I am to the point with the cowl where I am suppose to install the rubber flap on the bottom of the front lip that goes over the baffles. I am trying to see if there are alternatives because this is the most frustrating part of reinstalling my RV-6A cowl. Has anyone tried installing the rubber flap on the top of the lip? What would be the downside of doing it this way? If the flap was removable and installed on the top of the lip it would make installing the cowl much easier.
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Cowl Question/Opinion
- Thread starter ColoradoSolar
- Start date
Yep - always considered the “per the instructions” way to be a PITA.
On the RV-8A and RV-8 builds I have a removable seal between the cowl inlet and the baffle ramps (see photos). The seals are attached via nutplates on a strip of aluminum mounted so the seals is between the bottom lip of the cowl inlet and the bottom of the seals. The aluminum strip is held in place (when removed) with JB weld. The seals go in after the lower cowl is on, and come out before removing the lower cowl. The seals extend beyond the inlet to go up the inlet sides a little.
Both RV-10s use the James Cowl and Plenum. The plenum is attached to the aluminum cowl inlet rings via sleeves.
Carl
On the RV-8A and RV-8 builds I have a removable seal between the cowl inlet and the baffle ramps (see photos). The seals are attached via nutplates on a strip of aluminum mounted so the seals is between the bottom lip of the cowl inlet and the bottom of the seals. The aluminum strip is held in place (when removed) with JB weld. The seals go in after the lower cowl is on, and come out before removing the lower cowl. The seals extend beyond the inlet to go up the inlet sides a little.
Both RV-10s use the James Cowl and Plenum. The plenum is attached to the aluminum cowl inlet rings via sleeves.
Carl
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My opinion is that built per the plans does work fine. What helps a huge amount is to have the gap between the aft cowl edge and the baffle edge be as large as you can get away with. Not sure what that dimension is (maybe 3/4”)…. That just naturally makes the on/off process a little easier.
Larry,
Do you happen to know where that thread may be? I did a search on inlet sleeves and didn't come up with anything good.
Carl,
Did you not have any issues getting the seal back in place after putting the cowl on? I have seen others that made them removable but it seems to me that getting them under the cowl lip would still be difficult.
No. Make the gap about as wide as the photo and you can slip them in putting your hand under it on the side.
Sorry, I just remember he posted it. Round inlets on a Sam James cowl I think. They slipped in through the front and secured with a screw if memory serves. Since they are the shape of the inlet, they can't go in.
Basically all you need is a foam mold for each side. I would make the mold a 1/16 or more smaller. Layup a few layers. Add a layer of fabric impregnated with PMC-780 Dry Urethane rubber to form a seal.
On the 10 I made mine removable. I bonded the seal material to the aluminum frames with nut plates and Eternabond. I have a 3 blade prop and without this it would be impossible to remove cowl easily. The seals slip in after the cowl is on without any issues. I would do it again if I were a repeat offender.
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