F22 engine efficiency

[dominate9]

What is the volumetric efficiency for an F22B1?

[rx racer]

figure 145 HP / 2.2L = 20.45 HP/L

[dominate9]

Originally posted by rx racer
figure 145 HP / 2.2L = 20.45 HP/L

I believe engine volumetric efficiency (VE) is usually in percents. VE changes with engine RPM, a engine at wide open throttle at 3000rpm could have a VE of 90% and at 6000 rpm 60%. This is a rough guide. At maximum RPM modified engines may have a better VE, e.g.: average overhead valve engines 45% to 75%, overhead cam twin valve 65% to 80%, four valves per cylinder 75% to 90%.

[rx racer]

sorry thought you were reffering to the HP/L sometimes reffered to a volumetric efficiency (dunno if thats wrong or not)

[ivymike1031]

At peak torque, VE% is often close to (or greater than) 100%.

To get a rough estimate of VE% at peak power, calculate the torque at peak power and divide by peak torque.

If you'd like me to do this as an example, please provide the following:

Peak torque output of engine
Peak power output of engine
RPM at which peak power occurs

[dominate9]

Originally posted by ivymike1031
At peak torque, VE% is often close to (or greater than) 100%.

To get a rough estimate of VE% at peak power, calculate the torque at peak power and divide by peak torque.

If you'd like me to do this as an example, please provide the following:

Peak torque output of engine
Peak power output of engine
RPM at which peak power occurs

145HP/147ft-lb @5500RPM

[dominate9]

Originally posted by dominate9


145HP/147ft-lb @5500RPM

145HP@5500RPM
147ft-ib@4500RPM

[ivymike1031]

Okay... We'll assume that at peak torque, %VE is exactly 100% (in reality it may be slightly higher and it may be slightly lower).

145HP @ 5500RPM gives us about 138 ft*lbf (145 * 5252 / 5500 =~138)

Now we'll assume that the torque drop at higher rpm is due to poor breathing (lower VE):

138 ft*lbf / 147 ft*lbf =~ 0.94 = 94% VE

So that engine configuration has a V.E. of about 94% at WOT at 5500rpm.

[dominate9]

Originally posted by ivymike1031
Okay... We'll assume that at peak torque, %VE is exactly 100% (in reality it may be slightly higher and it may be slightly lower).

145HP @ 5500RPM gives us about 138 ft*lbf (145 * 5252 / 5500 =~138)

Now we'll assume that the torque drop at higher rpm is due to poor breathing (lower VE):

138 ft*lbf / 147 ft*lbf =~ 0.94 = 94% VE

So that engine configuration has a V.E. of about 94% at WOT at 5500rpm.

Thanks for the example. So if I had the dyno chart for my Accord, I could calculate the VE at each RPM interval, correct?

[ivymike1031]

you could probably come up with some pretty good estimates.