Unlike some of the later dry-sump–only...
Unlike some of the later dry-sump–only Chevrolet race blocks, the Bow Tie block comes with provisions for a standard small-block Chevy oiling system. The oil pump is a standard Melling replacement.
Working with the cylinder heads is an Edelbrock single-plane manifold. This top end combination uses a separate valley plate with divorced runners in a separate spider assembly. As with the cylinder heads, Clark handled the porting on the manifold, working the full length of the runners and modifying the plenum form. This manifold is designed for a standard 4150 carb flange, and to run with a 1050 Dominator’s 4500 flange, an adapter from HVH was used. The HVH adapter features a tapered form below the throttle plates that improves the transition beneath the large bores of the Dominator carb.
Finishing the assembly is a set of Schoenfeld sprint car headers, featuring 1¾ to 1⅞ stepped primary tubes. Buck spoke highly of these headers: “I think Schoenfeld is one of the best header manufacturers in the United States. We use them on all the round track motors around here.” Providing the fire is a complete MSD ignition system, using an MSD billet distributor, a 6A ignition box, and a Blaster II coil along with MSD wires. Buck explains that the MSD ignition components have served him well. “I use the MSD on the dyno and on the cars we run. I’ve never even had a box go bad. I kept it simple with a regular distributor.”
The real secret to this engine’s...
The real secret to this engine’s outstanding power production are the GM SB2.2 cylinder heads. These are dedicated race castings with a completely revised port and valve layout. Clark Hinkle’s port work put the flow at 400-plus cfm at .700-inch lift.
Hinkle’s engine was assembled just in time to make it to the 2011 Engine Masters Challenge competition, with little time for testing. Buck elaborated: “I just got it together and really didn’t have time to try different parts combinations—it was run just how I first assembled it. I did have a few things that could have been tested, like a set of higher ratio rockers, and running even more compression. In the end, I think we missed the tune-up as far as air/fuel ratio on the carb, and it hurt the power output, but it still delivered good power.” With peak power coming in at 736 hp at a reasonable 7,000 rpm, and nearly 600 lb-ft of torque on hand from just 385 cubes, there is little doubt of the power capability of these racetrack engine components.
A dedicated rocker arm arrangement...
A dedicated rocker arm arrangement is required for the SB2.2 heads, and it is unlike anything you’ll see for a standard Chevy small-block. The rockers come from T&D, with a ratio of 1.75:1. The Hinkle crew also had a set of 2:1 ratio rockers, but time constraints did not allow testing the increased ratio.
It’s no secret that the big boys in pro circle track racing chew through top-shelf parts like no other group in racing. In fact, as the state of the art or specs change, entire engine programs are liquidated to make way for new parts. Many of the parts used by Hinkle Performance Engines in building this SB2.2 Chevy were scooped up at local auctions, often held in Southern states. The auctions are where some unbelievable bargains can be found, however, items are often sold in bulk lots for local pickup. Much of this stuff is bought by outlet dealers who sell the bulk lots off piecemeal. These sellers and their inventories can be found with a little Google searching with keywords such as “used,” “NASCAR,” “engine,” and “parts.” You may not get rock-bottom auction prices, but the prices are generally a fraction of retail.
For those outside NASCAR country, many of these parts filter into more mainstream sales venues, such as eBay.com, or listings on RacingJunk.com. In fact, most racing and enthusiast message boards have parts listing pages where a variety of these parts come up. Enthusiasts can take advantage of a direct pipeline from Roush-Fenway and other top NASCAR teams by checking out the offerings at RoushYatesParts.com. They have stepped up with over 40,000 square feet of warehouse space stocked with inspected and cataloged used racing parts. This huge inventory of used racing parts is listed at very reasonable prices, with shipping available worldwide.
With the high rpm capabilities...
With the high rpm capabilities of the SB2.2 heads, a lightweight valvetrain becomes a major asset. These Del West titanium valves measure 2.160 inches (intake) and 1.600 inches (exhaust).
These cylinder heads feature...
These cylinder heads feature a compact 51cc combustion chamber with ample quench areas on both sides of the deck, which delivers a final compression ratio of 13.5:1 with the dished pistons. Note the streamline port bowl form.
Feeding the beast is a much-modified...
Feeding the beast is a much-modified Edelbrock intake manifold. The mix is provided by an old-style Holley 1050 Dominator.
An off-the-shelf set of Schoenfeld...
An off-the-shelf set of Schoenfeld sprint car headers handle the exhaust. The headers feature a stepped design, with 1 3/4-inch primary tubes at the exhaust port stepping up to 1⅞ inch. Note the crankcase evacuation system plumbed into the collectors.
Crower .875-inch solid roller...
Crower .875-inch solid roller lifters follow a custom COMP cam. Camshaft specs are relatively conservative for an engine of this level, using 249/254 degrees duration at .050, and delivering .756 inch of lift with the 1.75:1 rocker ratio. The intake lifters feature an offset seat to better align the pushrods with the rockers.
Mating the 4500-Series Holley...
Mating the 4500-Series Holley to the 4150-flanged intake is a tapered spacer from HVH. The tapered spacer is especially effective with a 4500-Series carb, since it fills in the void areas below the widely spaced bore centers of the big carb.
Hinkle Performance is a firm...
Hinkle Performance is a firm believer in the reliability and effectiveness of MSD ignition components. This engine relied on MSD throughout, including the distributor, coil, wires, and 6A ignition box.
On the dyno at the AMSOIL...
On the dyno at the AMSOIL Engine Masters Challenge, the engine produced a peak of 598 lb-ft of torque at 6,100 rpm, with power coming in at a peak of 736 at 7,000 rpm.
With the performance turned...
With the performance turned out by their small-block Chevy engine combination, Buck (left) and Clark (right) Hinkle have plenty to be proud of. These men are veteran competitors.