Fuel Efficiency differences 870 vs 871

[Chamberpains]

(06-15-2018 )Rawze Wrote:  I think your over-thinking it a bit there.

Last I checked, there was hot inert gases and and an EGR valve restricting flow though the venturi portion getting in the way of that effect, therefore there is no real efficiency gain. Block the EGR pipe (just commenting on what most 870 owners do) and all you end up with is a bit of unnecessary turbulence.

Oh I'm sure I'm over thinking things. It's what keeps me entertained on the long hauls. Your site is great for this.

Without the EGR nozzle in the way (completely removed) wouldn't this pipe act as a de Laval nozzle? Or probably not because all the valves and intake ports would just kill any effect it would've had. They are used more in turbine engines with a straight shot right into the combustion chamber.

After researching Detroit's early EGR systems, they used a Venturi pipe of some sort. I'm guessing this was probably used more for thoroughly mixing the exhaust gasses with the clean air. The extra turbulence was probably thought to be needed.

Some times I just need to stroll down the rabbit hole just to see what all is there.