Thank you all so much for the replies. Let me see if I’m unpacking the knowledge well.
“want more, change size of injectors.”
I’ve come across that as one of the typical upgrades for the 8v92t’s. My initial thought though, was that “upgrading the charger” would be a simpler bolt on upgrade. I’m aware that those types of upgrades can also require the fuel system to be upgraded but it still seems like upgrading the blower/charger wasn’t/isn’t done. Is it a “can’t do it” issue?
“Technically they are not superchargers. They provided minimal boost if any, they are called scavenger blowers”
Is this why a twin screw charger isn’t or could not replace the roots blower? Since they are both positive displacement, I’m not sure what would be the drawback. Too much Pressure?
“I would guess that everyone sticks with the roots type because the blower doesn’t make major boost in these applications, the turbo handles that.”
If I’m understanding the nature of these engines, the factory blower doesn’t need to make “major boost” to scavenge. While seeking excess power numbers, I’m wondering why this particular bolt-on part seems to have been left alone. I guess I thought it would be often mentioned why competitors at these levers don’t or can’t change to a more efficient charger that “does” add more power while also providing the positive displacement for scavenging. *Twin screw – Twin Turbos*,,, why not?
“Scavenger blowers, roots type which are referred to as positive displacement, are necessary for them to run. The exhaust valves open when the ports are open. The pressure from the blower pushes the exhaust out through the valves and provides fresh air”.
I’ve seen the internals of the 2stroke diesel, and I comprehend how the blowers are needed to force the exhaust gasses out. I’ve wondered if replacing the roots blower with a twin-screw supercharger would supply “too much” air in the lower rpms for this type of engine? I’ll be honest and say I can’t see that being a problem but again, I’m not seeing/reading a clear reason why this could be counterproductive.
I found some interesting builds of a twin charged Cummins. The first video has a roots blower and the second has an Eaton screw-type. I’m not comparing the Cummins to the 8v92t, just wondering if the same thing could be done to the 8v92t by replacing the roots with a screw-type charger.
Roots/turbo –
Eaton/turbo –
