This article was originally published in Street Machine LSX Tuner #8
I HAD an 8/71-blown LS in it and thought I was on top of the world, but the authorities thought differently so I had to get rid of it,” says Tom Armstrong of his awesome mini-tubbed VK. “I couldn’t get rid of the car because I just love it, so I had Troy Worsley at Warspeed build me another engine for the VK. It is actually the third engine the car has had, after the blown motor and a 355 Holden before that.”
The VK now carries a 445ci LS stomping out an incredible 800hp aspirated, which isn’t bad considering this is Tom’s first crack at building a street machine.
“I was undecided what model Commodore I wanted to build, but I went to Summernats 30 and a few VKs there got me inspired,” he says. “I went through three VKs to find this one, which was a completely stock six-cylinder car in Melbourne. It was straight and the interior was in good nick so I wrapped that up and trailered it back to Griffith (NSW) as I wanted something easy to work with because I didn’t have a lot of experience with rust and bodywork.”
“I told Troy I didn’t want to lose too much horsepower over the blown combo,” he says of the monster-cube LS.
The core of the build is a Dart LS Next SHP block, paired with six-bolt LS7 square-port heads from Higgins Race Heads and topped with a CID two-piece intake manifold and 2000cfm FAST throttlebody for one serious E85-burning air pump. Inside the iron block is a Callies crank, Oliver rods and CP Bullet pistons for an E85-friendly 13.5:1 compression ratio, while the big-inch motor still spins to 7600rpm!
That is impressive given the 4.1-inch stroke, and Troy admits he could have spun the motor harder with a shorter stroke. However, that would have hurt the low-end torque and street driveability that he was after.
A Comp Cams solid roller bumpstick swings 270°/278° duration on Crower lifters, Iskenderian valve springs and Jet Engineering pushrods, while the REV 2.2-inch intake valves and 1.65-inch exhaust valves, plus the rocker gear are all-new. Fuel is delivered to the ports by Xspurt 1000cc injectors courtesy of an Aeromotive Pro Series fuel pump, and the air-fuel mix is fired by stock coils operating off orders handed down by a Haltech Elite 950 ECU.
A Moroso sump and Melling oil pump keep the motor from hurting bearings or ring lands, though a 35-millimetre K-frame spacer was required to fit the gigantic Ultimate Metalworks custom 2.5-inch primaries around the steering and chassis rails. Such huge pipes are required for a motor with so much snot.
“It is a weapon!” says Tom. “The torque is crazy with over 1600Nm, and it is pretty scary!” Strong words from a guy who spent years racing speedway bikes in Europe as a young fella.
The stock Trimatic wouldn’t have lasted five minutes behind the big-inch LS, so Tom specced out a serious transmission in the form of a TH400 three-speed auto packing a billet transbrake, Vasco input shaft, Daytona pinion support, and deep pan. It works with an SDE 5500rpm convertor to pass the hurt down a tailshaft to the shorty sheet-metal nine-inch diff stuffed full of good gear, including a Strange full spool, Dutchman 35-spline axles, and 4.11 gears.
The 15-inch Weld V-Series front-runners hide Wilwood disc brakes and XYZ coil-over struts, while meaty 10-inch double-beadlocked rears cover up more Wilwood disc brakes, Strange coil-overs, and a tube four-link set-up featuring adjustable arms to keep the pinion angle sweet.
Dave from Favero’s Fabrications handled the job of providing space for the meaty rear-wheel combo thanks to a generous mini-tub that Tom says was a lot harder than it first looked.
“We put a lot effort into the tubs, removing the original ones and widening them before re-welding them back in,” he says. “We tried to make the boot look original around the fuel cell. Dave also moulded the four-inch fibreglass reverse-cowl scoop to the original bonnet as I wanted to keep everything under that line and out of sight.
“When I got the car it had the original paint, but I redid the bars and mouldings,” says Tom of the factory Calais white-over-silver paint scheme. “I didn’t want to change the look too much as I like the original paint and interior because they’re clean and simple.”
Clean and simple, with a bucketload of grunt on tap sounds like the perfect recipe for a street car, and Tom is close to reaching his goal now the car has passed through engineering.
“I got it dyno’d at Matt Simms and then got it engineered in Sydney,” he explains. “We’re looking at mid-nines when I eventually take it to the track, which is pretty cool for a street-driven car.”
What an age we live in when nine-second street cars are a reality!
1985 HOLDEN VK COMMODORE
Paint: Alpine White
Brand: Dart LS Next
Pistons: CP Bullet
Cam: Comp 270/278
Heads: Higgins LS7
Pushrods: Jet Engineering
Inlet: FAST 2000cfm
ECU: Haltech Elite 950
Fuel system: Xspurt 1000cc injectors, Aeromotive Pro Series pump
Oil system: Moroso sump, Melling Select oil pump
Cooling: Custom radiator, Spal thermo fan
Exhaust: Ultimate Metalworks custom 2.5in headers, 3in system
Gearbox: GM TH400 three-speed auto, billet transbraked, Vasco input, Daytona pinion support, deep pan
Converter: SDE 5500rpm
Diff: Sheet-metal 9in, Strange full spool, Dutchman 35-spline axles, 4.11:1 gears
SUSPENSION & BRAKES
Front: XYZ coil-overs
Rear: Strange coil-overs
Chassis: Mini-tubs, adjustable tube four-link, 35mm K-frame spacer
Brakes: Wilwood four-piston calipers and discs (f & r)
WHEELS & TYRES
Rims: Weld V-Series; 17x4in (f), 15x10in double-beadlock (r)
Rubber: Mickey Thompson Sportsman S/R 26x6.00 (f), Cooper Cobra 255/60 (r)
Troy from Warspeed and Dave at Favero’s Fabrications