RB26 Tomei Piston Ring Gap

[John28]

Hi guys,

 

i built up my RB26 engine with with tomei pistons (86,5mm). The supplier manual says piston ring gab Ring 1 and 2   0,18-0,35mm.  It seems very tigt in compare with other pistons (wössner, CP etc). My engine workshop adjust 0,25mm for the rings, that makes me a litte uncertain. Does anyone have experience with the tomei piston rings?

Piston to wall clearance is 0,055, pursunat to supplier manual!!!

  Sorry for my bad  english 🤯

 

My aim 550-600hp. 

 

[joshuaho96]

OEM piston ring end gap is 0.24 to 0.34 mm. Japanese RB parts tend to be more street oriented so they try to target clearances closer to OEM. Piston to wall clearance on OEM pistons is 0.035 to 0.055 mm. Keep in mind that too much ring gap will cause issues with blowby and thus oil control. On the other hand too little gap will cause the ends to connect and cause the engine to seize. I would contact Tomei directly and see what they recommend to target for your application.