Forum Discussion
Dave5143 wrote:
Am I seeing things or are those pistons flat as a pancake? What would keep them from wobbling and getting stuck in the cylinder?
A couple of reasons.
1. Because the steel piston is stronger they can place the wrist pin high up into the piston along with a longer connecting rod. This geometry creates less side loads and less friction.
2. Because a steel piston has similar thermal expansion as the engine block, a steel piston can have a tighter fit into the cylinders which requires less piston walls and again less friction
Some benefits of steel pistons: less friction, improved fuel economy, less CO2 emissions, stronger, higher tolerance to heat, high mileage durability, improved cylinder sealing and less oil dilution.- All 3 modern diesels make an insane amount of power compared to just a decade ago. Impressive!
- My "old" 17 Power Stroke has plenty of umph for towing my fifth wheel. I guess having even more would be nice but gotta wonder how much is enough. Anyway, I wonder what kind of mileage the revised engine will get. I had a 2012 GMC single rear wheel Duramax, 2wd, and it would get over 20 mpg solo on occassion and around 11 towing. My next was a 2015 GMC dually, 4wd, and it would average around 17 solo and 10 towing. We recently did a 500 mile solo trip in the Ford and it averaged a little better than 14. It is not unusual for it to get around 9 towing. I know, if you have ask the mileage you can't afford it but still...
Our life's circumstances and the aging process have us slowing down some with our travels. I am curious to see what the new 7.3 gas engine will do. I hope it will be a nice alternative to the expense of a diesel for those of us who mostly use our trucks for things other than towing an rv but still want to at least keep up with the little old ladies and gentlemen driving 55 mph on the interstates. ShinerBock wrote:
FishOnOne wrote:
The biggest news is the steel pistons that will handle some serious cylinder pressures along with a stronger more efficient turbo.
This will be a serious medium duty engine.
Steel pistons are nice and stronger IF they are the same size as the older pistons. If not, then they are just using it to to save weight. That is just like high strength steel frames. Stronger metals can be used to reduce the mass which reduces weight, but it doesn't necessarily meet stringer over all. It just means that you can use less of the stronger metal to achieve the same strength of using more of a lesser metal.
The Mahle forged steel pistons are stronger than cast or forged aluminum pistons and have many advantages over aluminum. A couple of strengths is piston cracks and erosion is a thing of the past.
A copy/paste from this link:
Unfortunately, piston selection is one area where light-duty diesel engines lack what heavy-industry diesels have had for years: steel pistons. Aftermarket, forged-aluminum pistons surfaced a few years ago but lacked the durability of OE cast-aluminum units. Fortunately for us, Mahle Motorsports came up with the Monotherm: a forged-steel, extreme-duty piston. And while they come at a price, they can be used for any purpose and in any application, from daily drivers to tow rigs to competition-only vehicles. The Monotherm piston is as much as 100 grams lighter (in certain applications) than comparable cast-aluminum units thanks to the removal of unneeded material. It’s also much stronger thanks to its high-grade, chromoly-steel construction. Designed to withstand extreme, in-cylinder heat and equipped with oil cooling galleys to reduce thermal stress makes them the best of both worlds. This piston can be part of your million-mile puzzle or your 1,000hp competition killer.
LinkShinerBock wrote:
FishOnOne wrote:
The biggest news is the steel pistons that will handle some serious cylinder pressures along with a stronger more efficient turbo.
This will be a serious medium duty engine.
Steel pistons are nice and stronger IF they are the same size as the older pistons. If not, then they are just using it to to save weight. That is just like high strength steel frames. Stronger metals can be used to reduce the mass which reduces weight, but it doesn't necessarily meet stringer over all. It just means that you can use less of the stronger metal to achieve the same strength of using more of a lesser metal.
Steel pistons have advantages over cast aluminum but saving weight is not one of them. Steel pistons are stronger, they offer longer lasting more stable ring grooves, they expand with heat similar to the compacted graphite engine block, they allow for oil galleries to be incorporated into their design for better cooling.FishOnOne wrote:
The biggest news is the steel pistons that will handle some serious cylinder pressures along with a stronger more efficient turbo.
This will be a serious medium duty engine.
Steel pistons are nice and stronger IF they are the same size as the older pistons. If not, then they are just using it to to save weight. That is just like high strength steel frames. Stronger metals can be used to reduce the mass which reduces weight, but it doesn't necessarily meet stringer over all. It just means that you can use less of the stronger metal to achieve the same strength of using more of a lesser metal.larry barnhart wrote:
Cummins12V98 wrote:
Will be interesting to see how they all do hooking to a 30k load.
Recent Dyno run with a stock 19 Cummins with advertised HP of 400 hit 392 on the rollers. I believe the Cummins filtration is 4 microns.
I think all 3 will do just fine.
chevman driving old iron.
True!FishOnOne wrote:
The biggest news is the steel pistons that will handle some serious cylinder pressures along with a stronger more efficient turbo.
This will be a serious medium duty engine.
Weren't the last about 5 versions of the 6.7L? ;)- Purchased an obscene amount of Ford stock in 2008 for less than $1.00, made enough monet to retire at 55 and have my rig custom built to my specifications.
- Purchased an obscene amount of Ford stock in 2008 for less than $1.00, made enough monet to retire at 55 and have my rig custom built to my specifications.
