[tjett]

Why is it that some RV-8's have a air intake on the lower cowl and others don't? Are there benefits to having it or not having it? Does it depend on the engine installed. I think the 8's without the air intake on the lower cowl look better. Thanks for any information on this.

 

[AltonD]

I don't know exactly about the -8, but for the -7, the fuel injected horizontal intake get the smooth cowling.

 

[Guy Prevost]

It depends on what you do with your engine. 200hp, angle valve engines are all forward induction with the smooth cowling. 180hp, parallel valve engine you have your choice, depending on whether or not you use FI, and what sump you choose. It's basically like this.

Carbureted = nostril in cowl.
Fuel Injected with vertical induction = nostril in cowl.
Fuel injected with horizontal induction=no nostril in cowl.

 

[chaskuss]

It depends on what you do with your engine. 200hp, angle valve engines are all forward induction with the smooth cowling. 180hp, parallel valve engine you have your choice, depending on whether or not you use FI, and what sump you choose. It's basically like this.

Carbureted = nostril in cowl.
Fuel Injected with vertical induction = nostril in cowl.
Fuel injected with horizontal induction=no nostril in cowl.

To expand on what Guy stated, only the IO-360-Axx and IO-360-Mxx series have forward facing [horizontal] fuel injection servos. The -Axx are "angle" valve engines. The IO-360-Bxx series have vertical servos. Both the -Bxx and -Mxx engines are parallel valve models.
The IO-360-Cxx series are also "angle" valve engines with rearward facing horizotal servos. The sumps on these engines can be converted to forward facing servos. These conversions only work on the tail dragger RVs. For more info on the conversion see

http://www.vansairforce.com/community/showthread.php?t=41657

The forward facing sumps and intake tubes can be retro fitted onto the parallel valve 360s. It's not a cheap conversion, however. A new sump and 4 intake tubes is about $2200 from AERO. A sump and intake tubes from an IO-360-Axx will cost you about $1000 [or more] in good used condition.

Charlie Kuss

 

[scsmith]

one other configuration

Some of us with horizontal induction sumps still put a ram-air intake in the cowl. It is much closer to the spinner than the intakes you see on the carbureted engine cowls.