RV6 - NACA Vent Locations

[Funguy]

I can kinda see where the NACA vents should be generally located on the side of the fuselage, does anyone have an exact recommended location?

Thanks in advance!

Cheers, Sean

 

[Zero4Zulu]

Mine are located in perfect alignment to the split in the top and bottom cowels. So my side cowel pins insert through the NACA vent through a small hole in the firewall and into the cowel hinges. Works nicely and no openings at the front of the cowel.

 

[bjdecker]

Copy from the -7/9

See attached --

One on each side, 2" SCEET duct from the outlet to the vent-eyeball. Will blow you out of your seat...

 

[rv6n6r]

Mine are located in perfect alignment to the split in the top and bottom cowels. So my side cowel pins insert through the NACA vent through a small hole in the firewall and into the cowel hinges. Works nicely and no openings at the front of the cowel.

Agreed. I didn't quite make it centered but got lucky that I had it close enough once I learned of this nifty cowl pin mod.
Pic shows the pop rivet with the mandrel drilled out in the vent, into which the 90-degree bent end of the pin pops in / out for removal / installation. A short section of hinge is riveted to the inside skin to guide the pin to the firewall. There are a few threads on this but that's the gist if you want to use this method.

 

[Stevea]

NACA vent location on a -6/6A

Yea, the -6 plans showed the general location of the NACA vent...no actual dimensions.

Using the best possible TLAR engineering (That Looks About Right), here's where mine are located:



Location dimensions (actually measured off the plane this morning) are:

1. Horizontal: cowl side skin (R side in photo) to forward (small) end of the NACA duct: 2 1/4 inches

2. Vertical: top forward skin edge to NACA duct center line: 2 3/4 inches


The vertical location is the more critical of the two. If the duct is mounted too low, it can interfere with the rudder pedal mounting blocks.

 

[gasman]

Set your rudder peddle blocks in place to make sure bolts and scat will clear the duct.

 

[Kyle Boatright]

Set them as high as possible. One day you may need to remove the rudder pedals, and the higher the vents are, the easier it will be to remove the weldment.

 

[PaulvS]

Yea, the -6 plans showed the general location of the NACA vent...no actual dimensions.

Using the best possible TLAR engineering (That Looks About Right), here's where mine are located:

View attachment 53472

Location dimensions (actually measured off the plane this morning) are:

1. Horizontal: cowl side skin (R side in photo) to forward (small) end of the NACA duct: 2 1/4 inches

2. Vertical: top forward skin edge to NACA duct center line: 2 3/4 inches


The vertical location is the more critical of the two. If the duct is mounted too low, it can interfere with the rudder pedal mounting blocks.

Checked the dimensions on my 6A and in comparison to Steve's measurements, the horizontal dimension is 3.0 inches and the vertical dimension is 3.5 inches. The rudder pedals are able to be removed, but only just. The scat tube from the NACA duct to the air vent (which is in the main panel) clears the sub-panel without kinking.

 

[Funguy]

Thanks a bunch

You all are awesome! Thanks for taking the time to measure exactly and the great supporting photos.

Cheers, Sean

 

[Stevea]

Paul and Kyle bring up a good point about not installing the NACA vents too low. I do remember fit checking the vents with the rudder pedal blocks taped in place…just to make sure it wasn’t too close.

Another tip: I split my rudder blocks horizontally, to make for easier installation/removal. Add in a standard thickness AN-3 washer between the block halves to make up for the lost material.

 

[gasman]

You only need to split one side.

 

[Stevea]

You only need to split one side.

True. But if you split all three (left, right, and center) it is possible to install/remove the pedal weldments one at a time. No need to wrangle both weldments together with one side bearing and the center bearing in place, and get the thing in/out at just the right angle. Been there, tried that. YMMV.

 

[vfrazier]

I've posted this before, but it never gains much traction.

On my RV-4 and on my Rocket, both having one underwing NACA vent for the rear seat ventilation and also the "standard" forward fuselage NACA vents for the front cockpit ventilation, I measured 11 degree F hotter air coming through the front vents. The difference was easily felt by hand, and readily measurable with a thermometer.

On many airplanes you'll have the option to take the cooling air from under the wing, about 3 feet out from the fuselage. You'll likely be much more comfortable in the Summer if you do.

You won't find any forward fuselage NACA vents on my new plane. 'nuf said!

YMMV.