Head/Block Machining – Deck Cooling

The Audi Sport works engines from the heydays of Group B rally racing pushed the power of the 20VT I5 engines to levels that required additional cooling to ensure the engines would hold together through an entire stage of left-foot braking and high duty cycle positive boost pressures. The closed deck design of the engines, although very strong and rigid, is less than optimal for heat transfer in the vicinity of the combustion chamber. Their solution was to machine the deck of the block and head to create channels for additional cooling fluid very near to the top of the combustion chamber. This modification has been proven to allow for increased spark advance over an non-modified engine. Additionally, increased clamping pressure on the head gasket interface and more uniform cylinder head temperatures can also be realized.

You send in your bare head/block to be have the head and/or block machined to have better cooling around the combustion chambers. This is similar to what Audi Sport did with these engines back in the heyday of rallying in the 80’s. This will allow you to run more power, advance timing, and have more temperature uniformity within the area of the combustion chamber. Additionally, the reduction of surface area will cause an increase in clamping pressure and effectively strengthen the head gasket interface.