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Then MSC is worth a look for a 1m length of 3/4" SS £34 plus VAT & Postage
Hate to think how long it would have taken you to get to this stage if you did not have the "rapid Production" lathe Will C4 have a single crankshaft with one or two flywheels? And will you have to use different bearing supports to avoid a long overhang or use the existing castings and cobble something together to support the cam followers?