Ductile Split Groove Piston Rings

[Grande Dog]

Howdy,
There were some questions in another thread about these, and I had side tracked the other thread too much already.
People have seen the little video clip of taking a piston ring, and twisting it 90 degrees, The ring didn't break because it is ductile. Way back when I first started to dabble with aftermarket products, I went on a couple trips over yonder and talked to some very interesting, and intelligent individuals.
One of the most interesting was Lee Ho Chia. He had worked for Toyota, and Honda Racing before he retired and started his own business back in his homeland of Taiwan. When he started in on ductile rings, I'll have to admit my brain didn't want anything to do with that thought. As I listened, it didn't take very long realize his depth of knowledge on the subject was awesome. Every time he paused to see if I was following his drift, I was so engaged I could only give a nod, and maybe a involuntary grunt.
We did considerable testing with these rings and, they performed as described. As far as I'm concerned, these rings have every advantage over conventional rings except for one, that being longevity. We chose to do our testing with firewood cutters that were putting food on the table with there saws. Homeowners are tough on there equipment but, they do the kind of hours we were looking for. Timber fallers around here put some hours on their equipment but, they treat their stuff to well (premium fuels, and oils plus regular maintenance). So with our test subjects, the rings were giving about 400-600 hours before the rings started losing their snuff. The grooves in the rings were still there but, they become more of a line rather than a groove. These tests were done with high quality petroleum based mix, and regular unleaded. I personally know of some saws around here that are on synthetic mix that have many more hours on them but, have lost any kind of documented time sheets. I figured with an approximate life span of 500hours, a guy would be in it around, or by then just to clean the carbon out.
I think we were on the AS when it happened but, we did have a shipment come through with non-ductile rings, and the failures were off the hook. I believe that was back in about ought 7. It was I financial fiasco, and a real live learnin' lesson. We've been trying to live that down ever since.
Regards
Gregg

 

[husky01]

I can tell already, this will be one of those 100+ page threads:msp_thumbsup:

 

[zogger]

Never seen em. Who uses them? Aftermarket around here seems to be more or less a consensus to use Caber rings, which are they?

OK, what are the advantages of these ductile rings over cast? Even if they dont last as long?

 

[Grande Dog]

Howdy,
We sell these rings under the NWP brand. They can be bought in pairs, or they come with all of our NWP piston kits, and NWP Big Bore & Standard Bore kits.
Some of the advantages are that you'll never break one. Having less ring in contact with the cylinder means less friction. All kinds of good things come with less friction, like less heat, faster acceleration, less wear on the cylinder etc... .
Like I mentioned, these rings come from the racing world. Longevity wasn't a concern as long as they got you to the finish line as fast as possible. We wouldn't have gone with them if they couldn't have made it to the 500 hour mark under normal to heavy work conditions.
Regards
Gregg

 

[ROWDY]

Ok...It took me awhile to know what your talking about. Those rings have been in use in jap cars for awhile now. The rings don't compress to the cylinder wall as tight as a cast ring and their for, less stress and ware on the combustion chamber. I never knew it was in chainsaws now.

 

[ckelp]

i've had zero failures with your rings,
i have rings in a 262 the guy that runs it is a modern day version of Lennie Small. he beats the tar out of that saw cheapest oil lets it ride in the dump trailer..
and the still going strong two years later

 

[zogger]

Howdy,
We sell these rings under the NWP brand. They can be bought in pairs, or they come with all of our NWP piston kits, and NWP Big Bore & Standard Bore kits.
Some of the advantages are that you'll never break one. Having less ring in contact with the cylinder means less friction. All kinds of good things come with less friction, like less heat, faster acceleration, less wear on the cylinder etc... .
Like I mentioned, these rings come from the racing world. Longevity wasn't a concern as long as they got you to the finish line as fast as possible. We wouldn't have gone with them if they couldn't have made it to the 500 hour mark under normal to heavy work conditions.
Regards
Gregg

Thanks man, just wasnt familiar with these.

 

[67L36Driver]

I think I know what ductile iron is.

Define 'split groove'..................................................................................Yah lost me.:confused2:

 

[nmurph]

I think I know what ductile iron is.

Define 'split groove'..................................................................................Yah lost me.:confused2:

The ring has a small groove cut around the circumferance of ring and into the surface of the ring that mates with the cylinder wall.

 

[Chris-PA]

If one had a cylinder wall that was no longer as uniformly round as it used to be, would these be a benefit?

 

[MCW]

If one had a cylinder wall that was no longer as uniformly round as it used to be, would these be a benefit?

I've seen a few AM kits where there have been imperfections in the Nikasil plating and they'll wear down to this groove in no time flat. In a perfect cylinder these rings are OK but my experience is that you'll get more hours out of solid style rings like Cabers.
There are however ductile split groove piston rings and then there are ductile split groove piston rings. The quality of the ring is far more important than the design.