The stock-volume, stock-pressure pump was a base-model Melling design that was blueprinted
A common trick with Top Alcohol and Top Fuel pistons is to hard anodize the entire piston, creating a surface that better disburses heat and reduces microwelding to the rings. Simone went ahead and anodized the pieces, but was unsure whether or not it would be possible to add a Teflon coating to the skirt that had been anodized. It turned out to be the perfect surface to add a coating.
Another strength-to-weight issue is brought up with the use of pin buttons to hold the wrist pins in place rather than wire locks or Spiralox. Knowing that he would be beating on the pistons pretty hard, Simone suggested that the buttons replace a good amount of the structural strength given up by boring a hole for the wrist pins. They also provide a shelf for the oil support rail.
As with the piston skirts, the Shotgun crew coated the Scat H-beam rods with an oil-shedding coating. Those rods were floating on a matching 4340 Scat forged crankshaft, internally balanced and captured with King Alecular bearings. The rare four-bolt Boss block is a factory original piece that had never been blown up, and unlike most 385-series blocks, was perfectly happy being bored .080 over. "It's a typical C9AE-E casting and it's a service block. It's not an HP block. It's not one of the blocks that went in the cars, but it is a Boss casting with the priority oiling, the pushrod notches, and four-bolt caps." With priority oiling a standard feature in the Boss blocks, Simone says that any further oil system mods are really unnecessary. "There are no oiling system restrictors in the block. None. The oil pump is a standard-volume, standard-pressure M84D truck pump. That's it. Oil flow is an engine's life blood and if an engine is set up and clearanced properly, at least for a Boss 429, then unless you're at the highest levels of drag racing where you're over 7,500 rpm, you don't need oil system restrictors. You need to feed oil to the parts so they stay happy." They used a windage screen with an open oil pan design combined with crankshaft counterweights that were lathe-turned to keep power robbing windage to a minimum on the stroked big-block.
With a flat-top piston and a shallow chamber, it was easy to get 11.4:1 compression, which
Ouch! How much power did this broken intake valvespring cost? Hard to say for sure, but th
The Boss blocks have the distinction of being the only members of the 385-series engine fa
In the center of all the action is a COMP Cams custom solid-roller cam set up with an 8-2 firing-order swap. Simone claims that he's seen significant power gains from the swap. Simone gave a good amount of thought to camshaft design before ordering his grind. Most wedge heads tend to favor the exhaust a little more than the intake as far as duration goes. With the crossflow design of a hemi head, and a short, straight exhaust port, the hemi typically needs less duration on the exhaust. Making the mistake of installing a cam designed for a typical wedge head can lead to over-scavenging, and a big loss in power and efficiency.
Keeping the valvetrain stable in the hemi starts with a set of bombproof COMP lifters motivating some mondo 1/2-inch diameter Trend pushrods. Simone, along with a majority of engine builders, is of the school that stability on the pushrod side of the valvetrain trumps weight reduction, and with intake valves almost 21/2 inches wide, he needed all the stability he could muster. Even with all the bases covered, the .800-inch lift cam killed a valvespring on the first competition pull. That's right, this thing was making 855 horses with only seven candles lit!
Lighting the candles in a machine with this much cylinder pressure calls for an ignition system that is stout, but still easily adjustable. The ShotgunHemiParts.com team agreed on using an MSD Programmable Digital 7 box along with their HVCII coil and Pro Billet distributor. Using the Digital 7 allowed the team to custom tailor the ignition curve up or down based on engine rpm, and also has the ability to individually adjust the timing on each cylinder separately if a dual-sync distributor is used.
The most visceral part of being near this engine under full load is listening to the exhaust as it just violently blasts through the perfectly tuned Gilsbach Racecraft headers and Magnafow mufflers. Like standing at the fence when a fuel car launches, this dual-quad Shotgun makes your chest absolutely rattle and your eyes blur! Were the guys happy with their project? Simone summed it up best, saying, "to develop a 40-year-old engine and pick up where Ford left off, that's the real appealing thing. That's the fun part about doing this."