2020 6.7 Power Stroke w/Steel Pistons

All I could afford wrote:
Comming soon...a TV commercial featuring A load of bricks being dropped onto a steel piston, versus A load of bricks being dropped onto an aluminum piston.

Just don't drop used and/or broken steel pistons in an aluminum bed truck, if there land with the edge of the skirt pointed down they will make a hole in the bed floor.

wrgrs50s wrote:
Wow, I was questioning the post on the steel pistons so I looked it up and sure enough, it's something that performance diesels have been using in their racing engines for a while. I never would have thought a steel piston would work because of the inertia weight. Apparently they've beefed the rods up to compensate.

Steel weighs twice as much as aluminum for the same volume. The designers may have been able to reduce the volume due to steel having a higher strength at high temperatures than aluminum but even if they didn't you can reduce the inertia stress by half just by reducing RPM by 30%. Since most diesel engines only turn about half the RPM of gas engines it doesn't sound like piston inertia would be too big of a deal. Also, any connecting rod that can survive the compression stroke of one of these diesels shouldn't have any trouble with holding the piston back at the top of the stroke.

"Also, any connecting rod that can survive the compression stroke of one of these diesels shouldn't have any trouble with holding the piston back at the top of the stroke."

Maybe, maybe not. Don't forget that the rod just has to resist the compression on that compression stroke, but when the piston gets to the end of it's stroke, then the energy is trying to pull the rod apart and the rod is fairly thin where it connects to the piston, and bolted together at the other end. The two weak links.

The steel piston is likely needed to safely increase EGT, and necessary to increase power.

Groover wrote:

wrgrs50s wrote:
Wow, I was questioning the post on the steel pistons so I looked it up and sure enough, it's something that performance diesels have been using in their racing engines for a while. I never would have thought a steel piston would work because of the inertia weight. Apparently they've beefed the rods up to compensate.

Steel weighs twice as much as aluminum for the same volume. The designers may have been able to reduce the volume due to steel having a higher strength at high temperatures than aluminum but even if they didn't you can reduce the inertia stress by half just by reducing RPM by 30%. Since most diesel engines only turn about half the RPM of gas engines it doesn't sound like piston inertia would be too big of a deal. Also, any connecting rod that can survive the compression stroke of one of these diesels shouldn't have any trouble with holding the piston back at the top of the stroke.

If you read the link to Mahle's web site I provided these steel pistons appear to be very similar in weight to cast aluminum pistons and in some cases actually lighter.

Also on this site it illustrates a funny car with a cummins spinning 5,800 rpm and 2,200F exhaust gas temps for 100 passes.

So the truck with the steel pistons will have an aluminum body, and the truck with The aluminum pistons will have a steel body?

^^^Yeah something like that... Or perhaps the next Ike Gauntlet run the truck with the steel pistons steels the show? :B

The link also said that the steel pistons could have tighter clearances and since the cylinder wall and piston expanded at about the same rate there would be less cylinder wear.

It sounds like Ford is going the extra mile to make these engines more durable but only time will tell for sure.

danrclem wrote:
The link also said that the steel pistons could have tighter clearances and since the cylinder wall and piston expanded at about the same rate there would be less cylinder wear.

It sounds like Ford is going the extra mile to make these engines more durable but only time will tell for sure.

100K dependability towing at the upper ratings is more of a concern.