Hi Guys,
I know this has been mooted on a couple of occasions but I need to pursue the possibility of swapping pistons from another Jap motor. I'm thinking that if I can use a standard piston from, say, a 450 Honda having a bore of 70mm, this would be the equivalent of 1mm oversize on the std 400 bore. There are loads of options in this size alone and I haven't looked at the equivalent Imperial possibilities. I can do any machining of the piston mods in-house incl balancing etc., and would only need to pay out for the rebore and the new piston sets.
I would prefer not to pull my bike off the road to measure the piston dimensions and would ask if anyone has a piston lying around that they could accurately measure for me that would be great. The essential dimensions:
The wrist/gudgeon pin diameter
the overall height of the piston from skirt to crown
the dimension from the centre of the pin to the crown
Information about the shape of the top would also be useful ie flat with valve pockets, crowned etc. A photograph would be a huge advantage.
Happy to keep you up to speed as I progress with this project.
I know this has been mooted on a couple of occasions but I need to pursue the possibility of swapping pistons from another Jap motor. I'm thinking that if I can use a standard piston from, say, a 450 Honda having a bore of 70mm, this would be the equivalent of 1mm oversize on the std 400 bore. There are loads of options in this size alone and I haven't looked at the equivalent Imperial possibilities. I can do any machining of the piston mods in-house incl balancing etc., and would only need to pay out for the rebore and the new piston sets.
I would prefer not to pull my bike off the road to measure the piston dimensions and would ask if anyone has a piston lying around that they could accurately measure for me that would be great. The essential dimensions:
The wrist/gudgeon pin diameter
the overall height of the piston from skirt to crown
the dimension from the centre of the pin to the crown
Information about the shape of the top would also be useful ie flat with valve pockets, crowned etc. A photograph would be a huge advantage.
Happy to keep you up to speed as I progress with this project.
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