Engine cowl louvres. Open or closed?

[Joe Mckamey]

We bought our 12 from a company that works with high school students who build these over a 2 year period. Overall an ok experience, although we are having to fix some things that weren’t done quite correct.

One question I have is about the louvres in the engine cowl. Ours are not cut out. Attached here is the directions that say to “follow these steps if you have the older cowl”. How do I know if I have the newer or older cowl and does anyone else have their louvres still closed and uncut?

 

[jsalley]

The “new” cowl has the louvers molded into the cowl, but with the openings for each louver uncut. The older type has a flat molding, with a separate part for the louver as shown in your attachment. It is essential for proper engine cooling that these louvers be open.

 

[BobN54]

We bought our 12 from a company that works with high school students who build these over a 2 year period. Overall an ok experience, although we are having to fix some things that weren’t done quite correct.

One question I have is about the louvres in the engine cowl. Ours are not cut out. Attached here is the directions that say to “follow these steps if you have the older cowl”. How do I know if I have the newer or older cowl and does anyone else have their louvres still closed and uncut?

They are suppose to be open. There are very light scribe lines for the cuts that are visible if the cowl hasn't been painted. A Dremel with a diamond cutting wheel and a set of small files are the tools we used to do ours. Pictures after cutting and filing: