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| Cosworth connecting rods are forged (not just machined) from high nickle and molybdenum 4340 alloy (EN24 for you non SAE brits). 4340 is much stronger and tougher than regular steel to better withstand cyclic loading. Cosworth rods are H-Beam which is the strongest in the direction of normal stress for a connecting rod and have bolts with a 260,000 lb tensile strength. Serious stuff. Although Cheston’s engine is a budget piece, he does not hesitate to spend money where it does the most good. |
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| Cosworth forged turbo pistons are made of a proprietary Cosworth spec alloy, COSAl 010. They are a strut type piston and every piston design uses its own uniquely designed forging die for the best strength to weight possible. Technosquare sent the pistons out to Swain Technologies to receive their special gold coat multi layer thermal barrier coating on the domes with PC9 heat conducting hard skirt coating for less bore wear and friction. The dished turbo pistons feature a 8.8:1 compression ratio. |
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| The two grooves above the top ring groove are anti detonation bands. These help buffer the shock waves produced by detonation so they won’t upset ring seal. The bands also help dissipate the shock wave to protect the rings as well. Removing material reduces growth and scuffing as well. The piston pin is fed by dual pin oilers and retained by round wire locks. |
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| The underneath of the piston shows the notch for the oil squirter and skirt milling to reduce weight. The piston strut walls cant outward to increase the skirt area to reduce contact stress while still having the light weight of a strut type design. |
