ok i got some srp pistons used and they dont have many miles on them so i was thinking about reuseing the rings so i honed my block and then checked my ring gaps and this is what i got.

Top ring #1 cly 0.009
Second ring #1 cly 0.020
Oil control ring #1 cly 0.022

Top ring #2 cly 0.010
Second ring #2 cly 0.016
Oil control ring #2 cly 0.009

Top ring #3 cly 0.010
Second ring #3 cly 0.013
Oil control ring #3 cly 0.015

Top ring #4 cly 0.011
Second ring #4 cly 0.013
Oil control ring #4 cly 0.020


The books specs are
Top ring 0.008 to 0.0014
Second ring 0.016 to 0.022
oil control ring 0.008 to 0.028


what do you guys think ???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedb20z &raquo;</TD></TR><TR><TD CLASS="quote">ok i got some srp pistons used and they dont have many miles on them so i was thinking about reuseing the rings so i honed my block and then checked my ring gaps and this is what i got.

Top ring #1 cly 0.009
Second ring #1 cly 0.020
Oil control ring #1 cly 0.022

Top ring #2 cly 0.010
Second ring #2 cly 0.016
Oil control ring #2 cly 0.009

Top ring #3 cly 0.010
Second ring #3 cly 0.013
Oil control ring #3 cly 0.015

Top ring #4 cly 0.011
Second ring #4 cly 0.013
Oil control ring #4 cly 0.020


The books specs are
Top ring 0.008 to 0.0014
Second ring 0.016 to 0.022
oil control ring 0.008 to 0.028


what do you guys think ??? </TD></TR></TABLE>

It would be possible to re-use rings if they are in good condition, but maybe not the best idea. On a new bore you want new rings so they can both bed in together, though the used rings may well bed in to a new bore perfectly OK (not a problem with new rings in unhoned kart engines). I'd use new rings just avoid any potential problems.

The ring gaps are very important. If the gap is too small (as all yours are) then when the ring heats up and expands the ends of the ring will 'butt' together, causing the ring to be forced very hard against the bore walls as the ring expands further. This could cause ring / bore / piston damage or even engine seizure.

If you must use these rings, the tight ring gaps will have to be increased, which is typically done with a small fine tooth file, or a ring gapping machine (never used one, only heard about them). Even new rings often need to be 'gapped'.

It's no big deal if the gaps are bigger than spec, even with a very excessive ring gap very little pressure escapes through the gap.

It is very commonly thought that large ring gaps are responsible for low compression, but really it's only because large gaps are often found when compression is low (guilt by association, and incorrect assumption). Many engines will have large gaps bit still exhibit good compression, though due to wear and tear probably not 'as new' compression.

Low compression is actually the result of the ring losing tension, or pressure being unable to get behind the ring due to deposits in the groove, or the ring being 'stuck' in the groove due to deposits. Compression is lost around the entire circumference of the ring, not significantly through the gap unless the gap is very excessive.

 

what do you mean the gaps are too tight the ring gaps are within spec the only one i need to file is the second ring cuz its at 0.013 and the smallest it can be is 0.016. so i dont understand y they wouldnt seat in a new motor if they are still in spec

 

bump

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedb20z &raquo;</TD></TR><TR><TD CLASS="quote">what do you mean the gaps are too tight the ring gaps are within spec the only one i need to file is the second ring cuz its at 0.013 and the smallest it can be is 0.016. so i dont understand y they wouldnt seat in a new motor if they are still in spec </TD></TR></TABLE>

My mistake, I was tired and didn't read the min gap spec, was carelessly assuming that the numbers on the end of the lines in the 'book specs' paragraph were the min clearances. It should have sounded a bit large for a minimum gap, but I'm used to thinking in millimetres not thousandths of an inch.

 

so you still dont think there good enough??

 

I would just get new rings, in the interest of achieving quick/proper ring/cylinder seating.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by inspyral &raquo;</TD></TR><TR><TD CLASS="quote">I would just get new rings, in the interest of achieving quick/proper ring/cylinder seating.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedb20z &raquo;</TD></TR><TR><TD CLASS="quote">so you still dont think there good enough??</TD></TR></TABLE>

I can't really say, it would depend on just how good the 'old' rings actually were. You may well have no issues if you do use them, but you might. Personally I'd use new rings, I wouldn't want to risk having a problem.