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Old 05-17-2010, 03:48 PM   #1
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Default Piston ring orientation

I was going to go ahead and clearance my rings but I forgot which ones go where. I figure the two small ones are the top and bottom of the 3rd ring but I don't know which of the other two are the first and second. I have a shiny and a black one and they both have a N on one side. Help me please
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Old 05-17-2010, 04:41 PM   #2
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If I remember correctly(and I might not, its been a long while), the top ring will have a slope on the inside of the ring, and the 2nd ring will be completely flat. I'm assuming the N shows which side is up, but I'd have to be looking at them to tell you for sure.
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Old 05-17-2010, 04:42 PM   #3
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Look carefully at their profiles.

The top one is barrel faced and the 2nd ring is wedge shaped, sometimes with a cutout towards the bottom. The top one is usually shiny and the 2nd black.

The top ring is usually very hard and the 2nd is much softer - remember this when grinding. If these are Supertech pistons the top ring takes 15-18 thou gap, the 2nd, 1.5x bigger. Be sure to dress the edges after you grind them, using a very fine knife sharpening stone.

The 'N' you see means "this way is up".

Don't dunk the whole piston assembly in oil just before putting into the cylinders - use a clean finger and put a thin coat on the skirts, and work a few drops into the ring grooves. Dunking the stuff in oil will get you a lot of oil burning on first start.

You can pre fill the oil galleys with oil by spinning the crank by hand - if you "primed" the oil pump with a coat of assembly lube. The other way to prime the oil pump is to take the allen plug out, pour some thick (e.g. 20w50) oil in and fill er up. If you turn the crank before you put the timing belt in, it will be easy to spin. If you have a VVT head and non stock pistons or non stock cams, be sure none of the valves are at full lift when you do this. Spin until the oil coming up in the head stops bubbling. This way when you start er up you get oil pressure right away.
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Old 05-17-2010, 04:44 PM   #4
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The black one is the one with the slope/step and if the N is on the the step is towards the bottom
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Old 05-17-2010, 04:51 PM   #5
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...Is it a slope or a step? Read what Jason said, and if you still can't figure it out, post pics.
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Old 05-17-2010, 04:56 PM   #6
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Yea the shiny one is harder to press than the black one. I see what you're talking about. Those are the same numbers I came up with when I did my math as well. Thanks alot guys
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Old 05-17-2010, 05:12 PM   #7
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I don't put any oil on the skirts or anything. I spray the piston and the bore with wd40. Allows for quick ring seating.
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Old 05-17-2010, 05:37 PM   #8
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I've heard about people using a very small amount of ATF on the first start up to help ring sealing. Anyone else hear of this?
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Old 05-17-2010, 07:44 PM   #9
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Yes some folks use a light coat of WD40.
Some use a light coat of 2 stroke oil.

Just don't glop on engine oil, bec the burnt oil will end up as carbon in your ring grooves.
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Old 05-17-2010, 08:53 PM   #10
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Assembly lube? I had a huge tub that I had laying around and used it.
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Old 05-17-2010, 09:35 PM   #11
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i use a light coat of 10-30 on the bores, put it on a papertowel and wipe it on. that will be fine. make sure you put the gaps in the correct place. never line the gaps up directly with the skirt or the pin. N faces up. stone the ring gaps if you had to file fit them. a burr can prevent the ring from spining in the groove and scar the bore
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