Really weird bore wear - I'm stumped

[carmakerevive]

Would it be for protection against bore lip damage from detonation?

[modok]

Its tough to believe that's really necessary in a diesel application because I've seen a lot of those with a ton of miles and really very little cylinder wall wear. Assuming a regular cast iron block was used in the 5.9 Cummins, 7.3 Ford etc.

Unless it is all about the reduction of emissions. Maybe to allow a lighter ring package instead of the keystone type of top ring..

I'd not mind if they did it to ford 6.0 and 6.4, I'd not have as much work but then again I don't particularly enjoy working on those either. I'm not happy and customers are not happy. With the cummins everybody is happy.
Ring and cylinder wear has as much as doubled in recent engines with common rail and a lot of emissions mods compared how it was with mechanical injection. The duramax block and rings are AMAZING.....BUT.....you pay for it, 2-3x more fr every part.

[Zmechanic]

So someone is actually doing laser honing. I thought it was just one of my pipe dream ideas... Makes sense Gehring is doing it. They also do sintered
metal powder (spray welding) cylinder coating machines too.

Edit: WAIT NM, Heller does the cylinder coating machine. Oh well..

[Dan Timberlake]

http://image.trucktrend.com/f/29386607+ ... linder.jpg

Photo 7/29 | The top 2 inches of the cylinders are induction-hardened to radically reduce cylinder-wall wear caused by the piston rings. These leopard-spot-like markings, caused by the hardening process, are not visible on new blocks, as the final honing process erases them.

[GARY C]

https://www.gehring.de/sites/default/fi ... -en-ww.pdf Looks a lot like this.

Just when you think you've see it all!

[GARY C]

Its tough to believe that's really necessary in a diesel application because I've seen a lot of those with a ton of miles and really very little cylinder wall wear. Assuming a regular cast iron block was used in the 5.9 Cummins, 7.3 Ford etc.

Unless it is all about the reduction of emissions. Maybe to allow a lighter ring package instead of the keystone type of top ring..

I'd not mind if they did it to ford 6.0 and 6.4, I'd not have as much work but then again I don't particularly enjoy working on those either. I'm not happy and customers are not happy. With the cummins everybody is happy.
Ring and cylinder wear has as much as doubled in recent engines with common rail and a lot of emissions mods compared how it was with mechanical injection. The duramax block and rings are AMAZING.....BUT.....you pay for it, 2-3x more fr every part.

Why Ford ever dropped the 7.3 is beyond me!

[roc]

Its tough to believe that's really necessary in a diesel application because I've seen a lot of those with a ton of miles and really very little cylinder wall wear. Assuming a regular cast iron block was used in the 5.9 Cummins, 7.3 Ford etc.

Unless it is all about the reduction of emissions. Maybe to allow a lighter ring package instead of the keystone type of top ring..

I'd not mind if they did it to ford 6.0 and 6.4, I'd not have as much work but then again I don't particularly enjoy working on those either. I'm not happy and customers are not happy. With the cummins everybody is happy.
Ring and cylinder wear has as much as doubled in recent engines with common rail and a lot of emissions mods compared how it was with mechanical injection. The duramax block and rings are AMAZING.....BUT.....you pay for it, 2-3x more fr every part.

Why Ford ever dropped the 7.3 is beyond me!

The good ol' 7.3 would not meet current emission standards without a lot of rework.

[GARY C]

I see. It just seems like it would be less cost to perfect it than to produce a completely knew engine.

[roc]

I see. It just seems like it would be less cost to perfect it than to produce a completely knew engine.

That is a natural thinking, but newer engines are designed to cost less to be manufactured (and meet more stringent emission levels). Bean counters are always on the steering wheel, not engineers.

[peejay]

I see. It just seems like it would be less cost to perfect it than to produce a completely knew engine.

Not when the inadequacies are inherent to the design. Time marches on, we learn better ways of manufacturing, we get new technologies to put into the engines, we get better materials. The 7.3 was a fine engine for its time but so was the 300 straight six.

[GARY C]

I see. It just seems like it would be less cost to perfect it than to produce a completely knew engine.

Not when the inadequacies are inherent to the design. Time marches on, we learn better ways of manufacturing, we get new technologies to put into the engines, we get better materials. The 7.3 was a fine engine for its time but so was the 300 straight six.

Has cummins had to redesign theirs over the years?

[roc]

I see. It just seems like it would be less cost to perfect it than to produce a completely knew engine.

Not when the inadequacies are inherent to the design. Time marches on, we learn better ways of manufacturing, we get new technologies to put into the engines, we get better materials. The 7.3 was a fine engine for its time but so was the 300 straight six.

Has Cummins had to redesign theirs over the years?

C'mon man, Cummins is Cummins . The venerable ISB has been receiving continuous improvements since launched in '98. But some engines were retired for the same reason (e.g.: L10, N14, ISM11, ...). By the way, they're launching a new HD engine, the X12, I've heard good things about it.

[GARY C]

I'm just asking, the only thing I know about Diesels is you don't want to put unleaded in them and it will tow your trailer house even if it doesn't have wheels. Oh and they require more maintenance and I'm lazy so I stuck with a gas powered truck.

[sanfordandson]

Oh and they require more maintenance

That would be incorrect.

[sanfordandson]

Its tough to believe that's really necessary in a diesel application because I've seen a lot of those with a ton of miles and really very little cylinder wall wear. Assuming a regular cast iron block was used in the 5.9 Cummins, 7.3 Ford etc.

Unless it is all about the reduction of emissions. Maybe to allow a lighter ring package instead of the keystone type of top ring..

Its simply for wear. The duramax block is gray iron and the induction hardening prevents wear in that area.