When it comes to the cylinder head, Audi gave us a good start again with four valves per cylinder. But 034 overlooked nothing. To cope with the higher rpm, there's a solid lifter conversion, titanium valve spring retainers and high-rate valve springs, which are well suited to the high cam lift as well.
According to 034, this cylinder head would be good for up to 12000rpm, assuming the bottom end held together.
For improved air flow, the stock valves were replaced by a custom set of stainless steel valves that are 2mm oversized on the intake for improved flow. They're also nitrided for durability. The inconel exhaust valves are 0.5mm larger to improve flow and withstand the extra heat.
The 034 crew also ported and polished the intake and exhaust ports. Coupled with the increased valve diameters, this process significantly increased the flow potential. In fact, after testing on a third party's flow bench, the head now flows 25% better on the intake side and an impressive 35% on the exhaust side.
In order to retain a favorable power band for the testing to come in the Top Shop Challenge, 034 decided not to get too radical with the cams, settling for Belgian 268 Cat sticks for both the intake and exhaust, with 11.2mm lift and an adjustable lobe center from 110-120.
Although not extreme, these profiles represent a significant improvement over the stock 224 Audi camshafts that only offer 10.5mm lift on the intake valves and 213 duration, with 9.6mm lift on the exhaust valves.
As mentioned, 034 isn't playing around. In fact, a built long block like this would set you back about around 30 big ones!
Stay tuned to future issues where we'll see what 034 will use for fuel, ignition and - the fun part - turbocharging. There's currently a debate between the Garrett GT42RS, GT45R or GT47R dual ball-bearing turbos. The one that provides the best power curve will be fitted.
Oh man, the other teams don't know what they're up against! To discover more about the Castrol Syntec Top Shop Challenge, vote for your favorite builder (034!) and enter to win the best engine, log on to www.SyntecTopShop.com