Piston Packing

[Peter MaloneyParticipant @petermaloney70994]

[Peter MaloneyParticipant @petermaloney70994]

Hi Guys

How much interference should there be between graphite piston packing and a bore dia of 1.5in? Somewhere I read that 1/32nd in should be ok but it seems a bit excessive when lining up with the bore. I see that Julian Atkins suggests soaking in steam oil to make things easier. When fitted should the piston be moveable with hand pressure?

Thanks

Peter

[norm nortonParticipant @normnorton75434]

Hello Peter

The packing needs to just standing a 'bit' proud, but it will be all over the place with high spots and hollows. Once it is in the bore it should even itself out. Yes you want to be able to 'just' pull and push the piston gripping the piston rod. It will be tight so oil it.

Make a conical adapter (5-10 deg internal taper) that you feed the piston and packing into, then line that up with the cylinder bore to easily slide in. The inside bore of the adapter exit should be the same as the cylinder bore. The taper helps squeeze it all into shape.

Norm

[Peter MaloneyParticipant @petermaloney70994]

Hi Norm

Thanks for your help. Have reduced the interference and am about to make an adaptor if I can find a suitable sized piece of scrap.

Peter

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