what can cause a ring to break

[DieselPower]

Don't know what engine your working on. You should check your overhaul manual for the exact spec on the ring gap. They can be different for different engines and manufacturers.

 

[cpdtwo]

do not have overhaul manual. its a yanmar gray markey 1500. was thinking about putting sleeves in but hten I do not know if i realy need one. if any thing i would bet that there is too much gap in rings. would that cause it it break? did not ream sleeve befor putting new rings in , just homed them. now tring to see what i should do next.

 

[Sully2]

what would too much be?

These men have told you definalty "right"...AND..a "hone"..IS NOT a "ridge reamer"..no way shape nor form!!
As far as "too much"..you need the rebuild specs on that engine. It will tell you that ring gap should be ".XXX-.YYY"...and you have to fall into that dimension...either buy filinf the gap open..or going to a larger rig to close it down some.

 

[dbdartman]

Measuring ring gaps:

First, you are only concerned with the area of the cylinder where the rings ride, not the ENTIRE length of the cylinder.

Put a ring in the bore, & using the piston as a tool, use the piston head to push the ring about 1" down in the bore (you do this to keep the ring flat in the bore). Measure the ring gap & write this number down.

Now, using the piston again, push the ring half way down the ring travel area. Measure the gap & write this number down.

Now, using the piston head again, push the ring to the bottom of the ring travel area. Measure the ring gap & write this number down.

If all 3 numbers are the same, you are fine. If the numbers change (bottom ring gap is larger than top ring gap), & you haven't measured an area of the cylinder wall where the rings DON'T ride, the cylinder is tapered & must be bored or replaced.

Since the rings stop at the same point on every piston stroke, the cylinder walls wear where the rings ride. At the top & bottom of the ring travel you will find a ridge. The top ridge is easy to remove (that's what a ridge reamer does). The bottom ridge is NOT easy to remove (that, & cylinder taper, are why cylinders get bored). If you didn't remove BOTH ridges, it's not surprising a ring broke. New rings are thicker where they contact the cylinder wall that used rings, so they WILL contact said ridge. If you're lucky, you only broke the ring. If you're unlucky, you also cracked the ring land (the groove in the piston the ring sits in) & that means a new piston.

The typos in this post are creating all kinds of problems!

BTW, rebuilding an engine without a factory service manual, is a crap-shoot at best! Unless you have certain specifications (like ring gaps, & torque specs & sequences) you are GUESSING & I can guarantee failure, sooner or later (& I'll bet sooner). If you don't have time to take a class at a vo-tec school, then find a couple engine rebuild books for beginners. The questions you are asking are really quite basic, & easily answered, but trying to learn this on the internet WILL end up being a lesson in frustration. Not to sound condescending here, but you need more than just "a little knowledge" to rebuild an engine correctly, because as they say, "A little knowledge is a very dangerous thing!" With that said, the BEST advice I can give you is to take the engine to someone that knows what they are doing. If you can find someone that's willing to teach you as they rebuild it, all the better, but I think you're setting yourself up for catastrophic engine failure unless you get a LOT MORE education on basic rebuild procedures.

The last time I rebuilt an engine was over 30 years ago, too, but I was taught, first in Vo-tech school, then by the US Coast Guard. With that knowledge, I'll happily send my engines out to be rebuilt because I don't have the special measuring tools, or clean space, necessary to do a proper job.

 

[Soundguy]

Ether will break rings as well.

Soundguy

 

[normde2001]

do not have overhaul manual. its a yanmar gray markey 1500. was thinking about putting sleeves in but hten I do not know if i realy need one. if any thing i would bet that there is too much gap in rings. would that cause it it break? did not ream sleeve befor putting new rings in , just homed them. now tring to see what i should do next.

You definitely need to buy a service manual and read it.

 

[Sully2]

... With that knowledge, I'll happily send my engines out to be rebuilt because I don't have the special measuring tools, or clean space, necessary to do a proper job.

And unless your in that sort of business...OR have had the "tools" passed down to you from someone..a guy cant afford to BUY THEM to do an engine every 10 or 20 years. Nothing is cheap anymore...

 

[cpdtwo]

service manuels for 1500 yanmar are in Jap. you can use one thats for years before and atfer and get good ideas but not always the right one. as far as having it done it would be more than I paid for the tractor. older engines are easier to repair than newer ones so I know I can do it. I know what tolls to use its just I forgot names. was trained years ago and did rebuild boat motors in the army but that was 40 years ago. Have seen what the kids call training in these schools now and I learned more from tring than they know after school. maybe thats why they work at tire shops and chain repair shops and now we can't getour cars fixed right the first time.

 

[cp1969]

The problem is, though, that there are lots of shops out there masquerading as engine "professionals" who may in fact possess less knowledge of your engine than you do. But they will --gladly-- take your money. They talk the talk but can't walk the walk. Unless you can truly separate the make-believers from the real thing, my opinion is you're better off doing it yourself.

I am in the process right now of trying to straighten out a mess made by a "professional" big block Chevy builder. A friend's 427 was using a quart of oil every 200-400 miles, and said builder diagnosed it as needing complete overhaul. $7k+ later, guess what? It uses a quart every 200-400.

 

[dbdartman]

I am in the process right now of trying to straighten out a mess made by a "professional" big block Chevy builder. A friend's 427 was using a quart of oil every 200-400 miles, and said builder diagnosed it as needing complete overhaul. $7k+ later, guess what? It uses a quart every 200-400.

I've also read that post & my feeling on THAT situation is this: The heads & block have been cut to the degree that the intake no longer seals. As I see it, the "easy" way to fix that is to have the intake milled to match the heads/block, the "proper" way to fix it is to start over with a block & heads that haven't been decked/cut.

On the tractor engine (or any other for that matter), the "rule of thumb" is: If you can feel the ridge with a fingernail, you need a bore or new jugs.

I wish you the best of luck with both engines!

BTW, my brother was a victim of a well known & well respected engine builder in the Mopar world. 3 years & maybe 10K miles after installing a rebuilt 440 & auto trans, both from said builder, the crank shaft had almost 1/4" of end play! The torque converter builder blamed the engine builder, the engine builder just hung up on him when he called, & he ended up having the crank welded & re-cut, then had to spend the long $$$ for ANOTHER trans & converter. He sold that engine a couple years ago (& it was treated to yet ANOTHER rebuild because it was supposed to be 9.2:1 & was in reality maybe 8:1 at best). He now has a 493 (stroked 440) that makes an honest 550 HP & 590 ft/lb at the crank (it was run in on an engine dyno), built at a 1-man shop in Burlington, Vt.