Ring gap spacing...

[motogman]

I have recieved various recommendations on ring gap spacing and while thinking about it wanted to get the greater minds here giving input.

It would seem that the purpose of orientating the ring gap is to maximize the leak path to get best compression -  if this is the case, then I would I would think the orientation would be 180 degrees from one to the next.

It would also seem that the gap should be in the direction of the piston pin.  If the gap is 90 degrees from the pin it would be in the position that would get the most loading due to the inertial and firing forces on the piston.  This would seem to be less desirable than having a uniform section and continous ring surface in this area.

So it would seem the gaps should be 180 degrees from each other aligned with the pin?  What do you say?

[oldbike54]

 Rings rotate in the bore , just don't line the gaps up .

 Dusty

[Idontwantapickle]

You're logic is sound gman.

 

[lucky phil]

I have recieved various recommendations on ring gap spacing and while thinking about it wanted to get the greater minds here giving input.

It would seem that the purpose of orientating the ring gap is to maximize the leak path to get best compression -  if this is the case, then I would I would think the orientation would be 180 degrees from one to the next.

It would also seem that the gap should be in the direction of the piston pin.  If the gap is 90 degrees from the pin it would be in the position that would get the most loading due to the inertial and firing forces on the piston.  This would seem to be less desirable than having a uniform section and continous ring surface in this area.

So it would seem the gaps should be 180 degrees from each other aligned with the pin?  What do you say?

The rings will rotate around the piston anyway so dont stress too much. Generally you set them around 60 deg apart on the non thrust side of the bore.

Ciao

[motogman]

Rings rotate in the bore , just don't line the gaps up .

 Dusty

I wondered about that.  given this to be true....  do they rotate to any prefered position?

[oldbike54]

I wondered about that.  given this to be true....  do they rotate to any prefered position?

 They will usually rotate until they begin to bed in . Kind of difficult to know where they will end up . I did have a Triumph motor rotate its rings until both gaps were lined up perfectly with each other , after very carefully placing the gaps to the rear 60 degrees apart . Sigh .

 Dusty

[motogman]

Do they stop rotating after they are bedded in?

Sounds like something a little JBWeld can fix...   hee hee

[oldbike54]

Do they stop rotating after they are bedded in?

Sounds like something a little JBWeld can fix...   hee hee

 Hopefully , yes . Some pistons have buttons in the ring grooves that prevent the rings from spinning, mostly 2 strokes .

 Dusty

[lucky phil]

Do they stop rotating after they are bedded in?

No. In some race engines the rotation is so pronounced it wears the ring lands quite badly.
That's also one of the reasons why you also check ring to land gap on reused pistons.   

Ciao

[Chuck in Indiana]

The rings will rotate around the piston anyway so dont stress too much. Generally you set them around 60 deg apart on the non thrust side of the bore.

Ciao

 :1:

[Mike Tashjian]

Never thought the rings would rotate around much, so I learned something new.  The pinned two stroke rings are held in place so the open ends don't get caught in the ports.  Mike

[normzone]

Wow, thank you gentlemen for the contribution to my education.

 

[Chipmaker]

Some 4 strokes also had pined rings.The Hudson Hornet flat head six for one

[lucky phil]

Some 4 strokes also had pined rings.The Hudson Hornet flat head six for one

Interesting, probably had 4 ring pistons as well?
Ciao

[Chipmaker]

I dont remimber how many rings thay had.Its been to many years since I worked on one and I am to lazy to go to the shop to check the manual,Yep still got the manual.
  I do remember how mutch of a pain thay were to work on.The ring pins were all in a row,ring gaps were all in a line.When the engine was worn enough for new rings, the cylinders had a ridge where the ring gaps were running up and down.The ridge was a pain to remove also the ring grooves in the pistons were hard to clean do to the pins being in them.