A few months back, we brought you this article on Harrop Engineering’s kit to boost a traditional 8.2-inch-deck small-block Ford with a modern Roots-style supercharger — specifically the Eaton TVS 2650 supercharger. The old-school visuals of a positive-displacement supercharger on a pushrod small-block belied the impressive power output the team got from the kit.

Now, the Australian outfit has stepped it up, releasing a new variant of the kit, allowing its use on the larger 9.5-inch deck-height 351 Windsor engines. At first glance, it might seem odd that the company leading the way for one of the most American powerplants ever, is halfway across the globe. However, Australians love the Blue Oval as much as we do, and Ford fans are lucky that Harrop is interested in this powerplant.

The Potent 2650 TVS Supercharger

At the heart of the kit is the Eaton TVS 2650 supercharger unit. While it is indeed a Roots-style supercharger as opposed to a twin-screw-style positive-displacement supercharger, it is a far cry from what Roots blowers once were. The “2650” in the name is the displacement of the supercharger in cubic centimeters, or 2.65 liters. That displacement has been proven to be the sweet spot, as the 2650 core is in use across the industry on a wide variety of platforms, with great success.

The “TVS” in the supercharger name is probably the main key to the TVS 2650’s success. Standing for “Twin Vortices Series” the moniker denotes that the supercharger’s rotors have a 170-degree twist to them. That is not only an upgrade from the traditional straight rotors of a Roots supercharger, but an extra 10 degrees of twist over the first generation of TVS superchargers.

Additionally, the TVS 2650 redesign has led to 18 percent less input power needed, along with 25 percent increased airflow output. Couple that with an increased maximum blower speed of 18,000 rpm, and it’s no wonder the applications using the TVS 2650 make such solid power. Harrop rates the blower as capable of making 1,200-plus horsepower.

From The 5.0 To The 351

The first kit Harrop designed for the classic small-block Ford was for the venerable 8.2-inch deck-height 302 engines. While the 5.0-liter enthusiasts rejoiced, as there hasn’t been a positive-displacement supercharger kit for that engine produced in what seems like decades, the 351 Windsor enthusiasts asked, “What about us?” Harrop responded with the recently released 351 Windsor kit, which is largely the same as the 8.2-deck kit but with a custom-designed inlet manifold adapter for the wider intake port spacing that comes with a taller deck.

Like the 8.2-deck kit, the 9.5-deck kit comes available with Harrop’s heavy-duty front accessory drive, multiple crankshaft pulley diameters, and multiple supercharger pulley sizes, in both eight- and ten-rib configurations. If you’re looking to truly maximize the performance of the 9.5-deck blower kit, Harrop also offers a heat exchanger kit to keep the charge temperatures cool, as well as offering an option to include Deatschwerks fuel injectors with the kit, for an all-in-one solution.

The TVS 2650 is raised 295mm (11.6 inches) above the valley with the new spacer. While that seems tall, it certainly isn’t an insurmountable obstacle when it comes to fittment.

The standard TVS 2650 inlet for these kits is 110mm and designed to use an LS-style throttle body, but Harrop also offers different inlet orientations if you happen to be space-restricted in your application, as shoehorning a 351 Windsor into different engine bays can sometimes be tricky. Oh, and for those of you who are getting ready to complain that you don’t have a 351 Windsor, but a 9.2-inch deck-height 351 Cleveland-based combination, you’re in luck. Harrop has the Cleveland application in development as we speak.

If you happen to be in the part of the Venn diagram of enthusiasts who like both the pushrod small-block Ford engine and positive-displacement supercharger kits, you can now get a modern positive-displacement supercharger kit for your classic SBF, regardless of if you’re part of the 8.2-deck Mafia or prefer the larger displacement the 9.5-deck Windsor platform offers. Stay tuned, because we hope to bring you some real-world results of the new supercharger kit soon!