Knight Engines-built 383ci Holden V8 combo

Holden V8 guru Tony Knight pieced together this 383ci combo for a customer and it's an absolute screamer

Knights Engines Holden V8
Photographers: Troy Barker

If, like me, you’ve spent an unholy amount of time researching Holden V8 engine combos on the internet, you’ve no doubt come across Tony Knight of Knight Engines. Tony is something of a guru when it comes to Holden’s venerable homegrown bent-eight, and this 383ci combo he pieced together for a customer is an absolute screamer.

First published in Street Machine’s Summer Special 2023 magazine

The VT block has been grout-filled and treated to a set of M&W four-bolt main caps and a Chev seal conversion, along with the usual kinds of oiling mods required to get a max-effort Holden V8 to live. The bores were punched out 30thou, then torque-plate honed and plateau finished.

The crankshaft is a Scat 3.75in steel item, to which cling Callies small-journal 5.7in rods and, in turn, Manley pistons with Total Seal rings, with compression coming in around 13:1. The oiling system consists of an ASR Drag Comp 9.0-litre pan, and a modified JP high-volume pump with an external pick-up and bronze drive gear.

The camshaft was ground to Tony’s specs by Crane, and it’s a solid-roller sporting some 278/284 degrees duration on 109 centres and around .740/.700in valve lift. Lifters are BAM solid-roller items, with Crow .110in-wall, 5/16in pushrods conveying the bump to Yella Terra Platinum rockers. Isky springs, Manley retainers, and titanium locks and spring seats have been used up top.

Rather than the more widely favoured VN-style cylinder heads, Tony opted for early-style heads, but good ones. The castings are 25-year-old Yella Terra dash three items, which have been ported to within an inch of their lives and wear Manley 2.08in inlet and 1.6in exhaust valves. “It’s max-effort porting; those heads are pretty much maxed out,” Tony says.

The tunnel ram was custom built by Bain Racing to suit this combo and wears a matching pair of Holley Ultra XP 750 E85 carbs. The ignition system is all MSD, including the crank trigger, Pro-Billet distributor, Power Grid ignition and 8.8mm leads.

It’s been dynoed at a meaty 723hp on C85 fuel, and if there is a more powerful NA early-headed Holden in existence, we haven’t seen it. And yet, Tony reckons there’s still room for further development.

“We’ve got enough data to step it up in the future,” he says. “The 750 carbs are holding it back; they start to hurt power at 7000rpm – you can easily see it flatline on the graph. However, it holds the power past 8000 and has a 2000rpm spread from peak torque to peak power, which tells us the cam and heads are likely capable of more. So next time it’ll get 950 carbs, which alone should nudge it up around 750hp.”

Tony also let it have 38 degrees of timing on the dyno with no signs of detonation, suggesting it can handle more compression. With a change to custom pistons and 14:1 comp, along with a set of 1.8:1-ratio Jesel rockers to yield .800in valve lift, Tony reckons we could see this mill produce between 750-770hp after its next freshen-up.

Long live the Holden V8!

Up front

There’s plenty of killer hardware riding up front of the little 383, including a MagnaFuel billet four-port fuel pressure reg, Moroso four-vane vacuum pump and vacuum relief valve, Moroso BBC drive mandrel and pulleys, Moroso remote thermostat housing and a CVR electric water pump.

Knight Engines,
Somerton Park, South Australia