Air Deflector Question

[rcarson]

The air deflectors on the upper cowl are a bit of a mystery for me since they cannot be seen once the cowl is installed. I am trying to determine where to cut the front aluminum baffles on the flywheel side before I put the fabric on. Does anyone have a quick and easy (or not) way to do this properly. I have called Van's about it and they said not to trim the fiberglass deflectors but just install them full size and sand them to fit the contour of the cowling but noone has been able to give me any info on trimming the aluminum baffles around the flywheel opening. My concern is cutting too much and having to rivit a piece on to make it fit later. Any advice would be appreciated.

Also is everyone installing the air filter bypass on the bottom of the airbox? I did but I'm not crazy about it.

 

[RV8R999]

I'll assume the -7 and -8 are similar...

this is how I did it:

I trimmed both the left and right alum baffle material (for each inlet) just enough to alow the upper cowl to sit in its proper position on the lower cowl - this is a cut-fit-cut exercise so go slow.

Once the upper cowl was in place I used a marker held against the inlet ramps (those fiberglass pieces you call deflectors) and traced the contour of the ramp onto each of the alum baffles (left and right) for both inlets.

Removing the upper cowl I then cut the alum baffle about 3/8" lower than the contour line to account for the rubber material and provide a tight but smooth bend radius. This allows the rubber baffle material to compress onto and seal along the length of the ramp (actually on the ramp not the sides or underneath) rather than onto the cowl which is better than along the sides of the ramps. If you don't you'll end up with a nice leak at the forward portion of the cowl. Think about the shape the rubber baffle forms if you try to seal the very forward poration of the cowl at the seem between the two cowl halves- extend you hand staight out with palm facing left of right - your hand is the alum baffle. Curl your fingers slightly inward and this is the shape the rubber material will form if you allow the allum baffles to seal along side and forward of the inlet ramp. The space between the curl of your fingers is a nice flow tube from upper plenum to lower.

Make sense? I'll send a picture when I get home if you like.

 

[rcarson]

Air Ramps

Thanks Ken. I would appreciate a picture to reinforce what you are saying. I did mark the aluminum just the way you described but was hisitant to cut it not knowing if anyone had been successful in doing so before. Probably looking at another six months or so to completion.

 

[Ralph Inkster]

Another neat process I heard about recently.
Buy a box of paper clips, the 1.5" ones, install them all around the baffles, then gently lower the cowl down to position, which will push the paper clips and define the cowl's inner contour.

 

[BillFear]

photo

Ken, we are redoing our baffles and would love to see that picture as well! Would also like to see how you did the seal to the lower cowling.

Thanks