Panhard Cylinder Liner Rebore Update 7


A Panhard air cooled twin has tapered bores, but the cylinder casting internal bore is parallel, the liner or sleeve is parallel externally, and all the new old stock liners have been as near as damn it parallel internally. So what is causing the taper?

Here’s the answer


The cylinder casting has variable wall thicknesses,
and is much thicker at the top of the liner than it is at the base of the casting, which means for any given interference fit, the base of the casting will give more than the top, so the liner is squeezed prorate more at the top than the bottom.

Really simple and it’s just physics. By varying the wall thickness to suit the likely temperature gradient, you can achieve tighter running clearances by tapering the bore inwards when cold. If this is combined with modern piston technology & manufacturing a quieter, more powerful air cooled engine will be the result.

blog comments powered by Disqus