Pmerems

Well Known Member
Advertiser
Gents,

For those who have a vertical induction engine I have a question about the seal from the lower cowing inlet to the FAB.

I understand there should be 3/8" or more gap from the FAB box to the cowling inlet that the builder glasses in (Foam block trick) to allow for easier removal of the lower cowing.

Should the FAB seal be butted up or overlap the inlet?

Input would greatly appreciated.

Thanks,
 
I am about ready to finish...

...the seal this next week. RV-6A FAB instructions indicate the seal material wraps around and attaches to the bottom and sides of the FAB snout...overlapping the same respective areas on the lower cowl air inlet.

The small piece of seal material also attaches to the FAB snout, only on the top. But it is then trimmed to be flush with the rear top edge of the inlet opening. This allows the lower cowl to drop down as it is removed from the aircraft. The stiffness of the seal material "keeps" it in alignment with the air intake opening / airflow in flight.
 
Follow the plans

Paul,
I glassed in the tube on the lower cowling right in line (foam block) so that it had about a 3/8-1/2" gap to the FAB inlet. Rivet on some of the baffling mat'l to the FAB so that it overlaps the fab'd tube from the lower cowling by about 3/8" and then when I'm installing the lower cowling I just have to reach in with a finger and make sure the fabric slides outside the tube extension of the lower cowling. This ensures that you have a good sealed airflow directly into the FAB. Hope that makes sense.