Pro-X piston ring question

[rdsarefun]

So I am finally getting around to replacing my Top end with my Pro-X pistons and modified cylinders from Bill Bune (that I had received late last year). This is for my 75 RD350.  I has 2 rings and a oil expander (assuming this is what the corrugated ring is- does not look like the one in the instructions, stating for 4 stroke only, attempting to upload a pic but phone is temper-mental today)).  I did not receive any instructions and found a generic set online. It was very difficult to see the ring profile edge (to determine what was top and what was second ring) so I measured these with a set of calipers and measured the ring lands within the pistons with a feeler gauge and found that the top is thicker (.059") and the 2nd ring is thinner (.046"), each marked with a "T" so I can install correctly.  My question is that I do not see where the expander is used, assuming it goes behind the top ring due to width being .056" thickness.  can anyone confirm this is where the oil expander goes, behind the top ring or is it not used at all? 

[m in sc]

they typically go under the second ring, most people leave them out. its just an expander ring, not an oil expander ring.

[rdsarefun]

Thanks Mark, i managed to upload some pics and you can see that it looks nothing like the pic in generic instructions.  I made a typo though, the second ring is thicker, wanted to clarify for future reference  Second ring is .059",  top ring is .046"

Thanks, Brian

[rdsarefun]

Fired it up today, engine seems very lethargic as compared to before. Let it warm up 5 minutes, going to retorque cylinder head to 15 ft pounds and then run again, set timing.  Head was modified (squish band),  assuming I need to readjust timing.

[m in sc]

you sure thats right? typically the wider ring (more cross section) is the top ring. the one oyu have labeled as 'top' is thinner to make room for the expander but if its marked that way.. ? weird.

id do a compression check after 2-3 heat cycles see where you are.

[rdsarefun]

Hi Mark,  I made a typo when I took a pic and placed the rings on the instructions.  I have these installed correctly as the ring land on the piston prevents a mismatch.  I kept the expander out.  See below in italics:

I made a typo though, the second ring is thicker, wanted to clarify for future reference  Second ring is .059",  top ring is .046"

[2steve]

I kept the expander out.

And Chuck Quenzler would tell you to do just that.

In fact, the exact quote was, "I forgot to take the expanders out before I shipped. Throw them away!"

[SoCal250]

One of Chuck's recommendations from 2019: "Another tip on Pro-X pistons kits is throw the 2nd ring wavy expander in the trash, don't use it!"