piston ring options

hi what other options other then cast iron rings are there for a cast iron cylinder/piston combonation, i could make the rings but dont want to get in to that to be fair so what else could i use

mike cheers

hi mike,

for cast iron cylinders and pistons the ideal piston ring material is cast iron piston rings. having said that one of my locos has the above combination with square graphite asbestos packing and is still perfect after 11 years hard work. if you can machine cast iron pistons and cylinders accurately then making cast iron piston rings isnt that difficult and it has been described in ME many many times. i prefer the Prof D. H. Chaddock method rather than Tubal Cain's method. doesnt take long to make a suitable mandrel. if you can get meehanite cast iron then you will make a very fine and easy job of it.

im sure others will have their own views.

cheers,

julian

There are lots of places that supply cast iron piston rings. I need 1.75" rings for my engine and found a company in Australia that can supply them for $12 each. Hardly worth making my own. Do a search to see if you can find someone near you.

Paul.

CI rings will also be a bit more forgiving of your cylinder finish, for graphite yarn you would almost certainly need to lap the surface so it does not abraid the packing.

Rings are not too hard to make but as paul says they can be bought from several of the ME suppliers such as Stuarts, Reeves, Blackgates.

J

I made the rings for a Stuart Turner S9 from cast iron recovered from a car brake disc, nice metal to work with.

Ian S C

Might be worth looking at 50cc moped rings, most sizes from 26mm dia up here,

http://www.mopedland.ukfsn.org/atozring/#stock

currently making some now just having a little break

They all need a little break

It may be worth waiting until you have machined the cylinder then you can make the ring to suit if its a bit above or below bore.

J

Hi Mike

I made cast iron piston rings for my Simplex loco which has cast iron cylinders and pistons, these were made from centrifugal cast iron (meehanite) . The dimensions being 1/16 "thk. x 3/32 "wide x O/D ( Cylinder Bore +0.005". I did not do anything clever to hold these in a fixture for final machining of the diameter. I just turned them 0.005" oversize on the O/D, split them through by cutting from the inside and after springing them onto the piston this gave sufficient spring in them to fit snug in the bore.These soon bedded in, the loco has been running for 37 years with no blow past the pistons and runs very freely having done a lot of work over the years.I think cast iron rings are the best option in cast iron cylinders. This method of manufacture may not be suitable for I/C engines but works O.K. for steam locos. I hope my experience will be of help to you.

Cheers

Henry

I use the same method as Gray but split the rings in a different way, the end cutters are applied to the top & bottom edge and squeezed to give a nice clean break. Then heat with something wedges into the gap.

J