WIX Archives

Casting and Forging

Posted by Joe Scheil on Sun Jul 13, 2003 10:27:18 AM

In reply top So.. Merlins were cast....? posted by Elliott on Sat Jul 12, 2003 05:30:19 PM

Merlin crankcases are castings, with machined inner surfaces, that is true. There was comparitivly little to machine out as the castings were pretty close to spot on. Things like the crankshaft are forged, very similar to automotive use. A forged steel crank is taken from a long piece if steel and is hammered into shape to make the throws, then machined. The cast cranks are lower performance applications. There are also billet cranks made for special appications machining them out of a solid piece. I believe that forged cranks are sligtly stronger over time, but billet is used for racing as it has a short lifespan anyway. Large aluminum castings are very complex due to many factors, and are done only by specialty shops. Dove, Merlin and Mercury Marine do modern racing engines. Falconer blocks for the V-12's are some of the largest, if not the largest done today. When Chevrolet decided to build and Market the LT-5 motor in its special ZR-1 Corvette, GM found it was too hard to make the aluminum castings themselves for the engine blocks. Mercury Marine was contracted and they made the several thousand engines as a subcontractor. There is some great information online regarding racecar modifications from street engines, this is a great place to start..

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