The Rise of Billet Engines in Time Attack

2016 WTAC Pro Class Champion, MCA Hammerhead runs a Bullet Race Engineering – billet SR20

Billet aluminium engine blocks are nothing new. They have been used for many years in high level drag racing. But outside of the professional level drag racing fraternity their use has been very rare. That is up until now. You see in 2017 there are at least 12 cars that we know of now running billet engine blocks at WTAC across four classes. The reasons for the switch to this style of engine is due to the insane amounts of power produced by the front running cars. Adelaide based manufacturer Bullet Race Engineering, a small but growing engineering firm in Adelaide is leading the billet block charge with nine top cars at this year’s WTAC boasting engines built with their products. This follows their 2016 success, with two Bullet billet blocks on the Pro class podium: in the winning car the MCA Hammerhead and also Under Suzuki’s S15 Silvia.

Bullet Race Engineering Billet 4G63 and RB26 Blocks

“An engine that made plenty of power one year might not get near the podium the next year.” said Bullet Race Engineering boss Darren Palumbo “Outputs of 1000+ HP at the wheels are becoming common at WTAC, and not just in the Pro class. We are also supplying several blocks to Open Class competitors where the competition is just as fierce.” 

Billet RB30 in production at Bullet Race Engineering

“These days it’s possible to build an engine that will put out huge power, but the cast iron blocks just weren’t built to handle it” said Palumbo. “You get distortion that can cause the block to crack, a head gasket to fail, and cylinder bores go out of round shape so you lose power. A billet block is much stronger, much more rigid under those extreme loads.”

The durability of billet blocks is remarkable. Queensland drag racer Colin Wilshire set a world record for a four-cylinder car in 2014, using an engine built with a Bullet block pumping out over 1900 horsepower to post a quarter-mile time of 6.53 seconds and a top speed of 223 mph (358.8 kmh). It is still the fastest Mitsubishi 4G63-powered car in the world, with the help of a Bullet billet block.

Bullet’s Billet 4G63, good enough to power the worlds fastest 4G63

Unlike drag racers, drivers at WTAC need to get around corners, so the extra bonus of a billet block is they’re a lot lighter, helping with weight distribution, power to weight ratio and overall handling. Nissan’s performance engine block for the GTR – the N1, weighs 70 kg, while the Bullet equivalent weighs just 40 kg. That’s a massive difference over the front wheels of a racecar.

Matt Longhurst’s Billet RB26 delivered handling advantages as well as reliability

Billet blocks are generally bolt-up replacements for the originals, but considerable effort and expertise goes into their design. “We start by measuring the stock block to get the basic dimensions, but we spend a lot of time figuring out design changes to produce a block that will withstand 500 hp per cylinder while still having the same functionality as the factory block,” Palumbo says.

SJ1000 makes over 1000hp with a Willall billet block

But Bullet are not the only billet block manufacturer either. Another Adelaide manufacturer Willall Racing are also manufacturing bespoke Subaru billet blocks one of which is featured in Dan Days SJ1000 WRX and yes that 1000 stands for 1000 hp – something a standard cast EJ block would not stand a chance at. They also manufacture billet VR38 blocks.

RP968 are taking one step further by combining a billet cylinder head with a billet block.

Rod Pobestek also recently announced he was building a ‘Full Billet’ 4 litre 4 cylinder Porsche engine for the Pro Class RP968 built in Finland by Elmer Racing and it appears they are going even one step further by creating a billet cylinder head as well whilst still retaining the Porsche architecture. This is planned to debut at WTAC 2017.

Billet blocks are not just limited to traditional piston engines, Billet Inc produce a billet rotary engine as well.

Long time RX7 competitor Jason Dorrington has also announced he will be running a billet 13B rotary engine. Produced by Billet Inc in Queensland who primarily make billet drag racing engines, this particular 13B has been built specifically for time attack racing and will no doubt bring another level of durability required to run competitive power levels at WTAC.

Once the preserve of professional drag racing outfits, billet blocks are becoming an essential starting point for many WTAC builds, even for amateur teams. “If you’re serious about competing at this level, it’s a no-brainer,” says Darren Palumbo. “You really need to be building with billet because cast ain’t fast.”

Check out this list of teams running billet blocks at WTAC 2017

Team Driver Car Engine Class Manufacturer
MCA T Slade Silvia SR20 Pro Bullet
Scorch U Suzuki Silvia SR20 Pro Bullet
RP968 B Mawer Porsche 968 Pro Elmer Racing
Notaras M Notaras Evo 4G63 Pro Am Bullet
TRP C Alexander GTR RB26 Pro Am Bullet
Gools R Gooley Evo 4G63 Open Bullet
Autotech J Wright WRX EJ25 Pro Am Bullet
Integrated M Longhurst GTR RB26 Open Bullet
S & J D Day WRX EJ25 Open Willall
WBT S Johnson GTR RB26 Open Bullet
Topstage J Dorrington RX7 13B Open Billet Inc
Micks TBA Evo 4G63 Flying 500 Bullet

For more info check out:

Bullet Race Engineering

Elmer Racing

Billet Inc 

Willall Racing