Piston ring gaps

[worked ssv]

Thanks guys I'll see how we go

 

[Immortality]

It also depends on what the engine is been used for, blown or nitrous engines would run slightly larger rings gaps.

And just to be a little different, I see a lot of the engine builders are running the 2nd ring with a slightly larger gap than the first.

 

[383 hatch]

Blown or nitrous engines would run slightly larger rings gaps.

Make 'em loose, make 'em live...

 

[Wombles]

Immortality, I think my rings specified the other way around.

 

[EYY]

Forged pistons require more piston to cylinder clearance too. The extra materials taken off the cylinders when boring would give you the larger ring gap.

So many different combinations that all require different tolerances etc etc. seems like the wise thing to do is follow the instructions

 

[Immortality]

Immortality, I think my rings specified the other way around.

Yep, it's the traditional way.

Forged pistons require more piston to cylinder clearance too. The extra materials taken off the cylinders when boring would give you the larger ring gap.

So many different combinations that all require different tolerances etc etc. seems like the wise thing to do is follow the instructions

But who's instructions? Piston manufacturers sometimes give their own instructions to suit ring gaps, i.e

http://www.cp-carrillo.com/LinkClick.aspx?fileticket=Q7LAfTKUjgE=&tabid=74

At the end of the day, follow the ring manufacturers instructions and you should be fine.

 

[delcowizzid]

if they arnt file fit they are probably bigger than required anyway

 

[383 hatch]

Forged pistons require more piston to cylinder clearance too. The extra materials taken off the cylinders when boring would give you the larger ring gap.

So many different combinations that all require different tolerances etc etc. seems like the wise thing to do is follow the instructions

That's when you buy file back rings, so you can set the ring gap exactly.

 

[383 hatch]

https://www.uempistons.com/installation_instructions/kb_installation.pdf

Those are the pistons I used in my Chev, KB say to set the top ring gap larger than the bottom ring (by a fair amount) to allow for the top ring being so close to the top of the piston. Now, if I'd followed the ring manufacturers instructions, I'd have set them both at the usual .004 per inch rule the ring would likely but and pull the top off the piston.

So, in that case I went with the piston instructions. You just need to follow the instructions that make the most sense.

 

[EYY]

That's when you buy file back rings, so you can set the ring gap exactly.

Yeah forgot about that. Highest performance engines I've played with have been 2 strokes where you don't need to worry about anything like that lol.

On another note...I've heard about people using gapless rings.... How do they work?? Always made me wonder how you get them on the piston etc