| Hartstoc |
09-26-2019 09:33 AM |
Quote:
Originally Posted by DanH
(Post 1108945)
Considering all RV fabrication tasks, the thing I most often see done badly is baffle sealing rubber. Flap seals arranged so they blow open, seals that seal against nothing, puckers, gaps, overlaps, you name it...the list of sins appears to be endless.
However, I have seen some installations that were beautiful. Believe me, I look; I'm the nut case who walks around fly-ins while peering into cowl openings like some kind of airplane up-skirt pervert ;)
Builders need to see some really good seals. Who has pictures? Who can show us how it's done? Post those photos please. You'll help a whole generation of RV builders enjoy lower CHT and oil temperature, while going faster due to reduced cooling drag.
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Great thread. I?ve got nothing to offer except an out-of-the-box thought. I have no photos but will try to find.
We did a lot of work on cowl design and cooling sealing on the CAFE Foundation test Mooney back in the 1990?s. That bird actually ended up with a huge spinner from a turboprop and a 360? annular cooling inlet. I'm not suggesting that path for RV?s but the baffle seals were something completely different.
We used thin, 10 mil, flexible, reinforced silicone fabric to create a baffle seal at the engine?s horizontal mid-plane. The seal extended around the circumference of the engine cylinder mid-point line with the outer edge of the fabric attached to the lower cowl inner wall and to the firewall itself below the oil filter. A bit of a hassle accessing the lower plugs, but when you removed the upper cowl you had full access to the
Entire accessory section and the top half of the engine, with no aluminum flanges need to support heavy baffling engaging the upper cowl. The beauty of this installation is that it provided for a much larger volume decelleration plenum, and the entire upper accessory section was was in the ice cold pressure section. It was essentially a hermetically sealed partition. If I were building new I?d seriously consider such an approach. Pressure recovery of that system was in a class by itself. I?ll try to dig up some photos.-Otis
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