Volumetric Efficiency?

[stomper65]

I ordered MAMs thumper kit. I have been looking for some turbo info, just to know more, and came I came across volumetric efficiency.

I am trying to figure out what our engine's volumetric efficiency is.

does anyone know the volumetric efficiency of our engines in the progeges?

 

[flat_black]

Ahhh, a very good question! This is modified by a lot of variables; Pumping resistance, intake/exhaust restriction/sizing, and so on and so forth. As a base rule, any given engine will safely be in the 80-90% range these days. 85% is a safe percentage to assume, as a base, but portwork and so on will change these factors, as well. Reducing factory tolerances a little bit helps tighten things down nicely.

 

[stomper65]

Does anyone have an exact number for our motors?

 

[flat_black]

There is no 'exact number'. You'd have to measure YOUR own engine to get an exact number. Two of the same exact engines can vary as much as 10 percent.

Use .85, it's what most people use as a general rule.

 

[Kooldino]

Does anyone have an exact number for our motors?

The numbers vary by RPM, for starters.

 

[peepsalot]

Yeah, volumetric efficiency cannot be represented in a single number, closest you could do would be more like a table of VE across all RPM and Load values. Even with that it would vary around those number some depending on temp and a billion other variables.

 

[65racecoupe]

It would be read easier on a graph. Porting the head and having an intake manifold that works WITH the engine would help VE out.

Having said that, it is incredibly complicated.

 

[Spooled]

Hehe, I started a thread on this a while back:
http://www.msprotege.com/forum/showthread.php?t=109817&highlight=volumetric+efficiency