I tried a search but I just kept finding "use low-tensile rings"

Are moly or plasma-moly low tensile? Planning on a 175-200 shot.

 

It depnds what you mean by "low tension rings". Any modern ring set will be "low tension" by traditional rebuilding or OEM standards. The amount of force the ring exerts against the cylinder wall depends on tangential tension as well as ring thickness and cylinder bore diameter. Conventional oil rings exert pressures in the range of 180 to 240 psi. Low tension rings fall in the 90 to 160 psi range. Low tension rings are thinner and exert less pressure against the cylinder walls. This reduces friction which can increase hp and improve fuel economy.

However, within the context of modern ring sets, there are alsovery thin rings which should be used exclusively for max hp race engines that are rebuilt frequently. What you need for a small nitrous shot is simply a good set of plasma moly rings that fit your pistons properly and are installed correctly in properly honed cylinders. What pistons are you using? The piston manufacturer is usally a good source of ring info. If you want to get fancy, the Speed-Pro Hellfire rings are an excellent but expensive choice. Probably not needed for a relatively small nitrous shot though.

Rich

With properly round cylinders

 

The TRW-L2256F40. Speed Pro .040 FT. On summitracing.com they list 2 rings sets for the pitons. The SLP-E-251K40, moly, or the SLP-R-9343-45, plasma moly. They are both 5/64 thick.
Thanks for the input.

 

Plasma moly.

Rich