I found Dick's assembly notes and the ring gaps are:
Top ring - 0.022 (0.0055/in.)
2nd - 0.020 (0.005/in.)
Oil - 0.028
Weisco says 0.0055/in. for street turbo application, but they want more than the top ring for the second ring. Dick's notes reference 0.0035 for the second ring, so will have to see where he got that. At running temperature I would think that the second ring will be much cooler than the top and thus the gap will be greater than the top ring during operation. Maybe need more study on this.
Another inliner here has an Atlas 4.2L running a turbo for about 4 years now with no issues. His engine was brand new from GM and I don't think it has been opened up at all.
Last edited by J Gregg; 02/20/21 09:02 PM.
