Dandy Engines-built 535ci Oldsmobile – Mill of the Month

It's not very often that an Oldsmobile donk has featured in Mill Of The Month, but rest assured this 535ci monster from Dandy Engines has well and truly earned its stripes

Photographers: Ben Hosking

Based on the five-inch bore-space Oldsmobile engine, this mill is one of a few serious bangers that found their way over here from the States and eventually into the hands of Frank Marchese from Dandy.

This article was first published in the June 2020 issue of Street Machine

“The engines were originally brought in by a good mate of mine, John Straatsma, and we did some development on them in the mid-2000s,” Frank says.

Fast-forward a few more years and Frank had taken control of the mills, and when Julian Carafa approached him wanting a new donk for his Wild Bunch machine, Frank knew just what to build him.

“The engine hadn’t run for eight years, and it’d been raced hard before that – as it’s supposed to do,” says Frank. “So we had a bit of work to do to get it up to scratch.”

The menu of shiny new gear inside the big Olds includes a Veloy billet crank, Childs & Albert forged aluminium rods and high-compression JE pistons, pushing the ratio up to 11.3. Rounding out the bottom end is a 60mm Crane Cams roller stick. A wet sump combines with a Stock Car Products external oil pump to keep the thing well lubricated as it screams its way past 8000rpm.

The top end is adorned with a beautiful pair of CNC-ported Sonny’s billet heads, carrying Victory valves with PAC springs and retainers and some beefy lifters. Crowning the whole deal is a Littlefield 16/71 supercharger, fuelled by mechanically injected methanol.

Initial dyno results showed a peak of 2081hp and 1349ft-lb on 30psi, but there’s still a lot more left on the table. “That was a pretty conservative tune, keeping it really safe,” says Frank. “It’s a real monster of a thing, and it’s still got a fair way to go.”

The lucky duck receiving over 2000hp of tarmac-bending Olds power is Julian’s 1941 Willys Wild Bunch car, set to take on the Supercharged Outlaws class. “I approached Frank because I wanted to switch to a boosted combo, and this was what we came up with,” Julian says.

He’s already taken possession of the Olds and slammed it into his Willys, and is itching to get out on track. “I’m hoping for mid-to-high sixes, and I don’t doubt the engine can do it – I’m more worried about the driver!”


FRANK and the crew from Dandy Engines know horsepower, being one of the most revered workshops in the business for building killer engines. Frank’s own XW Fairmont not only produces an eye-watering 2819rwhp from a twin-turbo SBF, but lived through five days of Drag Challenge cruelty to win the whole show in 2018. If you want big, reliable horsepower, make sure Dandy Engines is on your list.