http://articles.sae.org/13388/
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CGI cylinder block in aluminum structure
The 2.7-L is based on an all-new V6 architecture; it's not part of the 3.5-L family. Bore and stroke dimensions are a "square" 83 x 83-mm. Bore spacing is 95 mm/3.74 in, and the cylinder bank offset is 35 mm/1.38 in.
The dohc, four-valves-per-cylinder engine employs twin-independent continuously-variable valve timing (TI-CVT), with the phasers operating in a range of over 30º. Ford is able to use TI-CVT to eliminate the need for an exhaust gas recirculation (EGR) valve. Compresson ratio is 10:1.
The linerless cylinder block is compacted graphite iron (CGI), Ford's first application of this material in a gasoline engine. Proven on the latest generation diesels and some racing engines, CGI is a high-strength material with excellent heat transfer properties. Compared with grey iron, the CGI cylinder block offers approximately 75% higher tensile strength, 45% greater stiffness and roughly double the fatigue strength, with excellent dimensional stability, durability, and NVH damping characteristics, according to Ed Waszczenko, Ford's V-Engine Design Leader. He noted that Ford also used CGI in the 6.7-L Power Stroke V8 diesel (which influenced the design of the 2.7-L's block, offset I-beam connecting rods, reinforced-plastic oil pan, and pistons) as well as in the 2.7-L light-duty diesel co-developed by Ford and PSA for European applications.
CGI's strength properties allow for thinner-section cylinder block walls and narrower main bearing saddles. The CGI block is actually one of two main structural elements of the new V6's lower end. The other main element is a die-cast aluminum ladder frame which envelops the lower portion of the CGI element and bolts to thick flanges on each side of the cylinder block. Heavily ribbed on its exterior for added rigidity, the ladder frame also supports the precision-fractured main bearing caps.
The bearing caps, also in CGI, are laser-etched at an angle, Waszczenko explained. The specific angle creates a wedge effect that when the sections are merely set together, the engine actually would be able to run without the cap bolts.
The small (top) end of the con rod does not contain a piston pin bushing. Instead, the rod's pin bore is slightly convex, to allow for flexing of the pin, and is silicone-coated. Eliminating the bushing permits a slight reduction (3.0 mm) in deck height of the engine, which is 218.3 mm (8.60 in). The exhaust manifolds are cast integrally with the cylinder heads, which produces a compact overall structure and improves heat transfer—necessary for fast catalyst light-off. At the front, the accessory drive pulleys are mounted to a single, rigid aluminum casting.
The cooling system is a reverse-flow: Once the thermostat opens, the coolant flows from the pump through both the heads and the exhaust manifolds, and then down and through the block.