Installing Cowl

Here are my latest images. If any one has any good tips about installing the cowl please feel free to post it here. I had to have some instant gratification.



This is my son Ian

I just finished my cowl a month or two ago. My tips would be:

1. Don?t cut anything before you know exactly how everything fits. (Upper cowl, lower cowl, cowl cheeks, clearance to spinner, centerline, how it lines up with lower fuselage, how the upper and lower cowls fit to each other.

2. If you don?t have a laser level ? get one. I bought one at Sears ($29 or $39) that sits on a camera tripod that was great for shooting straight lines on curved surfaces.

3. Read the instructions ? but only as a reference. If I would have followed the instructions to the word ? I would have been very disappointed.

My cowl had a twist in it that made it extra hard. I spent several days lining things up, taping the cowl in place, using a laser level to check the edges, etc. before cutting anything. It saved me from cutting the twisted edge way too short. In the end, it came out nice, but it took forever. I had to heat the areas by the spinner and reform them. I had to do a buildup on the front edge to make it match. In short, it took far more work that I expected.

Hope this helps,
Cameron Smith RV4 #68

Cowl fit?

I have cut the top of my cowl to the edge of the top skin. The portion of the cowl that over hangs the cheeks I didn?t cut for lack of a good reference line. I now have two concerns. The area of the cowl behind the spinner isn?t parallel to the edge of the back plate. Is it common to have to fill this area? The second concern is the cowl cheeks have a 7 ?? reference dimension. My are located at 6 ?? below the cockpit rail. Is this good?

RV4 cowl

Dayton,
My cowl cheeks ended up close to 6 1/2" also. The left side was slightly higher than the right side. At LOE 05, I looked at several RV4s. It seems like this is the norm. My spinner clearance ended up about 1/8" larger at the bottom than the top. The engine will sag a little and reduce the difference. Even at the 1/8", I didn't find it objectionable.

Cameron Smith

Cowl Update

Hi Guys

Last night I finished drilling the upper cowl to firewall hinges. I fit and drilled the cowl cheeks to the fuselage. Tonight I will fit the lower cowl. Have a great weekend!

fitting lower cowl

Hi Guys

last nite I marked the lower cowl and trimed the flange. I drilled the holes for the gear legs and cut the slot to the aft edge of the cowl. the next thing os to drill and cleco it to the hinges. here are the latest images.

Drilling Hinges

Hi Guys

Today I drilled the hinges and installed the plate behind the spinner. I installed the hinge half in the lower cowl first after locating it with the cowl installed and taped in location. Then I installed the upper hinge half and taped the upper cowl to the lower cowl. After aligning the forward edges of the cowl halves I drilled from the inside and clecoed the hinge to the cowl

Cowl Fitting

Just an Update
I trimmed and trimmed and it?s still to short! That?s how I feel!
It looks like I trimmed to much off the joint line between the cowl halves.
The radius at the lower cheek and the lower cowl are out of alignment
Is there a repair for this misalignment? The area behind the spinner is @#$%
I am not happy!

Slow Down

I was at the same place you are but with my -9. I just wanted to get the cowling on and press on with other items....not so . The cowing on the 9 did not fit at all. The foam reinforcement had to be trimmed away to allow clearance at the aft end of the top cowl.
I also had to "add" some material back in at a small area. Just lay one or two pieces of glass up over hanging the edge that is too short. After it sets up the mix up a batch of flox and spread it on top of the glass you layed up and then trim as required after it has set up. You can do about anything with fiberglass...it just takes time. Now about the alignment with the spinner...
A few pics says it all....
All you can do is slow down and work with what you have and have fun while you?re doing it.

Cowl Installed

Hi Guys
today I finished trimming and drilling the hinges for the cowl.next is the oil door and the inside ramps after I rivet the hinges. I will build up the area behine the spinner with foam and glass( thanks for the Images Mr Ping.)

Cowl alignment

Dayton, Ping et al,

In the early RV-4 builders manual that I had (#1435), Van talked about heating and clamping the area behind the spinner to get the acowl to align with the spinner. This was with the old polyester (?) cowl. I had to do this and it worked out OK. I admit there is still some load on the short cowl pins I used there, but not much. Borrow your wifes hair dryer (if you don't have your own...), and try it before you re-build that area.

VH-PIO

Spinner gap

Hi Grant

I was informed by Van?s that the new epoxy type cowls lack the thermo property of the old polyester cowls. I am going to build the spinner area up with foam and over lay it with epoxy resin and 9 oz. glass. With some luck and the blessings of the fiberglass gods
I will be able to produce an acceptable gap between the spinner and cowl.

Update

Hi Guys
I made a small panel on the top of my cowl to provide better access to the cowl pins. I will do the same on the cowl cheeks. The last couple of week it has been in the twenties in my hanger. I need a better heater, Any suggestions for a heater!

Better heater

Move to my shed, its 43 in there today. Oh, by the way, that's celcius.

Hinges Finished

Hi Guys
The last two weeks I finished the hinge instillation on my cowl. I am a little concern about the edges between the cowl halves. After riveting the hinges and gluing them to the cowl the edges are not as clean as they were. I suppose that filler and sanding will smooth the edges.
This is the plate I installed to cover up the pin ends

Left side

Right side

Next I will finish the details on the cowl then move on to fitting the gear leg fairings