By Jason Reiss
Photography Courtesy of Roush Engines North
There’s no question that the small-block Chevrolet V-8 engine has long been the king; with well over 100,000,000 produced since its inception in 1955, it will take a long time—if ever—for another platform to even sniff its success in passenger-car and light-truck use, despite what your LS-loving buddies might have you thinking. In performance circles, the SBC has also been the go-to platform for many drag racers, but that’s changing these days thanks to the aforementioned LS and what we’ll call the unsung hero: the SB2.2 design, which is gaining acceptance as a drag racing engine configuration.
Originally introduced in 1998 as the “new” small-block Chevrolet engine designed specifically for NASCAR racing, and run through 2008 before its replacement, the Chevrolet SB2.2 engine was created in deference to several concessions—or handicaps, we’ll say—which were forced into the design as a result of the rules package for the round-track sanctioning body. In short, it was configured around solid, flat-tappet lifters; a mechanical fuel pump; and a carburetor.
Today’s SB2.2 offers the drag racer a serious platform with plenty of parts availability, thanks to the thousands of cast-off NASCAR parts—and the knowledge that went into those combinations for endurance use. While you might believe it’s a large leap to use them in a drag-racing application, we can assure you that’s not the case. One positive is that the cylinder head uses the traditional, 4.400-inch small-block Chevy bore spacing, but dramatically alters the cylinder head’s geometry to improve performance exponentially in the process.
Rather than the traditional small-block cylinder head’s layout, the SB2.2 design offers a mirrored layout, with an intake valve at each end of the head, and two exhaust valves together in the center, so the layout goes like this: IEIEEIEI from end to end. This permits separating the intake manifold’s runners with nearly equal lengths across the board. With the improved valve arrangement, these heads are considered some of the best for use with a single carburetor.
“Originally, the engine belonged to Onondaga Dragway part-owner Dan Pranshka, who I had originally helped to build the engine for, then the car was sold and went to someone else in Ohio, and eventually Don Cilli ended up with it,” Ron Sharp of Roush Engines North in Livonia, Michigan, explained of our subject engine’s history.
Don called Dan, who recommended the engine come back to Roush for a complete overhaul, which is how we ended up in the picture. We recently had the opportunity to follow along as Ron and Joe Wheeler of Roush brought the engine back to life. Don, the parts manager at Dorian Ford, resides in Clinton Township, Michigan, and fittingly, the ultimate plan for the engine is in competition at Milan Dragway and other No ET-style events held in the northern half of the country.
Serious pieces for a serious engine. Crower, GRP, and GIBTEC offer some of the finest rotating assembly pieces on the market. All of the machining processes were handled in-house at Roush, which offers its customers some of the world’s most advanced machining equipment and decades of years of experience with engine design.
Not surprisingly, the rules for the No ET events where Don will run the car are quite simple. Stock bore centers, a cast intake manifold, a single carburetor, and 28×10.5-inch slicks or 275-wide drag radial tires. That’s it. Joe says that round pairings are chosen by number in the lanes, forcing each competitor to bring his or her “A” game for each and every round since the racer doesn’t know the opponent ahead of time. The engine is used in a 1986 Mustang hatchback, is backed by a Powerglide, and runs through a 9-inch Ford reared.
Roush’s Dennis Corn tells us that this type of racing is a brand-new effort for the Cilli family, with a steep learning curve, but the Roush team is prepared to support him however necessary as he lines out this new-to-him combination.
Now, since the engine will be used in No ET events, we’ve been sworn to secrecy on some of the details. We can’t divulge everything about its construction, but we’ll share the pertinent details we do know.
Remember where we mentioned that the SB2.2 heads have the same bore spacing as the traditional small-block Chevrolet? Well, there’s a reason for that, because according to Sharp, this engine is based around a traditional small-block Chevrolet iron engine block from Dart Machinery, which uses a 9.025-inch deck height and 4.190-inch cylinder bore dimension. When these measurements are combined with the 4.000-inch stroke of the Crower steel crankshaft, they provide a displacement of 441 cubic inches—on the larger side for a small-block, but necessary to take advantage of the SB2.2 cylinder head’s high-rpm, deep-breathing capabilities.
The valvetrain benefits from a raised camshaft location, and roller bearings are used to minimize friction from the high valvespring pressures required for this engine.
High-winding engines typically benefit from lightweight rotating assemblies, and to that end a Crower steel crankshaft combines with GRP’s billet aluminum connecting rods and a custom set of GIBTEC billetaluminum pistons, which were configured specifically for this application. As is often the case with a serious build like this, Total Seal piston rings are onboard and retained by piston pins coated with Casidium for durability. Additionally, GIBTEC developed a custom button pin lock for Roush on this project.
As the SB2.2 platform was never designed for use with a Dominator carburetor, the Roush Engines team invested a substantial amount of effort into the Edelbrock SB2.2 intake manifold, which was originally built for a 4150-style carburetor a la NASCAR rules.
Not only did the outside of the manifold require hours of welding to build up its surface to allow for proper machining, the inside also needed to be tuned up to provide the plenum volume required to feed the 4500-series carburetor, which was also heavily modified in-house at Roush. We’ve seen this process in action, and it takes an inordinate amount of time to do properly, but when it is complete, it’s well worth the effort in terms of airflow and performance available from the larger carburetor and optimized intake track, which has been matched to the cylinder heads.
The SB2.2 heads originally came from Hendricks Motorsports, and the Roush crew added its custom touch to their chambers and ports, in an effort to maximize performance for the nitrous-enhanced engine. Those modifications necessitate a custom camshaft from COMP Cams, but the team was unwilling to share its grind events with us, and who can blame them? N/T cars need every advantage they can get.
“They are almost like a Ford,” Ron explained. “Instead of a traditional inline-valve head, it has a canted-valve. But it’s not a symmetrical head like a Ford, so the intake manifold becomes shorter in the middle. The plenum volume doesn’t get so big, so for an application with a cast manifold, it’s a neat little engine.”
The Roush team relies on its trusted suppliers for the products used in its engines, a number of whom are located in its Michigan backyard, like Trend Performance in Warren, Michigan, and PAC Racing Springs in Southfield, Michigan. Trend supplied 7/16-inch, .165-inch-wall steel pushrods, while PAC’s springs, titanium retainers and keys couple with the company’s spring seats to complete the spring side of the valvetrain. Del West titanium valves with hardened tips to ensure longevity are used in both the intake and exhaust positions; the valves are also DLC-coated, following the common theme of reducing friction in this engine.
With valvetrain weight so critical in this application, shaft-mounted aluminum—rather than steel—rocker arms from T&D Machine Products were selected to sit atop the cylinder heads, which rest on multi-layer steel Cometic head gaskets for maximum cylinder sealing.
Proper oiling is critical in racing engines, and the Roush Engines team consistenly achieves excellent success with the engineered dry-sump pumps manufactured by Dailey Engineering. This engine uses a custom-fabricated dry-sump oil pan with four stages pulled from the bottom of the engine and one pulling from the intake valley to reduce any potential windage losses throughout the engine.
With a full two-stage nitrous system from Induction Solutions onboard, controlling spark accurately is critical to ensure the pistons stay in the bores rather than melting down and subsequently exiting through the headers. To that end, a crank-triggered MSD Power Grid is used. Induction Solutions’ Steve Johnson supplied the nitrous system with both programmable and progressive controllers, to allow Don to dial in the system’s performance no matter what type of racing surface is presented to the team on race day.
Throughout the engine, ARP fasteners hold things together, as the performance of the company’s superior fasteners can’t be questioned in an application such as this.
What We Can’t Tell You
Although we were able to learn all of the pieces that make this engine so potent, there were a few items that we were sworn to secrecy on, including the final compression ratio (we guess it’s high, maybe 16.0:1?), the final fuel blend, which resembles a VP-ish blend, and the final power ratings. We can tell you it’s well over 1,500 horsepower, but that’s all we are allowed to share. After all, we want to be invited back to the inner sanctum of Jack’s Northern Toy Shop to cover more engine builds for you in the future.
Roush Engines North