Dandy Engines 634-cube big-block Chev combo

Keith Hards charged Dandy Engines with the task of building an engine to take out the radial aspirated class at Drag Challenge, and this 634 is the result

Photographers: Shaun Tanner

Turbo combos capture plenty of attention at Street Machine Drag Challenge thanks to their epic power potential and great street manners. Still, they can’t match the appeal of a tough-as-teak, big-inch aspirated V8. Keith Hards has brought his sweet ’69 Camaro along to three DC events now, but he’s now stepped up the F-body’s tilt at Pacemaker Radial Aspirated supremacy with a new rat motor courtesy of Frank Marchese and the Dandy Engines crew.

First published in the January 2023 issue of Street Machine

“Our goal was to run with Al Vella, the leading car in the Pacemaker Radial Aspirated class,” Frank says. “Hats off to Al; he’s not only run the numbers but he’s made that car live on the road, too, and that is a huge part of the challenge.

Lucky for us, the Camaro had a big-block in it, and that’s what we are going with, as it becomes a little bit easier. But nothing is easy when it comes to pushing these limits.”

Built off an iron 10.2-deck-height Dart block, Keith’s Camaro is rocked by a billet Bryant crank, Oliver steel rods and custom Diamond pistons for an enormous 634 cubes (10.4 litres!). The heads are alloy 14.5-degree castings from Sonny’s Racing Components, and they’re topped by a sheet-metal high-rise intake wearing injectors in the inlet runners and a pair of 4500 Dominator-pattern Accufab air-only throttlebodies.

Without turbo, blower or nitrous power adders to pump up the horsepower, angry aspirated combos like this live and die by their cam specs. The stick in Keith’s mill is a custom solid-roller with a larger 55mm core than what Mark IV big-block Chevs normally run.

“We can still go bigger on the cam, as it is done to suit the street compression this engine has,” Frank explains, before pointing out that the all-important valvetrain set-up can also be an NA pushrod engine’s Achilles’ heel.

“Keith’s engine previously had aluminium rockers and they didn’t like street duties, so we had a failure at Drag Challenge Weekend 2022,” Frank says. “Being a big-block, they run a big valve that is heavy, so it does need spring pressure to control that. We used good parts like the shaft-mount Jesel rockers and Jesel tie-bar lifters, but we don’t know yet whether this engine will have issues with what Keith’s Camaro has to do both at the track and on the road. Still, this one goes straight to 8300rpm like a small-block!”

The monster-cube fat-block has so far made over 1200hp on the dyno, and pushed Keith’s 3480lb pony car to a 8.38@162mph best in testing at Heathcote. Yet Frank reckons there is plenty left on the table once the Camaro no longer has to endure the road-leg torture test of Drag Challenge.

“The engine is nowhere near maxxed out yet; it’s only 12.0:1 compression!” Frank laughs. “A maximum-effort big-block with 16:1 comp would make another 80hp, but this engine has to be well-mannered on pump fuel, live on the street and tow a trailer at Drag Challenge. We don’t have an unlimited budget like an F1 team, so we can’t be 100 per cent confident this will work absolutely faultlessly. There are no guarantees in this game.”

This BBC is far from a slapper, though, and the Dandy crew have put a huge amount of work into ensuring it will live a long life. “Keith and I are two guys having a crack; we don’t have all the magic answers,” Frank says. “But we know where we should try different things. We tried different piston designs to find an edge for this combo.”

UPDATE, February 13 2023: The 634-cuber did the trick for Keith Hards, the Camaro leading the Pacemaker Radial Aspirated class from Day One through to the final day to take the win.

His campaign got off to a roaring with an 8.51 @160mph, and he backed that up again on the final day with a best for the week of 8.49 @160mph.

Those numbers also put him seventh overall in the results, but don’t be fooled into thinking the big-block didn’t make Keith earn those cherries.

“I’m absolutely wrecked, it’s been a bloody big week,” he told us on the final day. “It seems to be the big-block curse to have valvetrain issues, and we’re in that boat,” he continued. “We’ve broken a few rockers, and when we pull the (valve) covers there’s brass everywhere.”

Keith was humble but quietly stoked to grab the win, and he’ll be back for another charge to try and hold the Pacemaker Radial Aspirated title later in the year.

Great aspirations

Getting an aspirated street engine to make four-digit power reliably is no mean feat and requires a lot of development.

“We started with a four-barrel intake as a baseline and we saw what the car did, so when the time was right, we upgraded to this sheet-metal manifold,” Frank says.

Dandy Engines
Dandenong, Victoria