Galloway N.T.S.

[maskell]

G day Pat,
Piston does look good and like you I learn so much from these pages.
As the engine is oiled from a drip oiler the small groove is a way to get oil around all of the piston and also into the gudgeon pin through the tapered hole in the con rod under the hole in the piston.
Looks like a nice piece of cast, was it part of something else (left overs) or a special purchase?

Lance

 

[maskell]

Pat,
I was told that sash weights from older windows were often used for a supply of cast. My friend turned up with a weight as he was also told the same. We were going to make a small piston, NEVER again, it must have been the left overs from the foundry and was very poor quality, it even had hairline cracks right into the centre, just rubbish in this case.
I did make a bore out of an old clutch master cylinder though and it worked well but most times if you buy a little of a good product it is a lot nicer to machine and has a better finish.
Its a good feeling getting it right first time. (happens now and then)
Lance