What kind of Aluminum are gas engine pistons made of, would it be just standard 6061 Aluminum? I have an old Pioneer chainsaw engine that blown out a piston, but the piston is no longer availble to buy. I'm going to machine a new one myself, just need to know what kind of Aluminum to use.

they are typically a silicon aluminum . which is harder than 6061- you may want to speak with someone who has made their own engines-to see which of the commonly available aluminums will work

there is a place around here that makes billet pistons for 2-stroke motorcycles/quads. They use 4032

Aviator,
You may be able to fin a ready made subsitute from another model saw. Check out this site. These guys rebuild old saws every day.


Dave

http://www.acresinternet.com/cscc.ns...9?OpenDocument

Use 7075 T6 and you will not be dissappointed.

Bar-stock pistons expand a lot more than cast silicon-aluminum so it will have to be very loose in the bore when cold. The wrist pin holes may also need bushings for long life.

The piston is a tapered elliptical shape. Not many know how to cam grind a tapered elliptical shape?

Bill
The piston is a tapered elliptical shape. Not many know how to cam grind a tapered elliptical shape?

Bill

Try this link for alloy information.

http://www.stealth316.com/2-pistonguide.htm

Try 380 or 390 series aluminum alloy. 17-19% silicon for 390..., 7.5-9.5% for standard 380 alloy material.

Hypereutectic 390 refers to a unique aluminum piston alloy that contains dissolved and free silicon. The material can be T6 heat treated to high strength and stiffness. Non-heat treated 390 hypereutectic alloy aluminum has slightly less strength than conventionally cast F-132 aluminum. You can machine it and use it...

Remember the K&B .65 Sportster engines that used no crank shaft bushings or cylinder liners...Smiles