The performance aftermarket has two very distinct niches: style and performance. We've all seen enthusiasts build thinly guised race vehicles with an obnoxious idle from ridiculous cam specs, monster carburetors, and the horsepower to back up their mechanical mayhem. Then there are those who take a more casual approach to the powerplant under the hood and concentrate on the visual elegance. This month, however, the engine-building enterprise of Scott Shafiroff Racing Engines (SSRE) blends both style and performance into a 568hp version of the classic big-block Chevy W-series engine family. It is a veteran engine builder's twist on the first-generation big-block, which enjoyed a production life from 1958 through 1963.
The 509ci W-series engine from the famed engine builder is a break from the norm—by that we mean SSRE's extensive lineup of traditional small- and big-block Chevy engines. The new W-series line takes its place in the SSRE Ultra Street lineup that spans from mild small-blocks to a pump gas masterpiece that makes power in the four-digit range. “The 409 kind of got lost once all of the other big-blocks came along. Now with the 509 that generation of car guys can have a W engine and it'll make good power,” Scott Shafiroff, owner and founder of SSRE, says.
There is a growing trend in the market with barnyard 409 W-series engine builds, but Shafiroff goes a different route with brand-new, purpose-built components. The adventure begins with a Bill Mitchell Performance/World Products 409 aluminum block. The block has some excellent features, of which the most notable is the use of a traditional big-block Chevy crankshaft, connecting rods, oil pan, starter, and timing chain/cover. The engine block can easily accept a 4.250-inch stroke crankshaft, of which SSRE utilizes, and that's combined with a 4.370-inch bore size to create the final displacement of 509 ci. Shafiroff explained to us that the bore and stroke combination wasn't pulled out of thin air. The stroke works perfectly with the block's 9.600-inch deck height and any more would yield a larger displacement, but then you start to run into compromises with the piston and rod design. The bore sizing is 4.370 inches; the largest size before the head gasket sizing becomes obscure. Shafiroff utilizes an off-the-shelf Cometic head gasket on the Street Rodder 509.
Perhaps one of the most unique attributes to the W-series style big-blocks is in the piston/combustion chamber area. The cylinder heads have a flat deck and the combustion chamber is built into the upper section of the bores. The deck angle of the block sits at 74 degrees in relation to the crankshaft centerline, where more traditional V-8 engines have a 90-degree deck surface. The angled deck creates the pocket for the combustion chamber. SSRE worked with Icon Racing Pistons on a custom design to create a 10.25:1 compression ratio. It allows the engine to run on 91-octane with no problems but still make excellent power. Shafiroff went right to Edelbrock for its Performer RPM cylinder heads, which feature a proprietary CNC-port job, custom valves, and valvesprings specific to the SSRE 509. Topping the engine is an Edelbrock Performer RPM Dual-Quad Air-Gap manifold with twin Edelbrock 600-cfm carburetors that were modified by Shafiroff—of course.
Bill Mitchell Products is responsible for the new generation of aluminum 409 blocks. The new design retains the unique 409 attributes but allows for more readily available big-block Chevy rotating assembly components and oil pan.
The COMP camshaft was slid into the BMP block. It sports a healthy 0.591/0.564 inch lift, 235/241 degrees of duration (at 0.050-inch), and a lobe separation angle of 109 degrees. The cam is a hydraulic roller setup with excellent idle, driveability, and low maintenance.
A 4340 steel SCAT big-block crankshaft with 4.250-inch stroke enables this engine to have a broad torque curve and allows a good piston design. A longer length moves the pin too high on the piston, compromising the ring package.
A Cloyes timing chain connects the camshaft to the crankshaft.
SSRE sent the Icon pistons out to get polished and coated skirts for better oil control and reduced friction. The connecting rods are from SCAT, are made of 4340 steel, and each is 6.385 inches long.
Here is a close-up look at the cylinder; the wedge-looking area above the line is the combustion chamber. This is one of the W-series engine's most unique attributes.
SSRE uses Total Seal rings on most of its engines, and the 509 is no different.
A custom BHJ ring compression sleeve is used to install the pistons due to the deck angle and combustion chamber placement. SSRE began building the 509 engines using a manual ring compressor but had the custom sleeve made to quicken the process.
Morel lifters are used in all of SSRE's serious hydraulic roller camshaft applications thanks to their durability. SSRE has put hydraulic lifters like these through the ringer in 1,000-plus horsepower racing engines—if it's good for those bullets then it is good for street applications.