When CB Performance decided to "freshen-up" their popular Los Panchito CNC ported heads, they went back and started from scratch for the ultimate in performance and reliability in a street cylinder head.
BY BRUCE SIMURDA
Over time, things age. IN the automobile industry, parts wear and dimensions change. That's true whether you're talking about the components in your car, or the machinery that makes these components. Case in point, the molds that are used to shape aluminum Volkswagen cylinder heads have been producing them for decades, and like everything else, have worn. That's why when CB Performance decided to rework their popular CNC ported Los Panchito street heads, they literally threw away the molds and started from scratch.
The new second generation, called Panchito 044, actually began on the computer, where CB Performance's team was able to design and add improvements to the head like never before. Areas like the fins were improved with additional webbing underneath, with clear, unobstructed passages to ensure maximum cooling. Around the cylinder seating surface, additional material was added to provide additional strength, which is needed when machining for larger cylinder diameter, or when flycutting for additional compression. But the largest part of the engineering work was done on the port design, to make them as efficient as possible. Since these heads are available only with 40mm intake and 35.5mm exhaust valves, both the intake and exhaust ports were painstakingly designed by CB Performance with testing on their Superflow 600 bench to not only flow as much as possible "as cast", but also with maximum velocity (330 feet-per-second intake, 300 fps exhaust) which equates to maximum power. In fact, on CB's flow bench, the small modified ovoid shapes intake ports (61cc port volume) flowed a maximum of 161cfm @ .600-inch with the "as cast" 54cc chambers, and 171cfm with the CNC machined 61cc chambers. Compare that to a stock 043 casting 1600 head with a 35mm intake that flows around 108cfm - that's a 58.3% improvement!
Before going into production, the head and port designs were produced in plastic with a 3D printer so they had an actual part to hold and inspect, to ensure everything was 100% accurate. The actual manufacturing of the heads is performed at Auto-Linea in Brazil, where they are cast and machined. When they arrive at the CB Performance facility in Farmersville, California, there is still a bit of work to do. Valve seats and bronze silicon guides are installed, and a 3-angle valve job is performed using their super-accurate Sunnen seat and guide machine that cuts, 30, 45, 60-degree angles. There is also a 30 degree back-cut on the intake valve to improve midrange flow. The only other machining options are enlarging the combustion chamber from the stock 54cc to a larger 61cc on their now Rotler 5-axis CNC machine to help lower compression ratio, and machining for larger 88-94mm barrels. Larger valves and porting are not options, as these babies were designed to be run "as manufactured." The only other choices available are heavier duty valve springs before they are assembled with stainless steel 40mm intake and 35.5mm exhaust valves, chromoly or titanium retainers and their Supergrip valve locks. To make things ever easier, as-cast match port manifolds are also available.
We had the opportunity to see a set of brand new Panchito 044 heads run on CB Performance's dyno, which were installed in a Pat Downs-built 2332cc engine owned by Mike "Cheez" Brown of the band Sublime with Rome. With the only mod being CNC machined chambers, and running Weber 48 IDA carbs (37mm venturis), this engine produced a maximum of 179.3 horsepower at 6,000 rpm and 183,2 ft-lbs. of torque at 4,500 rpm. As impressive as those maximum power figures are, the way that the power was delivered might be more so - the curves were smooth without any sudden surges or drops.
While the original Los Panchito air-cooled VW cylinder head was a CNC ported head, the new "as cast" Panchito 044 version offers substantial design and performance improvements - at a significantly lower price. And in this day and age, that's an amazing combination!
See the Panchito 044 Cylinder Heads Here