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Speed of Air Pistons

Haha- yeah, those cost money which is rarely spent on the 6.5.
There is no noticeable power gains nor mpg gains.
The lower egt is not a factor until pushing REALLY high numbers and the 6.5 being idi instead of di does not get as much benifit from it.

Notice he doesn’t even mention the coating which so so well proven it isn’t worth mentioning to most of his customers- but here almost no one invests in that.
 
Question I have is what differential improvement does the Dremel treatment get above the ceramic treatment?

I looked over some of the Speed of Air material and am having a tough time picking out whether the redesigned pistons offer the claimed benefits, or all the other changes that occurred to the engine when the redesigned pistons were installed are actually the main (or only?) benefit. As an example, I read over the 7.3 narrative where in addition to a swap of pistons (and gapless rings), the injectors and tune (and maybe turbo?) were modified from OE at the same time. Also, the tune can effect emissions and reduce noise at idle which has me even curious as to what is really changing. So, there are too many deltas for outright claiming that the pistons are the secret sauce.

If somebody can find where just the pistons were changed (with NO other mods) and all these observed benefits (efficiency gain, soot reduction, noise reduction, etc.) were realized, I'd start a budget. But so far, the benefit looks like it comes from a bunch of known mods to boost power and the main difference that most people do not do is ceramic coating the piston head. So, unless I can see independent test results from just the Speed of Air pistons as the only change, I'll pass. At best, I might send my pistons to Chris for his magic :cool:
 
Yeah, I have Chris’ 18:1 pistons but not these so what does that say?

I can imagine how it would help on the Cummins, Dmax, etc piston but in an idi…not holding my breath. Super high rpm engine- absolutely. But 4,000 rpm and the fact that our fire comes from a pre combustion chamber …

IMG_2967.jpeg

I sent this to a hummer owner when discussing it the other day.
I see a “wall” of air in blue and the red as the original flame front area. The blue wall could create a bigger pocket & enlarge the pocket into the yellow area.
Obviously all exaggerated for the concept.

But yes- a piston only swap is necessary on a dyno to know what really works.

In duramax having 30,000 psi injected fuel is great but in a 6.5 it would be disastrous. They simply function very differently.

The golfball phenomenon creates a thin layer of air around the ball lessening the disturbed air flow. So if this lessens mixing- then what is it doing to the airflow into the precup, and out the precup as a flame front that is supposed to spread across the piston.

I had a hydrodynamic engineer look at the pistons Chris makes for the 18.5:1 & 18:1. He expects same thing I do: the moon shaped channels (the guy had an actual name for that shape but I forget) will help the flame front spread quicker across the piston.

We would have to do a similar test between the TSP 18.5:1 to the Mahle ones without any other changes to the Engine in order to verify which design is actually better. It seems to me Mahle only engineered the different pin to deck height in order to gain their compression ratio and went with the same concept that was created for this piston back in 1982. I have no idea if Chris just winged it of hired a hydrodynamic engineer for the shape- but the guy I spoke to was impressed with it enough he asks me about every 4 months how I like it. Threatened to come build the engine himself if I don’t get it done this year- haha
 
Will L. said:
I can imagine how it would help on the Cummins, Dmax, etc piston
Click to expand...

Don't forget the HEUI pushing fuel at ~20Kpsi ;) I am getting close to the point of getting my restomod moving again on the Ferd and if this stands to notably improve combustion, I just might bite on that bait which is why I am curious about the SoA pistons. So far though, the only thing I'm convinced of is sending the original pistons to Chris for ceramic coating, and adding gapless rings.
 
my biggest problem with his they advertise the gains.
They never show only the dimpled piston swap comparison.

Dimples which change compression ratio- coated, gapless rings micro polished cross hatch cylinder wall finish with adjustments to the program to “correct it”.

Find one proof of dyno where a guy takes a simple engine like small block chevy and swaps only the piston and see the results.

Reminds me of 40hp injectors. They are because they say they are, not because they prove it. Yes I know the sema thing - thats what I am referring to above
 
I'm going to pursue this, no I won't prove or disprove it's worth, I'm interested. My rendering will have the needed valve reliefs ( needed for long duration cam grinds ) and dimples.

My current design has not been proven or disproved either, but the theory is sound, so why not dimples...

From studying it for our application I can see how dimples in the recardo area could improve the flame path by having more surface area that is not flat, but has small curves upward, the dimples on the entire piston may provide added mixture of in coming air charge and flame.

And as far as lowering compression, that's going to be hard to calculate, I think it will be small at best, the dimples are not large or deep...

dimple pic.png
 
Twisted Steel Performance said:
I'm going to pursue this, no I won't prove or disprove it's worth, I'm interested. My rendering will have the needed valve reliefs ( needed for long duration cam grinds ) and dimples.

My current design has not been proven or disproved either, but the theory is sound, so why not dimples...

From studying it for our application I can see how dimples in the recardo area could improve the flame path by having more surface area that is not flat, but has small curves upward, the dimples on the entire piston may provide added mixture of in coming air charge and flame.

And as far as lowering compression, that's going to be hard to calculate, I think it will be small at best, the dimples are not large or deep...

View attachment 92684
Click to expand...
I was just having fun here.
 
Twisted Steel Performance said:
I'm going to pursue this, no I won't prove or disprove it's worth, I'm interested. My rendering will have the needed valve reliefs ( needed for long duration cam grinds ) and dimples.

My current design has not been proven or disproved either, but the theory is sound, so why not dimples...

From studying it for our application I can see how dimples in the recardo area could improve the flame path by having more surface area that is not flat, but has small curves upward, the dimples on the entire piston may provide added mixture of in coming air charge and flame.

And as far as lowering compression, that's going to be hard to calculate, I think it will be small at best, the dimples are not large or deep...

View attachment 92684
Click to expand...
Be like having a bunch of miniature hemi heads pointed in the opposite direction.
 
The only down side I can see with the dimples is some years down the road when someone does a barn find revival and sticks a camera down in there and sees them on the piston with all the carbon might think the engine chewed on something LOL
 
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