Ive spent hours researching and cant find an answer. I am rebuilding my turbo D16 project and have decided to go with honda piston rings. I have found that they will fit my wiseco pistons but cant get a definite answer on sizing. I have 75.5 mm pistons so i have an .5 mm overbore. This should translate to a 20 over set of rings but all i can find on a genuine parts site is 25 or 50 over. Do they measure in mm or thousandths of an inch? If they measure in thousandths of an inch will the 25 over work with proper ring gapping. I have called multiple dealers but they are all oblivious. Please help. I am ready to get the beast back on the road. Thank you in advance.

 

why not use the rings that come with the pistons?

 

I should've explained. I took it apart because of detonation to make sure all is good and took the rings off to clean everything and broke a ring on disassembly, i believe that ring had a small nick because it broke using less pressure than taking the other rings off. I researched and found that genuine honda may be best and i trust honda's quality control more than anyone, so i want to use them.

 

Look it up on youtube. Evans tuning made a clip on how to build a B series block. Pretty much the same procedures for a D series.