29. September 2021, 5:06
I got this question via email, a 477 customer asks:
I have measured the piston and it has a smaller diameter at the top when compared to the bottom - is this normal or a defect?
It is the design - pistons are much hotter at the top when in use - and in this region expand more. In particular forged pistons do that which lead to multiple piston failures during our development time because the boring company had not calculated the greater expansion of a forged piston vs. a cast one. This picture may help to illustrate:
The outer line delineates the deformation when hot.
I got this question via email, a 477 customer asks:
I have measured the piston and it has a smaller diameter at the top when compared to the bottom - is this normal or a defect?
It is the design - pistons are much hotter at the top when in use - and in this region expand more. In particular forged pistons do that which lead to multiple piston failures during our development time because the boring company had not calculated the greater expansion of a forged piston vs. a cast one. This picture may help to illustrate:
The outer line delineates the deformation when hot.