Behind Spinner Baffles: Cut and Seal?

[RudiGreyling]

Hi Guys,

Looked at the plans for 2 hours, trolled the site and internet now for an hour, but just don't get the right answer or picture, so I am going to ask...

What is the correct way to seal the inner baffles behind the spinner, where it transitions from the sides of the inlet to the back???

Heres the problem...the top cowl inlet ramps stop abruptly where they move inboard. If you cut the inboard baffles down to match the contour of the inboard inlet ramps, the baffles don't transition nicely to the top of the cowl (i.e. from the side of the inlet ramp to the top of the cowl)

Outboard no problem, but inboard??? I just don't get it??? Frustration and I don't have a RV nearby to check out!!

Do I need to cut the inner baffles down to the contour of the inlet ramps and then straight up like my blue line? The inlet ramps don't run all the way inboard to give you a nice contour as the outboard ones do??? (In the picture below the top has already been trimmed to match the cowl..)


If I do how do you seal it on the transition???

Pictures and or advice appreciated???

Thanks in advance...Kind Regards
Rudi

[pierre smith]

Hi Rudy,
Don't cut along your blue line. If you could imagine the forward piece of baffling laid out flat, it would have a semicircle shape. Then if you bent the sides forward, that's what it would look like. I'll try and upload two RV4 pictures.
[IMG][/IMG]
[IMG][/IMG]

You just have to steadily work on this area to be sure that the rubber seals well here. A Formula 1 guy told me a long time ago that when air squirts out from behind the spinner in this area, it is like a vertical barrier and costs speed, so take your time here. Hope this helps,

[rv6rick]

Hi Rudy,
It's actually very simple ......just follow the contour of the inside of the cowl all the way around....including the ramps. It's no different for the forward section. Don't cut at your blue line or you'll have a gapping hole at your inside corner . Just make nice smooth 'rounded' cuts and again...remember to follow the contour of the inside of the cowl....whatever it takes. I like to lay the top cowl in place then, stick my hand in there with a sharpie and drag the marker along the inside of the cowl (leaving a scribe line on the baffles). Cut, then repeat till the cowl will drop all the way down where it's supposed to be. I have pics but I'm sure someone will post a few before I can dig mine out. I'll check back and post 'em if you still need them.

As a side bar....don't use those ugly pop rivets to install the baffle seals. #8 cad plated hardware is much more functional if/when you need to remove/repair the seals and are much more attractive. The hardware also will not put a dimple in your baffles like the pops will.

[jsharkey]

Rudi,
I'm at the same stage as you are and have just made the cut and fitted the seal. I'll post pics when I take them tomorrow. My cut line was somewhere between your blue line and the other pictures above. It's more of a blend than a step and I have a big overlap of the seal.
Jim Sharkey
PS - told you the baffles would be a pain in the bahooky!

[sportpilot]

We are doing the exact same thing at this time. Do not cut your blue mark. Look carefully at your drawings and study how the airseals will form a gasket from the lower cowl air inlet, to the baffle floor, and then up the sides of the forward bulkhead, and around the inside of the top cowl. Cut the forward bulkhead to contour around the inside of the top cowl with 3/8 clearence gap. The airseals will fill this gap and seal against the cowl.

[RudiGreyling]

Hi Guys, thanks so far..

Some say it follows the top cowl all the way, some say it follows the inlet ramps. I am seriuosly worried about the transition. It seems if you just keep it high along the cowl, there would be a big gaping hole alongside the inlet ramp. If you cut it down along inlet ramp contour you have a step from the ramp to top of the cowl and another big gaping hole.

I must be stupid cuase I just don't get it PICTURES PLEASE!! Preferably a RV7

[JHines]

Couple of photos from Dan's webpage.

http://www.rvproject.com/annual2005.html

Love that search function

[dan]

I have since sealed the inboard nose baffles. I use the term "sealed" loosely....

[jsharkey]

Originally Posted by dan

I have since sealed the inboard nose baffles. I use the term "sealed" loosely....

Dan,
Did you notice any difference in cooling and/or performance when you added the extra sealing?
Jim Sharkey

[dan]

Originally Posted by jsharkey

Dan,
Did you notice any difference in cooling and/or performance when you added the extra sealing?
Jim Sharkey

Zip. Nada.