Shafiroff 509ci W-series With Hilborn EFI

Last time we checked in with the 509ci retro W-series big-block Chevy developed by Shafiroff Racing, it was making 615 horsepower (later tweaked to 625) and 638 lb-ft of peak torque. That was with a pair of Edelbrock 4-barrel carbs on a traditional dual-quad intake. In one of the latest versions featuring a Holley EFI system flowing into a Hilborn 8-stack intake, the numbers changed noticeably.

“We picked up an extra 50 lb-ft of torque and maybe 15 horsepower,” says Scott Shafiroff. “Same cam, same head.”

The World/BMP aluminum block accepts big-block Chevy crankshafts and timing chain. Note how the W-series design integrates the combustion chamber into the cylinder.

The engine is based on Safiroff’s popular HHR series (Hot Hydraulic Roller) and was first seen at PRI a few years ago. Development of the all-alloy package was possible following the release of the World Products/BMP 409 aluminum block. Shafiroff adds a 4.250-inch stroke Scat 4340 steel crank to the 4.370 bore, creating a 509ci bullet that provides plenty of streetable horsepower while retaining a classic appearance.

“It’s a nostalgic look that actually runs good,” praises Shafiroff.

Besides the World/BMP block and Scat crank, the short-block comprises Scat 6.385-inch H-beam rods, custom 10:75:1 pistons, Total Seal rings, Clevitte bearings, Cloyes timing chain, Cometic gaskets, ARP fasteners and Moroso pump and oil pan.

Underside view of the Edelbrock 409 cylinder head.

The HHR strategy starts with a Comp Cams “Round Lobe” billet hydraulic roller camshaft with a 7/4-swap firing order. The rest of the valvetrain includes Hi-Rev lifters, 3/8-inch chromoly pushrods and Comp Cams 1.7:1 Pro Magnum roller rockers.

The Edelbrock 409 heads receive a Shafiroff-only CNC port job and are fitted with Manley 2.250/1.750 stainless steel valves, Isky 1.530-inch springs and Manley 10-degree steel retainers.

Rotating assembly for the Shafiroff 509 HHR includes Scat crankshaft and rods, custom pistons, Total Seal rings and Clevitte bearings.

Hilborn retrofitted the EFI system to its iconic 8-stack fuel-injection manifold. Spark is provided through a MSD distributor and Moroso wires.

“It came with Hilborn’s base tune,” says Shafiroff. “Even with the individual runners, we didn’t change the cam because we wanted to start from where we were. It works so good that I don’t need to change the cam. I haven’t driven this engine in a car, but the drivability on the dyno is very impressive.”