The easiest part of this whole...
The easiest part of this whole build was the carburetor. Holley’s 80803 Ultra HP 750 was so well balanced out of the box that Eric Weingartner didn’t change a thing on it. It had a perfect fuel curve.
For whatever reason, we always like to root for the underdog. When the little guy gets one over on “the man,” we go nuts. Maybe it’s because we always see a little of ourselves in that underdog. He’s out there by himself against all odds, neck and neck with the money-is-no-object big boys, and we love it! That’s why when Eric Weingartner showed up with his small-block Chevy for the 2011 AMSOIL Engine Masters Challenge, everyone, including the other competitors, was rooting for him to do well.
You see, Weingartner isn’t a full-time engine builder with an unlimited budget. He’s a schoolteacher from Oklahoma. He works hard for not a lot of pay. He plays by the rules and is as honest as the day is long. He’s the guy the rest of us envy for having the intestinal fortitude to get out there and put his skills to the test against “the biggies.”
Using a ported Dart intake...
Using a ported Dart intake manifold with a Dominator-style carb flange, an HVH Super Sucker carb spacer blended the transition into the runners. The Ultra HP carb comes with slotted mounting boltholes so it can be bolted onto either a standard 4150 intake or a Dominator intake like this one.
Weingartner has been a pretty hard-core engine guy for a while now and though this wasn’t his first trip to the EMC, it was a chance to show what he’s learned over the years. What he’s learned is that he knows how to make more than 600 of those wild Oklahoma horses run fast without a lot of compression or high octane. Weingartner also knows what parts can be a little more friendly to a workingman’s budget and which ones not to skimp on.
The foundation of this 407-cube build, the engine block, was something he absolutely didn’t want to skimp on. He called World Products and ordered one of their splayed-cap SBC 400 Motown blocks, which is different in one key respect: the old-school factory 400 blocks were built without siamesed cylinder walls. What that means is the cylinders have an open water passage next to one another. Good for light weight and low production cost, but bad for keeping the cylinders stable when making lots of torque. The World block uses siamesed cylinder bores for that extra strength. He had his favorite local machine shop, Dunsworth Machine, bore and torque-plate hone the block. Dunsworth’s specialty is circle track engines, so Weingartner was comfortable with the way they machine blocks for endurance and reliability. When asked what tricks they did on the bores, Weingartner was honest about it: “I said do whatever it takes to get it right. I honestly don’t even know what they do. They build a ton of engines and whatever they do works. I check the taper on the bores, and it’s always perfect.”
With the raised runners on...
With the raised runners on the heads, a bit of epoxy was necessary on the floors of the intake runners to get them to line up right.
Part of that endurance philosophy was seen again when Weingartner picked out a forged steel crank from Scat. The superlight crank still maintained the heavy-duty 400 main journal sizes and standard 2.100-inch rod journals. Keeping that standard rod journal with a 3.75-inch stroke meant that some minor block clearancing would be necessary so the rod bolts didn’t try to cut their way through the oil pan rails. Another part of making the engine live in a grueling environment was the decision to internally balance the crankshaft. Stock Chevy 400 cranks were cast iron and required their own externally balanced flywheels and harmonic dampers. Changing to a forged steel crank adds some density to the shaft but the counterweights still weren’t heavy enough to balance it out on their own, so Dunsworth had to add a few small sticks of extremely dense tungsten to each end of the crank.
Also from the Scat lineup, Weingartner picked up a set of I-beam connecting rods. He felt that at the power level he was at, there was no need for the super high-dollar rods. Those sportsman versions would do quite well, thank you.