Removing the "crank" from lower cowl??

[Captain Avgas]

I'm working on the lower cowl with an air intake for an RV7A (but the question would also be relevant for an RV7).

The lower cowl has a "cranked edge" ( ie. stepped) along the sides and across the front. On the attached photo I have marked the specific cranked edges as A, B, C, and D.

The drawings and instructions are specific on crank A....it gets removed. They are also specific on crank B.....it stays.

But the drawings are not specific on the cranks at faces C and D. Do they get removed or do they stay. I've checked on several RV sites and some people leave the cranks at C and D.... and some people remove them.

I asked Vans but thay are yet to reply (they may not be sure themselves !!!).

Any comments.

[zilik]

B, C and D stay. It does take some work to get them to fit right with the upper cowl.

[Norman CYYJ]

B,C, and D remain.

[jsharkey]

I removed C & D. It was pain to get everything to fit otherwise. It looks good, feels sturdy and is hidden behind the spinner.

Jim Sharkey
RV6 - Wiring etc

[Webb]

I kept them all. Had to trim the backside of "B" on right side a bit to fit. I also found that when they met had a big crack. Taped down some Saranwrap to keep from glueing top and bottom togther and filled it with flox and expoxy and fit turned out nicely.

"A" got extra glass on the outside of one side's top and the other side's bottom so they matched.

FYI - start looking at threads on pinholes and weave marks. Part of the PITA finishing of the cowl. There are also a bunch of discussions on how to finish off the hinge pins, oil filler doors, camlocks vs hinges, sanding the edges to get them straight. I think I personally researched more on the cowl than any search on this site. Thank goodness to all that have helped others here.

My own thought is Van's saved the cowl until one of the last things because if we had it first, there would be fewer of these birds flying.

Good luck.

[Captain Avgas]

I finally got the definitive answer from Vans so I will pass it on for the archives.

Vans state that it is acceptable to either remove the cranks at faces C and D.....or keep them. In other words either approach is correct.


searchwords: cowl cowling upper lower recess crank step remove spinner

[Captain Avgas]

While Vans Support confirms that it is OK to completely remove the cranks at C and D, Scott McDaniels (Vans prototype builder) says that he leaves them on. My plan now is to remove cranks C and D for precise fitting of the upper and lower cowl and then to glass in new flanges in those locations (after everything is clamped in alignment) to ensure that everything stays properly located.