Frenzel Supercharger – Mill of the Month

Only 12 Frenzels were originally produced back in 1949, making them an esteemed early blower for Henry’s venerable sidevalve V8, the ‘flathead’

Photographers: Ashleigh Wilson

TRADITIONAL hot rodders have a strong affinity for vintage powerplants and the niche aftermarket offerings that go along with them. Fashioning and driving period-sensitive rods is a way of connecting to the pioneers of both drag racing and automotive modification.

First published in the February 2022 issue of Street Machine

It’s that passion that led mates and Barons Moto Club members Tim Miller and Paul Mortimer to reissue the uber-rare Frenzel supercharger, under the Frenzel Supercharger Co banner.

Only 12 Frenzels were originally produced back in 1949, making them an esteemed early blower for Henry’s venerable sidevalve V8, the ‘flathead’.

Tim and Paul knew the scarcity of the American-built blower, so when one popped up for sale in Australia, the pair snapped it up to use as a base for producing new Frenzels.

“In 1949, Frenzel was the only supercharger that sat vertically, using spur gears, which meant the unit consumed less horsepower,” Paul says. “It was said to make up to 6psi, whereas the McCulloch supercharger sat flat or horizontal and was said to make around 2-4psi – if the stars aligned! The original advertising and testing showed up to 40 per cent additional horsepower by adding a Frenzel to a stock motor.”

While there’s no fresh figures from the newly minted blowers, it’s of little consequence to keen enthusiasts chasing nostalgia over power. For Tim and Paul, authenticity is their key focus.

“We’ve strived to recreate the unit exactly like the one built in 1949, taking patterns directly from the original, then casting in 601-grade aluminium,” Tim says. “We’ve spared no expense in making sure every little detail is correct, from exact recreations of the impeller through to having them dynamically balanced and weighted to match the original. That’s why the pulleys and gearing are also handmade – to be true to the 1949 production. We could have saved money by cutting corners, but we wanted to do it right.”

The reissued Frenzel features a 71⁄2-inch impeller that’s been CNC-machined from high-tensile alloy, with a 3.93:1 gear ratio. Twin-belt pulleys on both the water pump and crank are required to run the blower; these are all available new, along with tensioners for both the early- and later-style flatheads.

Also on offer are new dual-carb manifolds to suit Stromberg carbs, along with the Strommies themselves and linkages – the lads have done this to keep with Frenzel’s original design.

The first two prototypes were put through the wringer on two different engines in Tim’s 1930 Model A roadster – one an early, 21-stud, 221ci flathead that he used for The Rattletrap beach sprints earlier this year; the other an Isky-cammed 8BA. However, for our photoshoot, the Frenzel was strapped to a 50s show-inspired donk dubbed ‘The Golden Nugget’, a stock, low-compression, 8RT-headed 239ci flathead.

Tweaks were made with each prototype, and now the first production run of 20 units is underway. “The first lot of superchargers will be finished early in 2022 and shipped off to our waiting customers,” Tim says. Pricing is yet to be determined.

While an American company has recently launched its own version of the same blower, Tim and Paul have trademarked the name and believe their product is the most accurate reissue of the Frenzel.

So if you’re keen to strap a sweet Frenzel blower to your flatty, check out @frenzelsupercharger on Insta or head to


Much of the Frenzel supercharger story is steeped in mystery, though Paul and Tim plan on nailing down as many details about it as they can, as a tribute both to the blower itself and its race-going creator, whose first name remains the subject of conjecture.

However, everyone tends to agree that in 1949 Mr Frenzel produced 12 units, three of which were stolen en route to a California speed shop. Recently a registry of those that remain was set up, with nearly all vintage pieces now accounted for.