, costing power and longevity. Thankfully, Brett's 345 survived the rigors of the Challenge without any issues.
In '68 through '70, the 340s were blessed with a 10.5:1 compression ratio, same as in the Challenge. JE provided the domed pistons that would support that compression ratio. Unlike the aluminum ashtrays of yesteryear, these technologically advanced pistons were built with the precision of a Swiss watch with tight ring grooves and a full round skirt to reduce piston rock and combustion pressure loss. JE also supplied the narrow, metric rings for Brett's endeavor. The low-tension rings, along with the ESP Armor crank treatment, allowed the fully assembled short-block to rotate with a mere 16 lb-ft of force. Basically, you can grab the crank snout with your bare hand and turn the engine over!
Miller didn't want to fart around with an el cheapo ignition system and risk hurting his e
Patrick James of Pro Systems tells us that one of the best tuning aids he has when buildin
Team members Vic Bloomer, Brett Miller, and Tina Miller stand behind their baby. They had