Hello I am working on my 292 and after checking the end gap on my Hasting piston rings I find the end gap a little to big. The 292 with the 3.75 cylinder was bored out to 3.79 (40 over ) . I am multiplying .004 x 3.79 for the top ring and coming up with .01516 so I assume my gap should be .015 but what I have with the ring square in the cylinder is .025 ten thousands bigger than it should be . The lower ring I am going with 3.79 x .005 which is 01895 roughly .019 the actual gap with the ring in the cylinder is .021 just about two thousands bigger . Am I ok with the end gap or should I get another set of rings I could live with the bottom number but I am wondering about the top being 10 more than it should be. Maybe someone can advise a ring set that would be closer to specs. Thanks

Did you actually mean 25 ten thousandths over size?  That's .00025.  I wouldn't hesitate to use them that way.  What I don't understand is why they specify more clearance for the second ring.  The top ring sees more heat, I have always given the top ring more clearance than the second ring.

John - "The Hoosier Hurricane"

The gap should be .015 according to manufacturers specs when the ring is placed in the bore and checked with the feeler gauge the gap is .025 but it should be fifteen thousands . The gap is ten thousands to big according Hastings specs

that is a lot.most i have seen on a 292 was .018.

While 0.025” is a bit on the large side for the top ring end gap in your particular application, I wouldn’t have a particular problem with it for a street engine.  I have experimented with as much as 0.065” top ring gaps and the engine ran just fine.  It just ran better though with tighter top ring end gaps.  Second ring end gaps can be tighter or looser than the top ring gaps and which direction you choose simply depends upon who you talk to.  Sealed Power did some extensive research into the second ring end gaps several years ago and found a significant horsepower increase on performance engines where the second ring gap was larger than the top ring end gaps.  There are limits to both the top and ring end gaps at which point performance numbers do fall off.

I do question why you are getting that large a gap though assuming your cylinder bores are ‘on the money’ in regards to sizing.  Double check your cylinder bores with a micrometer and insure that the bores are indeed 3.790".  If a fresh bore, then the gaps will be the same the length of the bore.  If the bores are worn, then expect a larger ring end gap closer to the top than further down in the bore.  With all that being said, piston rings are manufactured for specific cylinder bore sizes and if your bores are just 0.003” larger than the suggested ring bore, then the ring end gaps will be 0.010” larger by default.  If the rings are for another application with a slightly different bore size, likewise the ring end gaps will vary.

Here’s the link to a recent discussion on ring end gaps.
http://forums.y-blocksforever.com/FindPost147978.aspx

Lorena, Texas (South of Waco)

Ted, thank you for your input , I really respect your knowledge. This is a complete rebuild ,the engine has been cleaned and bored dead on to 3.79 I have checked each cylinder a few times with a bore gauge. I thought I could get by but I rather not be on the high side of the specs. I am wondering if the wrong rings were put in the box because according to Hastings own specs the gap is to big.