Our friend Jeff Huneycutt of The Horsepower Monster gets to be a part of some unique engine builds. This one is no exception. Huneycutt headed over to Wilkins Racing Engines and followed along as Sandy Wilkins tore apart his standard-bore-space big-block Chevrolet NHRA Top Sportsman engine, and made some significant updates to the combination in order to stay on top and continue his winning ways.
This particular engine has been around for 14 seasons of racing, racking up round wins, race wins, and even an NHRA season championship in 2019. While components have been replaced over the years, this isn’t a case of George Washington’s axe — this is the same block as day one. It’s a Brodix aluminum 4.84-inch bore-space block with a tall 10.7-inch deck height. Part of its durability comes from undergoing the hot isostatic pressing which eliminates porosity in cast blocks.
A Proven Foundation
Also being reused is the crankshaft. It’s a Callies Magnum unit with a whopping five inches of stroke. Forged from 4340 steel, the material has been treated with Callies’ Ultra Case deep nitriding process. The crank is held in place by five four-bolt billet-steel main caps, the center three of which have splayed outer studs.
The custom pistons measure 4.610 inches in diameter and are forged from 2618 aluminum. They are drilled with vertical gas ports, and are sent to Wilkins without any valve reliefs cut into the crown — he cuts those himself in his shop. He then sends the pistons to Calico Coatings for a heat-reflective crown coating and a wear-resistant friction-reducing “anti-scuff” coating on the skirts.
The Brodix aluminum block and Callies crankshaft are both being reused. The block itself has been in use since 2011.
Connecting the pistons to the crank are pieces of automotive jewelry — MGP billet aluminum rods. The aluminum rods aren’t used in this application for their minor weight savings, but rather for the material properties. The aluminum acts as a shock absorber which can be especially critical in a violent nitrous application like this Top Sportsman engine. The rod bearings are coated and doweled, and the wrist pins are retained with buttons to help support the rings. Those rings are Total Seal pieces measuring .043 inches wide for the top and second ring, with a 3.0mm oil-control ring.
Sealing up the bottom of the short-block is a Moroso two-piece dry-sump…
Click Here to Read the Full Original Article at DragzineDragzine…