RV-4 air vents

Greetings all:


I really need to increase the fresh air ventilation in my -4. Right now I am taking fresh air off the back baffle and running it through Van's mixing box into the cabin. Plenty of fresh air when in the "cold" mode, but since the air flows through the top of the cowling first, it is about 10 degrees above ambient. Not good on a hot day.

I want to install a NACA vent under the right cheek venting up to a fresh air eyeball mounted under the right lower portion of the panel. I have a fair amount of experience in knowing that there are a lot of weird pressure areas around the RV-4 cowl and canopy. Have any of you mounted a NACA vent in this area on the RHS?? Does it work OK???

BTW, I have one of Larry Vetterman's little rotating scoop things for the rear seat pax and it works very well on the RHS of the canopy skirt. But mounting a similar vent for the front pilot is useless (I had one located here on a previous RV-4 and it sucked air out!!)

Thanks

Doug Weiler
N722DW, 200hrs

I have two NACA scoops located on either side of my forward fuselage just below the cheek cowls. These go to two eyeball vents on either side of my panel. Approximately in the middle of the sheet of aluminum that makes up that side wall. They both provide a lot of fresh air. I usually keep one pointed toward the back seater and have actually been asked to close it. So, pretty good airflow.

I remember reading that some have added NACA scoops to the bottom of their wings a la RV-8 and had very good airflow. Personally I like them on the sides; easier to check for wasps and very good airflow.

Thanks Scott,

I have never heard anyone NOT getting lots of air from these locations. Here in MN/WI we worry more about getting enough heat in the winter, but we really do have a couple months of hot weather.

Doug

-4 vents

I also have the Vetterman's vents, and the one in the rear skirt is GREAT! The one I installed in the front skirt had the same result as yours. Diddley squat. Looks great, though. I think I gained 5 knots.
The area under the left cheek is preferred. Higher pressure there. I have a NACA under each wing, one for the front, one for the back. A bit tough to add after the fact, though. Larry Vetterman uses a "Vetterman" vent under the left cheek, and operates it with a speedometer cable/knob setup, others have copied it (Russ Kamtz of "retractable steps" fame) and report excellent results.

Jeff

RV-4 Vents

I mounted two of those little pre-molded NACA style vents in the LH fuse skin below the canopy skirt, one in front and one in back. They vent directly into the cockpit. Both get good flow, and in Australia in summer you need it! I could do with more on hot days, but my main bitch is my hot feet! With the 4-1 collecter exhaust exiting under my right foot, it gets a bit toasty. Have ceramic coated the exhaust, and that helped. Had a heat shield on it before, but the ceramic coating does a better job. May have to re-fit the shield. I didn't fit any heating system at all.

'build light - fly fast'

Fresh air

I live in Oregon and in the summer months it gets hot. Today it is suppose to be 98 and we will probably have a few days in the 100s Not as hot as many places but so hot my 4 would cook me in the summer.

What I did was mount a 2 inch air inlet in the front of the cowl just to the right of the spinner. I attached it to the baffeling. I then ran scat tubing back to the vertical baffeling where I attacted a flanged 2 inch tube to penatrate the baffeling. On the rear side of the baffeling I installed a 2 inch T. I ran scat tubing from each side of the tee to another flanged 2 inch tube that was installed into the rear cowl cheeks. I now had ram air into the cowl cheeks. Inside the cock pit I drilled two 1/4 inche holes on each side one by my knees and another just in front of where I sit. I then took a hole saw and cut four holes about 2 inches in diamater out of a piece of scrap aluminum material. I bent each of these at a 45 degree angle about a half inch from the center. I then scribed an arch around the holes in the fuselage. Next I drew kidney shaped holes in each of the four locations where I wanted the air to blow out at my chest and feet. Make sure the holes you make stay the half inch away from your center hole and the outside edge of the circle you scribed. Also there is no need for the hole to be larger than the area that the bent part of the cut out hole covers. I used a die grinder to do this after a half inch starter hole. Last step is to install the bent hole material you cut out with a 1/4 inch bolt and tighten it down to where you can turn your half bent hole to open the air inlet but still will remain where you put it. You will find that you can install the nut on the inside of the cowl cheek through the blow hole.
To make it short and sweet this works great. A two inch hole right out front at airspeed makes it so that I get a lot of fresh air on my feet as well as my chest and you can direct the air where you want it by rotating it where you want it. It also is a cheap way of doing it.
For the girl friend in the rear seat she has the little spendy twisty things to keep her cool one on each side.
If anyone has any questions feel free to contact me would be happy to help out. akbound@yahoo will work.
Jerry

I have just ordered a -4 so willl be interested to see any replies. Also, is there anywhere where I will find these vetterman scoops you mention Doug? Vetterman seems to sell several things other than exhausts but I have never seen a web site. Can anyone give me a link?

Thanks, steve.

PS Does the -4 fuse jit come with any form of ventilation?

RV4 vents

I think Van has the Vetterman vents in his catalog. Call Larry Vetterman and you can get some from him directly. BUT.. if I had it to do over again, I would install 2 NACA scoops on either side of the fuselage below the cheeks and behind the firewall and run aeroduct tubing to 2 small whisperflow vents on either side of the instument panel. I's have a NACA vent on the bottom of the wing ducting air to the rear seat like the -8.

No the RV-4 does not have any ventilation kit included to my knowledge

Doug Weiler

Thanks! I might just look at the RV10 vents mentioned in the last RVator.