ring gaps on pistons moved

grumpyvette

Administrator
Staff member
"HEY GRUMPYVETTE?
When I took the 454 apart the ring gaps were not indexed weren't where I put 'em. did I do something wrong?"



thats not at all unusually,in a correctly honed bore, thats truely round/concentric, as the piston rings in most engines tend to slowly rotate in the piston grooves as the engine runs, in fact it tends too reduce ring and bore wear,rates so its hardly a bad thing
"in some engines more than others, some engines are more prone to this and the thicker and stiffer the cylinder walls are, and the more consistent the bores hone job was and the smoother the bore, the less likely it will occur , but its very common to have ring gaps rotate from the original location" UNLESS pinned

http://www.kb-silvolite.com/article.php ... ead&A_id=8

viewtopic.php?f=53&t=5454&p=16301&hilit=groove+rings#p16301
Rotation

When the engine operates, it causes vibrations in the cylinder bores.This vibration results in piston rocking, which creates friction generated by uneven ring contact around the circumference of the ring grooves. The rings then spin while moving up and down the length of the cylinder.




91.jpg
,
92.jpg

due to the surface hone marks and the ring surface friction,and other factors but generally they stay semi close to being indexed to each other so the gaps don,t line up

heres how they are normally indexed but they do tend to rotate slowly in the piston ring grooves and thats not only normal but expected to some extent
RingEndGapsOrientation01.jpg

ringindex.gif


rfig2.gif



READ THE LINKED INFO


http://www.sacskyranch.com/piston_ring_rotation.htm

http://www.pbase.com/stealthfti/image/38397562

http://www.circletrack.com/techarticles ... index.html

http://www.enginebuildermag.com/Article ... _know.aspx

http://www.costex.com/Library/articles/IT05.pdf

http://www.enginebuildermag.com/article ... blems.aspx
 
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