Weingartner 407ci Small-Block Chevy - Teacher’s Pet

On the small end of the Scat rods, a set of flat-top CP pistons hung, looking fairly ordinary. But they had some minor trickery that Weingartner had picked up over the years. Formula 1–inspired boxed forgings were used to get the best strength-to-weight ratio. Also, a narrow, short skirt cuts down on friction as the aluminum slugs move up and down the cylinders at an average speed of 50 mph. Dragging heavy rings along cast iron at those speeds creates a ton of heat and friction, so Weingartner fitted the pistons for a thin steel top ring, an equally thin napier-hooked second ring, and a low-tension oil ring. To help those thin rings seal under load, Weingartner sent the pistons to Rebco for lateral gas porting. As he is a teacher, it was second nature for him to do some quick math and figure out that with the 6.125-inch rods and 3.75-inch stroke, he would need to have a 1-inch-tall compression height. That meant there wasn’t a whole lot of meat left in the pistons. CP cut the valve reliefs the absolute maximum for those forgings to handle the monster intake valves and tight lobe separation. Any more, they said, and they would clean break.

For an added bit of safety on the bottom end, Teflon-coated Mahle/Clevite rod and main bearings were used. “I don’t know that they bring you anymore power, but the last time we fired it up, we didn’t have the distributor down all the way engaged with the oil pump shaft. So, we didn’t have any oil pressure for around 30 seconds, but the coating stayed on there and it didn’t do anything. I think that coating provides some insurance.”

“I used a Jegs standard-volume oil pump, but I ported it. I think that’s why this had such good oil pressure. I like that pump because it has such good pressure at idle.” He says that he ran the clearances at .0022 inch on the mains and .0020 on the rods, which accounted for a large portion of the high oil pressure. Often, people run the clearances really loose, searching for that last horsepower, but in the end it can cost them a crankshaft.

Atop the block’s deck sat Weingartner’s pride and joy—his own design of CNC-ported heads. For several years, he had been porting heads in his garage. With the same desire for learning he inspires in his students, he built his own flow bench to test his port designs. He’d gone through countless small-block heads and determined that he had a port shape in mind that would make the incredible torque and high horsepower required of an EMC engine. A call to Brodix ended up with a pair of bare 23-degree 10X raised-runner castings on their way to his home. If he could only sneak them past his wife. He jokes about it, but is dead serious when he says that he absolutely could not do any of this without her support. “I would like to thank my wife, Carrie, and my son, Bishop. She could have kicked my ass out of this many years ago and my son put some luck on the engine. Without them, I don’t have nothin’.”

With the bare castings now in his hands, Weingartner slowly whittled away at the aluminum, removing only the minimum amount of material that would let the right volume of air through. To science out a port can take weeks, especially when your day job is trying to put science into kids and you only have some nights and weekends to get it done. He got to a good point and decided it was time to get a professional critique. By professional, that meant driving to Reher-Morrison and having Pro Stock head porter Darin Morgan finger bang his ports. Nothing like going straight to the top. Darin gave him a couple pointers but overall it was a big thumbs-up as the little Brodix small-block heads flowed over 350 cfm on the Reher-Morrison flow bench! Right in the middle of big-block territory. Of course, it didn’t hurt that they had giant 2.150-inch intake valves.