New optional plans OP-58 - Lower cowl louvers for RV-6/7/9

[219PB]

Just to clarify, if one does a good job of baffling, they should not need this option? I am getting close to my first engine start, FAA inspection, paint shop date, etc. Don?t need another project. I installed a pressure plenum and everything else stock, hoping that it would be sufficient.

[greghughespdx]

Originally Posted by 219PB

Just to clarify, if one does a good job of baffling, they should not need this option? I am getting close to my first engine start, FAA inspection, paint shop date, etc. Don?t need another project. I installed a pressure plenum and everything else stock, hoping that it would be sufficient.

You'd really only want/need to install these if, after flying and optimizing baffle seals etc., you find you need them.

[Bruce]

Originally Posted by DanH

Same here.

Scott, curiosity questions please. Assuming our intrepid owner is forced to fly with crappy baffling and too much timing advance...

(1) Why not just remove the core, make the 4 ply 9-oz layup, and cut the slots, skipping the metal louver?

(2) Or, why not enlarge the standard exit? A simple 45 degree cut increases exit area by 41%. Costs nothing and can be done in 15 minutes.

Dan,
Good point.
Did #2 and made all the difference after I installed louvers. Should of opened exit first.

Boomer

[wsquare]

Does anyone have pictures, or drawing of the ?45 degree? cut that is mentioned? Unclear on how this is implemented.
Thanks,
Wayne

N1179J. Purchased flying.
2019 donation.

[WingsOnWheels]

Originally Posted by wsquare

Does anyone have pictures, or drawing of the ?45 degree? cut that is mentioned? Unclear on how this is implemented.
Thanks,
Wayne

N1179J. Purchased flying.
2019 donation.

I would also like to see some pictures to better understand how the cut would impact the interface with the center bottom support on the A models. Would a half-round cut on the sides of the exit be effective? That would prevent changing the center support. Maybe some kind of scalloped edge?

[Bruce]

I will look on this sight. There are pics somewhere.

I cut mine about 1 inch down and then toward the front of the exit.
Both sides, then open up about 2 inches and then reglass.
With the A model it opens it up as Dan said ~41%.

Boomer

[uk_figs]

I would also like to see some pictures of the cowl mod
Figs

[DanH]

Originally Posted by wsquare

Does anyone have pictures, or drawing of the ?45 degree? cut that is mentioned? Unclear on how this is implemented.

Originally Posted by WingsOnWheels

I would also like to see some pictures to better understand how the cut would impact the interface with the center bottom support on the A models. Would a half-round cut on the sides of the exit be effective? That would prevent changing the center support. Maybe some kind of scalloped edge?

Yes, you would need to modify and/or eliminate the A-model brackets. What do they support?

[Bruce]

Originally Posted by DanH

Yes, you would need to modify and/or eliminate the A-model brackets. What do they support?

Thanks for pic Dan.
Found the old thread but no pics.
Dans way is great if you don?t want to extend bracket.
On mine I made the cut at second piece of yarn, forward ~12 inches
Pulled it down 2.5 inches and reglasses.
Extended the brace.
If you take off the gear leg fairing it will slide down and rebuild brace.

I did have a Vettermans 4 pipe and it was real tight.

Look at RV-8 OR TD and you will see the exit difference.

Boomer

[DanH]

The OP-58 kit may require less fabrication on an A-model. I realize some owners are not builders.