They say turbos are the replacement for displacement, but this 869hp big-block Chevy proves there is still plenty of life left in the old rat motor platform. Bill Kaglatzis from BK Racing Engines in Sydney still proudly flies the flag for carb-fed aspirated combos, and when they work this well, who’s to argue?

First published in the February 2026 issue of Street Machine

“We sell an 850hp big-block Chev combo as a package motor that customers can buy from our website, but we still like to find gains where we can,” Bill says. “This engine has a few upgrades over the normal big-block package, as the customer wants to do everything in his car: Powercruise, Drag Challenge, cruise it on the street, and take it down the highway. So, it has to work in a lot of different environments.”

Based around a standard-deck-height 9.8in iron Dart block, the angry rat swings a 4.250in-stroke Scat crank, Callies Compstar rods and 11.8:1 RaceTec slugs, so it’ll run sweet on 98RON pump unleaded. A custom mechanical roller cam ground to BK’s specs provides the chop, while .905in BAM bushed lifters and Yella Terra Platinum rockers round out the valvetrain with some quality hardware.

The big 4.600in bore allowed Bill to run 300cc AFR oval-port alloy heads, even though they’re not the biggest or baddest option. “They’re a small port for a big-block,” he admits. “It’s built like a torque monster, as the huge bore allows the head to flow more.”

Sitting on top of the Weiand Track Warrior single-plane intake is a twin-blade APD carburettor. “This twin-blade carb is where we found gains over the traditional engine package we’d build,” Bill says. “This combo would normally come with a Dominator carb, and the last time we ran one of them it went 851hp, but this went 869hp at 6200rpm and 800lb-ft at 5200rpm. We like to add a twist to our packages for the customer, and we’ll take any opportunity we can to make more power for them.”

The BBC’s front-drive wears a Jones pulley kit to handle the revs this combo can produce. “The problem with a lot of the big-block accessory kits you buy is that they’re all billet and shiny, but not designed to go over 6000rpm,” Bill says. “We decided to do the Jones kit because we know it’ll hang in there.”

Spark is provided by an ICE Ignition distributor and lead combo, while the Moroso oil pan keeps everything spinning nicely.

“We’ve looked for areas we can give a little twist to our regular combos,” says Bill. “This engine will suit the customer’s intended uses better, and who doesn’t like a bit more power?”

BLADE RUNNER

The bad old days of dancing the two-step to get your carb to cold-start are pretty much dead, according to Bill. “Modern carburettor manufacturing with CNC machining means we can repeat results time and time again,” he says. “These twin-blade APD carbs fill a gap between 4150-pattern carbs and the 4500-pattern Dominators, and they have more manifold options, too.”

BK Race Engines
Bankstown, NSW