Expander Ring part #922715

[Al Harpster]

I've just installed a piston & ring set that includes the Expander Ring, Number 16 on the exploded diagram shown in this post.

I've never installed a piston set with one of these Expander Rings before.

It's quite a trick to get the Expander Ring and the Piston Ring aligned with the anti-rotation boss in the piston groove.

That's done, but the FIT into the cylinder is quite tight.

It makes the ring drag on the cylinder greater than I'm used to.

Yep, there's plenty of ring gap and the piston clearance is on the order of .0025"

But that lower piston ring with the Expander Ring under it really pushes hard against the cylinder wall.

Does anyone have direct experience installing a piston & ring set with the Expander Ring?

[Al Harpster]

Sorry, I meant number 46 on the exploded diagram, not 16

[Dale]

Al,
Several years back I asked Paul about the need for the expander ring. He told me that Harry had advised against using them. Good enough for me!
Dale

[taber hodaka]

I have always used them, I install them wet, lubed by my special, secrete oil. ------------Clarence

[tudor8055]

I have put them in and left them out. From what I have read their purpose is to keep the noise down from piston slap.
I built a model 96 about 5 years ago and left the expander out of it. I have about 40 hours on it, always starts and runs right.

[Al Harpster]

Thanks for the replies.

I left the expander in.

Seems to run fine.