Ring end gap

[big_daddy234]

Hey fellas,

I got my hands on a 365xp that had no compression. turned out to be a broken ring. i ordered a meteor piston with caber ring.

when i put the ring in the bore without the piston the end gap is extremely small, about .0003 thousands. im thinking the small end gap is why the other ring broke, its a hyway cylinder BTW.

piston is about .0010 - .0015 smaller then the bore.

my question is what should the ring end gap be?

Thanks in advance

 

[Big_Wood]

you can file the ends or take a diamond bur to them. i learned my lesson with ring end gaps and the rings provided with golf pistons. it would likely be fine at .005 but i would sooner see .008 especially if you plan to run it hot. with OEM i don't even worry about it. OEM with cabers i don't worry about it but since you have a hyway cylinder and already had a ring crack i'd definitely be sure about what your doing before assembly.

 

[big_daddy234]

you can file the ends or take a diamond bur to them. i learned my lesson with ring end gaps and the rings provided with golf pistons. it would likely be fine at .005 but i would sooner see .008 especially if you plan to run it hot. with OEM i don't even worry about it. OEM with cabers i don't worry about it but since you have a hyway cylinder and already had a ring crack i'd definitely be sure about what your doing before assembly.

Thanks for the reply. Yes with oem i wouldnt worry either but seeing that this cylinder already broke a ring was a red flag.

So are you certain .0008 end gap is ideal?

 

[Big_Wood]

I'm not a ring end gap specialist but last year I had a golf ring collide at the ends because of insufficient end gap. I honestly never worries about it at all until then. I have since used google and it seems .008 is a minimum recomendation from many manufacturers. That said, I have measured a few cabers tighter then that in an OEM bore and ran them with no problems.

 

[Little Al]

Usually quoted for air cooled motors 4 to 8 thou per inch of bore size one point often overlooked is the check for correct fit/seating of the ring end on the retaining pin

 

[ChoppyChoppy]

.008 is 8 thousanths. 0.0008 is 8 tenths..., not even 1 thousanth.

 

[7sleeper]

Why not buy a oem ring, should only be a few bucks for probably much better quality!

7

 

[drf255]

File the gap to .009

I stopped checking on Cabers and OEM jugs. With AM's lack of quality control (why OEM costs more in part) I'd measure twice and cut once, as you are so correct in doing.

 

[troutfisher]

I like to see .010