Small Continental Engine Cooling, Center Hole

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Announcing New Carbon Fiber Nose Bowls from R&B Aircraft

Source: 2014 Q3 Beartracks
14q3sBob has started producing a carbon fiber version of his composite nose bowls for the Bearhawk 4- Place and Bearhawk Patrol! These new parts are 51% lighter, for a savings of nearly a pound.
Bob is producing them in-house and they are available as one-piece layups or split in two with an overlapping flange. With careful research and development, Bob has developed a flanging technique that gives the split bowl a nice tight fit at the seam that will require no filling. These nose bowls do not have a molded flange around the perimeter for the cowl aluminum, which is an intentional design choice. When parts like these have a molded flange it can be hard for a builder to figure out exactly where to cut the overlapping aluminum so that the cut is parallel to the flange. The accuracy of this cut will determine the aesthetics of the gap. With these nose bowls, the builder can fabricate the entire cowling with the parts as delivered, and then form a small fairing at the junction, if desired, in the final stages of paint prep.
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Bob suggests forming the fairing with the cowl in place, first by masking the aluminum and cleaning the carbon, then applying a slurry of micro balloons and epoxy at the junction of the aluminum and carbon. Careful sanding and blending of the cured epoxy will produce a nice smooth junction with a perfect fit that is custom-matched to the parts in use. These bowls are designed to blend with a 13" diameter spinner like the one from Vans aircraft. The only disadvantage of the new version is the increased cost, which is a premium of $40 over fiberglass, for a total of $225 for the one-piece or $245 for the two piece carbon nose bowl.
14q3uBob says that this price difference is a reflection of the expensive carbon fiber material that goes into the part. He is saving small pieces of the mat and plans to start producing other composite parts in carbon fiber to save weight. Look here to see more updates about progress with those projects. Bob has a limited number of nose bowls ready to ship now, and will be glad to take orders for builders who don't have an immediate need. Call him directly at 540-473-3661 when you are ready to order.

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Cooling: A Black Art

Source: 2005 Q3 Beartracks
Cooling an airplane engine is one of those controversial subjects for which there are few pat answers. What works for one, may not work for the next, seemingly identical, airplane. There are some base line parameters that have to be met and then things are changed from there.

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