Xr6 Turbo Crankshaft

[Dr Concrete]

hey dudes

Does anyone know what the stock xr6 turbo crankshaft material is?

I know that it is a type of cast iron, but I need to know exactly what alloying elements are in it and what percentages of them are in it. The stock crank maybe able to surive 8000rpm with heat treatments to increase it strength and surface hardness along with removal of any surface imperfections, but to treat it correctly I need to know exactly what material it is. My goal is to see if we can get to power levels that have only been achieved with billet crankshafts reliably or has someone already done this without any crankshaft treatments? As billet crankshafts are way to expensive to add to other expenses when doing up one of these motors.

[rboksic]

its not in the treatments

it 's strength comes from the forging process to make the billet and the type of steel used tomake the billet.

[xlnt6]

Ask Simon @ Nizpro, I'm sure they tried heat treating/nitriding the standard cranks and ended up with distorted cranks which then either required machining to return to true or subsequent replacement. As machining removes some of the harden surface, the gain is lost. When they did my engine, they ended up tossing the treated crank and fitted a brand new crank. Hi-po engines have billet cranks, which like you said cost mucha dollar. I think based on discussions with Simon the stock crank is able to handle about 500rwKw max. This is assuming the suitable bearings are used and crank tunnel in the block has been made true.

Cheers

Robin.

[Dr Concrete]

  rboksic said:

its not in the treatments

it 's strength comes from the forging process to make the billet and the type of steel used tomake the billet.

<{POST_SNAPBACK}>

hey

dude treatments can increase a cast iron's strength quite dramatically. Technology in the casting industry has improved greatly and they are now almost matching billet and forging, but with the distinct cost advantage. If the stock crank was cleaned up of any casting marks, then stress relieved, then Austempered, machined to correct tolerances and finally nitrided it will be hell stronger than originally, thus take more kw and more revs. It sounds like a huge process, but it won't cost more than $500.