"O" ring

I am making a hit and miss engine from plans and need to order some bits and pieces and while I am doing so I may as well get some of the other bits for it and make the order up.

Anyway to the question for the piston ring it says use a Buno-N "O" ring is this a nitrile one or is there a more suitable one to get.

The second option they say use is a quad seal "x" type ring.

It does state that the engine gets barely warm when running

Edited By Dalboy on 04/05/2023 20:47:36

Viton O rings tend to be less affected by oil and that is what I use on my IC engines both liquid feuled and propane.

Buno-N is the same as nitrile/NBR.

Thank you both for the information I can now order what I need

I think it's "Buna N".

I would go with Viton as it has a higher temperature tating and better oil resistance than nitrile (or Buna N). In addition to perceived engine temperature you have higher temperature at the piston head plus local friction at the O ring to allow for.

Martin

Can I ask where you get yours from as the place I was ordering other things do not do Viton O rings only Nitrile

Edited By Dalboy on 05/05/2023 17:10:38

Try HAYLEY BEARINGS, or PM me with the sizes you need ! Noel

I usually buy metric but I expect the Farmboy wants imperial so Simplybearings should have what you need if you know the BS number just enter that on their site

Thank you both have sent a PM noel