This might need moving but look here
http://www.mitaka.co.uk/
Interesting reading
ALL YOU PISTON DESTROYERS
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Train Driver
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dirtyhandslopez
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And there you have it.
Thank you.
Thank you.
That's not going anywhere...
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soulsurfer
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Interesting...
"On the subject of forged versus cast pistons, it should be understood that there are pros and cons which are well understood by the Motorcycle manufacturers. Cost is not an issue since the difference at high volumes is negligible. No manufacturer would compromise the performance of a racing bike for a small cost reduction. A forged piston is stronger but cannot not be made from the optimum silicon content alloy and this will require a larger clearance which will always compromise its performance. Of the four Japanese manufacturers, only Kawasaki has used forged pistons in its two strokes and they abandoned the practice 20 years ago. The highest specific power output achieved by a modern mainstream two stroke is the Honda RS125 G.P. Racer. 50 h.p. - Yes 400 h.p. per litre (more than an F1 car or a Moto GP bike) and this is using a cast piston (the KTM85 is also close to this performance with a cast piston). Why - because this is the only way to achieve the clearances needed to maximise the power output. A forged piston may perform better when working outside the service limits, but this should not be an attraction for a racer."
I was told about different rates of expansion and distortion between the two and that cast pistons are better for air cooled and forged better for liquid cooled engines
"On the subject of forged versus cast pistons, it should be understood that there are pros and cons which are well understood by the Motorcycle manufacturers. Cost is not an issue since the difference at high volumes is negligible. No manufacturer would compromise the performance of a racing bike for a small cost reduction. A forged piston is stronger but cannot not be made from the optimum silicon content alloy and this will require a larger clearance which will always compromise its performance. Of the four Japanese manufacturers, only Kawasaki has used forged pistons in its two strokes and they abandoned the practice 20 years ago. The highest specific power output achieved by a modern mainstream two stroke is the Honda RS125 G.P. Racer. 50 h.p. - Yes 400 h.p. per litre (more than an F1 car or a Moto GP bike) and this is using a cast piston (the KTM85 is also close to this performance with a cast piston). Why - because this is the only way to achieve the clearances needed to maximise the power output. A forged piston may perform better when working outside the service limits, but this should not be an attraction for a racer."
I was told about different rates of expansion and distortion between the two and that cast pistons are better for air cooled and forged better for liquid cooled engines
Turn On, Tune In, Cop out!
Consider the source - they make cast pistons therefore they believe cast pistons are superior.
It's another one of those arguments that has no clear winner. In theory it's debatable, in practice it's just not overwhelmingly proven one way or another. It makes all the difference in the world who casts the pistons though - that's for sure. Some are pure sheet.
It's another one of those arguments that has no clear winner. In theory it's debatable, in practice it's just not overwhelmingly proven one way or another. It makes all the difference in the world who casts the pistons though - that's for sure. Some are pure sheet.
Just took a look in the book "Two stroke performance tuning" by A. Graham bell.
For anyone who has a copy this quote is from page 205.
" The biggest improvement to be made to pistons came when the means were discovered for adding large quantities of silicon to the aluminium alloy. This has reduced the piston expansion rate drastically, minimising the incidence of seizure.
Silicon also imparts more strength to aluminium at high temperatures and increases wear resistance.
Quality pistons for competition use generally contain 18-22% silicon. Unfortunately, there are pistons being sold that do not contain very much silicon at all, even though the manufacturers claim they are racing pistons. This occurs because high silicon content pistons are hard to manufacture and expensive to machine."
I'm not looking to put any products down but it does seem generally accepted that this is true?
For anyone who has a copy this quote is from page 205.
" The biggest improvement to be made to pistons came when the means were discovered for adding large quantities of silicon to the aluminium alloy. This has reduced the piston expansion rate drastically, minimising the incidence of seizure.
Silicon also imparts more strength to aluminium at high temperatures and increases wear resistance.
Quality pistons for competition use generally contain 18-22% silicon. Unfortunately, there are pistons being sold that do not contain very much silicon at all, even though the manufacturers claim they are racing pistons. This occurs because high silicon content pistons are hard to manufacture and expensive to machine."
I'm not looking to put any products down but it does seem generally accepted that this is true?