So i started to assemble my b16a block today and got a little stuck on determining my piston ring gap. I did the equation that wiesco provided in the box with my pistons. I came up with .016” for the top compression ring and .017” for the second compression ring. The gap just seems a little tight to me especially at the power i want to make around 400-450. I just want to hear from people and see what others thing of the numbers i came up with. Let me know your setup and what your ring gap is.

 

I normally do .004-.0045 time bore in inches but would fallow what the piston and ring maker says as pistons and rings from brand to brand like different clearances

 

Turbocharging requires greater ring gaps than .004-.0045" per bore inch... those values are recommended for N/A street driven engines. For turbocharging, you want ring gaps at .0055-.0060" per bore inch. It is better to go too big instead of too small... if the rings swell when heated enough to completely close the gap, and the ring ends touch... cylinder wall damage WILL occur.

 

^^ And ringlands too. If the ring gaps are too tight for the application and butt together, they could very well begin to flex, essentially breaking the **** out of some ringlands.

OP: it's good to ask around for what folks may be running, but this is something that your piston manufacturer (or data sheet), your builder/machinist, and you need to decide. This will be based heavily upon your build and use of the vehicle.

 

Since I’m running JE pistons I called JE Import tech support and told them my power goal and they told me what to run. I would advise doing the same

 

I run CP rings And my top ring I gap at .019 and bottom gapped at .024.

Boosting over 20 psi no problems here.