.01 Ring with Standard Piston

[Diseazd]

Are you kidding me? You want to install .010 inches ( .25 mm) oversized rings on a standard piston? Never heard of anyone doing that, but am sure that would probably be a disaster! Get the cylinders honed at a machine shop, install standard rings on your cleaned up standard pistons and your gaps will be correct. IMHO

Edited January 14, 2021 by Diseazd

[Trnelson]

I know they would have to be filed down to get the right gap.  I've read that this used to be common practice on older engines.  Obviously I have zero experience with it but it seems to me that if the target gap is .030 - .043 and as it stands now with new standard size rings set in the bore my gap range is .48 to .53  The oversized rings are .25mm larger then it would require filing off .07-.02 to get to the .030 gap.  I would want to cheat that up to probably .035 to be safe on the bottom end of the stroke.

Current gap= .53 with standard ring, .28 with a .25 larger ring so file off .07 to get .030

I am assuming that the .25mm oversized ring is the same thickness as standard and will fit in the standard piston

Quote from an AACA forum:

"Typically every cylinder is bored because it incresases displacement, and possibly piston weight. Not always. It was not uncommon in the old days to fix one cylinder by overboring. A one-cylinder fix today usually involves sleeving the really bad cylinder to match the good ones.

.010, .020, etc are piston and bore oversizes. An .020 piston ring goes on an .020 larger piston in an .020 larger bore.

If a bore has wear it is possible to put in larger rings to compensate for wear, to some small extent. These are called "File-Fit" rings. They are made just a little too long and you file the ends to get the ring gap where you want it. They can be used in new engines when trying to get the ring gaps absolutely perfect (for racing, etc.). In old engines they can be used to make the wear situation a little less bad.

The limitation is that worn bores have taper, and if a ring gap closes when hot, the ring breaks and it destroys everything in sight.

You have to set the gap at the bottom of the bore (the least worn part), because the gap is tightest there. The part that matters most to the ring's function though is the top, and the top is more worn. No matter what you do the ring gap at the top of the bore will be too loose, it will just be a little less loose than if you had just put standard rings in. It helps, but is no substitute for a rebore and new pistons.

People used to also knurl pistons to compensate for piston skirt and bore wear, to keep them from slapping and making noise.

For the most part, nobody does this stuff anymore."

 

I'm probably way overthinking this and will spend a lot of time for very little gain...  Such is my life 🙃

Edited January 14, 2021 by Trnelson

[Trnelson]

5 hours ago, siteunseen said:

Okay, you got me now.

If Anniston is considered huge you are isolated.

Yea right! FYI if you don't already know Anniston is home to the best pizza place in the southeast.

[siteunseen]

38 minutes ago, Trnelson said:

Yea right! FYI if you don't already know Anniston is home to the best pizza place in the southeast.

The guy I work for here in Gadsden is from Anniston. His family has had bbq restaurants since the 60s. The Goal Post was the first now they have Betty's BBQ. I work at Pruetts BBQ. Not familiar with the pizza shop you're speaking of because I always eat for free at Betty's.

I'm 40 minutes north, up hwy 431. What's the name of the pie slingers place?

[Zed Head]

16 hours ago, Trnelson said:

 So with the new standard rings installed to a depth of 2.5” I’m getting anywhere from .48mm to .53mm end gap. Monroe’s Manual says anything over .43mm get new rings.

He said the new rings, unmodified, have a gap that is too big.  Honing won't make the bore smaller, and you can't file a ring end to make it smaller.  Cut it twice and it's still too small applies here also.

I wonder if the pistons aren't already one size over.  There are no piston measurements here.  You kind of just need to get all of the measurements and figure out the best combination.  For just a few thousand miles a year, you could probably just hone and put the big gap rings in and be fine.

3 hours ago, Diseazd said:

Are you kidding me? You want to install .010 inches ( .25 mm) oversized rings on a standard piston? Never heard of anyone doing that, but am sure that would probably be a disaster! Get the cylinders honed at a machine shop, install standard rings on your cleaned up standard pistons and your gaps will be correct. IMHO

 

[Trnelson]

26 minutes ago, siteunseen said:

The guy I work for here in Gadsden is from Anniston. His family has had bbq restaurants since the 60s. The Goal Post was the first now they have Betty's BBQ. I work at Pruetts BBQ. Not familiar with the pizza shop you're speaking of because I always eat for free at Betty's.

I'm 40 minutes north, up hwy 431. What's the name of the pie slingers place?

I remember The Goal Post, used to have the neon football flashing through the uprights!  Mata's Pizza not too far down Quintard from where the Goal Post used to be. Try it sometime, I'll be willing to bet you will love it.

[siteunseen]

We got that neon goal post and it is now at Betty's!

You are my friend now, like family. It's nice to have that connection.

Cliff

[siteunseen]

https://www.wbrc.com/story/24464868/anniston-goal-post-neon-sign-to-be-restored-displayed-at-another-restaurant/

[Trnelson]

1 hour ago, Zed Head said:

He said the new rings, unmodified, have a gap that is too big.  Honing won't make the bore smaller, and you can't file a ring end to make it smaller.  Cut it twice and it's still too small applies here also.

I wonder if the pistons aren't already one size over.  There are no piston measurements here.  You kind of just need to get all of the measurements and figure out the best combination.  For just a few thousand miles a year, you could probably just hone and put the big gap rings in and be fine.

 

I will re-check the piston size this evening but if memory serves me they are 83mm

I must be missing something but it seems to me that if you file both ends of a ring equally you could make it smaller when compressed.  I'm looking at a manual ring filing tool on Amazon and it seems easy enough to use, just take little bites and keep checking

[Zed Head]

You said the gap was too big when using new unmodified standard rings.  Honing won't make the gap smaller, it will make it bigger.  I was replying to Diseazd's comment.  He said to just hone and use standard parts, but you already tried standard parts.  That was your original point.

[Trnelson]

38 minutes ago, siteunseen said:

https://www.wbrc.com/story/24464868/anniston-goal-post-neon-sign-to-be-restored-displayed-at-another-restaurant/

Damn that brings back memories.  We would travel from KY to AL every Christmas, when I saw that I knew we were close to Grannie's house!  Glad its still glowing strong

[Trnelson]

4 minutes ago, Zed Head said:

You said the gap was too big when using new unmodified standard rings.  Honing won't make the gap smaller, it will make it bigger.  I was replying to Diseazd's comment.  He said to just hone and use standard parts, but you already tried standard parts.  That was your original point.

Ah, sorry  I got all caught up talking about restaurants in Central AL and thought you were replying to me.  More measurements coming soon and as far as your question regarding oval shaped bores, they don't seem to be oval as the gap is consistent regardless of orientation within the bore.