Adding NACA vents to already-built canopy skirt

Hi all,

How difficult would it be to add NACA vents to the canopy skirt of a fully built -4?

I see them on some a/c and as I like a lot of cooling they look like good ideas. But I'm in the midst of looking for a used -4, and some have them...some don't.

IS it hugely difficult to add them after the fact?

thanks

Dont

They mostly dont work good on canopy skirt. Its a bad location for naca vents. Lots of threads on this. Here is a current one:

http://www.vansairforce.com/community/showthread.php?t=114615&highlight=naca

Dont do it!

If you havent already got them just below the cowl cheeks, put them there. I have one on each side, and a 3rd on the R/H wing lower skin with ducting to rear seat. All produce good airflow. The skirt location is not in a high pressure area and will not do as well.

What Bill E said.

I've got one on the starboard side just below cowl cheek ducted to an eyeball vent centered in a center console just below the panel. That cools me fine.

Second in the right wing ala RV-8. Ducted to vent for rear passenger.

Works great.

NACA Vents in Canopy Skirt

I did what you are considering - all I got for my troubles were exit vents! If I ever got smoke in the canopy they are a great thing to have; otherwise, not so much.

If you still consider installing them, I would suggest some "tufting" experiments to see if you can find some higher pressure locations on the skirt than I found.

YMMV

Thx

David

RV-4 VENTS

All

I have one of these (CA LV-3 vents ) on the right rear skirt of my RV-4 and it does really work and looks good.I also have 2 Naca ducts about 6 '' under each cheeks and there is so much air going thru them that they set the squelch off my radio...

I also have a small flap on the left fwd side skirt which I rarely use these days even with temps in the 90s like last week..

So there are ways to cool an RV-4

I'll try to take pictures tomorrow.

Bruno

Not so much...

Saville said:

Hi all,

How difficult would it be to add NACA vents to the canopy skirt of a fully built -4?

I see them on some a/c and as I like a lot of cooling they look like good ideas. But I'm in the midst of looking for a used -4, and some have them...some don't.

IS it hugely difficult to add them after the fact?

thanks

Click to expand...

Gregg,
The original RV4 plans called for the canopy skirt vents but most of us Jurassic builders (especially us Southern Boys) discovered rather quickly in summer months that they didn't work well. Even after tufting them and installing VG's they are minimal cooling at best to this day. There was a very recent post on this very subject BTW, Tom posted a link above or...search NACA vents.
As previously mentioned, the fuselage is a much better place to install them, 6" below the permanent aft cowl bump at a 2 degree down angle to the 0 degree waterline. (canopy rail is close to zero)

Another great idea is to install Larry Vetterman's flip out vents sold by Van's now. http://www.vansaircraft.com/cgi-bin...rowse=heatvent&product=ventilation-components
Purchase two, install them 6"below the canopy rail 8" aft of the fwd fuselage bulkhead and one aft of the roll bar at the same height for your pitters. Spendy but worth it.

Want less holes showing on the pretty airframe? Cut the NACA vent into the bottom of the aft cowl bump and plumb the SCAT into the cockpit cutting a hole through the fuselage into the cowl cheek. Alot of work but works great when completed. For the aft cockpit, purchase the Vent Kit from Van's and install another NACA hole on the underside of the right wing aft of the spar and plumb it into the rear cockpit ala RV-8. Works very well on the 4. Lots of airflow from both and nearly invisible when parked. Lastly, the RV-10 flip out vents work very well and close flush, good for keeping cold air out during your chilly Yankee winters...

V/R
Smokey

PS: Installing any of these requires some basic sheet metal skills, if you're a buyer not a builder or don't have tools or the "skills to pay the bills", stop by your local EAA chapter and ask for some help. You will find lots of new friends if you haven't already

By far the easiest and most effective way to cool an RV-4 is to add four (One on each side front and one on each side in the rear.) of the vents Van's supplies in RV-10 and RV-12 kits. Install them below the canopy rails. I instaledl the two on the left about a foot lower than the ones on the right. And it is very inexpensive.

Part number

skiandtom said:

By far the easiest and most effective way to cool an RV-4 is to add four (One on each side front and one on each side in the rear.) of the vents Van's supplies in RV-10 and RV-12 kits. Install them below the canopy rails. I instaledl the two on the left about a foot lower than the ones on the right. And it is very inexpensive.

Click to expand...

Got a part number for these ?

Thanks, Gregg

smokyray said:

Gregg,
The original RV4 plans called for the canopy skirt vents but most of us Jurassic builders (especially us Southern Boys) discovered rather quickly in summer months that they didn't work well. Even after tufting them and installing VG's they are minimal cooling at best to this day. There was a very recent post on this very subject BTW, Tom posted a link above or...search NACA vents.
As previously mentioned, the fuselage is a much better place to install them, 6" below the permanent aft cowl bump at a 2 degree down angle to the 0 degree waterline. (canopy rail is close to zero)

Another great idea is to install Larry Vetterman's flip out vents sold by Van's now. http://www.vansaircraft.com/cgi-bin...rowse=heatvent&product=ventilation-components
Purchase two, install them 6"below the canopy rail 8" aft of the fwd fuselage bulkhead and one aft of the roll bar at the same height for your pitters. Spendy but worth it.

Want less holes showing on the pretty airframe? Cut the NACA vent into the bottom of the aft cowl bump and plumb the SCAT into the cockpit cutting a hole through the fuselage into the cowl cheek. Alot of work but works great when completed. For the aft cockpit, purchase the Vent Kit from Van's and install another NACA hole on the underside of the right wing aft of the spar and plumb it into the rear cockpit ala RV-8. Works very well on the 4. Lots of airflow from both and nearly invisible when parked. Lastly, the RV-10 flip out vents work very well and close flush, good for keeping cold air out during your chilly Yankee winters...

V/R
Smokey

PS: Installing any of these requires some basic sheet metal skills, if you're a buyer not a builder or don't have tools or the "skills to pay the bills", stop by your local EAA chapter and ask for some help. You will find lots of new friends if you haven't already

Click to expand...

Hi Smokey,

I read the recent post before I started this thread. The impression i got was that the problem with air flow may or may not be due to the location and design of the vents themselves. And they seemed to work for some writers int he thread but not others.

But I like your ideas better....they really need to work in my case...

.....some of us Yankees need a lot of cooling down. During Winter flying I wear a jean jacket when pax are bundled up so much all you can see is their eyes (Though I have heavier gear on board for emergencies.)
Thanks!

The best way to cool a -4 is to install the little vents from the RV-10 and RV-12. I installed four of them in my -4. Two in the front and two in the rear. The ones on the right side, I installed about two inches below the canopy hinge. The ones on the left are about eight or ten inches lower. The left front one is just below the cowl cheek. The are very efficient, not difficult to install and are inexpensive.