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Q-talk 120 - Follow up on Van Vleet's Q2 Cowl Mod article in Issue 119

Dave Richardson thought he might make the modification Van Vleet described in his article published in last issue. A discussion on the Q-list about this modification is worth consideration so I reprint it here.

Dave, This technique definitely works. I have used it in the past with good results. There are 2 problems that you should be aware of though. The lip creates a large low pressure area and you don't want a fuel vent anywhere near it (measured in feet, not inches). It creates a lot of drag. - Earnest Martin

Thanks Earnest! Do you think reducing the height of the lip would reduce the effect? Richard's (Van Vleet) lip was .75" in the front and tapers down to .50" in the back. How does that compare with the size you used? Could this be sized to the larger Cessna engines he referenced and needs scaling down for our smaller engines and cleaner airframe?

My fuel vent is between the fuel tank and the aft surface of the canard and it drops about 3-4" below the bottom of the fuselage on the passenger side. Is that too close? - Dave Richardson

Dave, I had problems with the vent in the same position you describe and had to move it outside the edge of the fuselage. It is really scary when your engine will only run in a nose high position. At high speeds the engine wants to quit. - Earnest

Below is a photo of Dave's vent location.

This is a great example of how we can utilize all the QBA resources to disseminate information to the group!

You can order a printed copy of Q-talk #120 by using the Q-talk Back Issue Order Page.