All you need to know:Crankshafts

Obi San not wanting to start a war just wanting to clarify things :)

The pistons stroke is determined by the crankshaft so the EXACT same piston can be used in a longer stroke application with a shorter rod length to stop the piston crown @ TDC extending past the top of the block however I would not recommend using shorter rods as that increases the piston skirt side loading .

As an example my motor is a 4G63 (2.0 litre 88mm stroke) stroker where I have installed a 12mm longer stroke crank from a 4G64 motor (2.4 litre 100mm stroke) in a 2.0 block which increases the capacity to 2.3 litres .

To do this the forged pistons fitted to the forged standard length 2 litre rods have the gudgeon pins raised 6mm (1/2 the increased stroke) and unfortunately that has lowered the rod ratio from 1.7 to 1.5 which has limited my redline to 7200 rpms

I have started a new thread "Rod Ratios" for those who want to know more about the subject :)
 
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Good article. A picture of the crankshafts would be good comparing flat plane to cross and the floating arm one.

It was quite informative and written simply so I could understand it.

What is crank grinding and knifedging and how does this improve performance?
 
Much appreciated @TCJBOLDIE I'll make the article a little clearer.

@thexav I don't have any pictures to use but I'll ask around and try and get permission to use some pictures from another tuner.
 

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