Norvel Uniflow Setup

I have been very sucessful in using Norvel BigMig .049 engine for stunt. I found that this setup will give you an optimal run for the 6 minutes need to complete a AMA pattern. Do not use stock muffler presure setup that comes with the engine. The secret is uniflow vent.

Even a startup engine can be modified to accept the uniflow vent. This will the extend the lap count to 50+ with this tiny stock tank using 10% nitro. APC 4.7 X 4 prop and 38' lines.

Brodak BH521 1oz tank modified with a 1/8" uniflow vent. Vent uniflow tube forward to airstream. I'm finding that short length tanks work the best.
Start with at least 3 head gaskets
Use a SM (small medium) fuel line - Sonictronics #225R
APC 5.5 X 2.5 or 6 X 2 propeller
Launch at about 18.5K RPM (the lower the nitro the higher the launch RPM)
15 - 20% nitro is all you will need
Synthetic blend with at least 18% oil seems to work the best. Too much oil degrades performance.

Tank Height:

Tank height is about the center line of the needle valve with the muffler. However, if you do not run it with the muffler, I found that the tank height may need to be raised another 1/8".

Note: Use a 1/8" slice from a medium silicon fuel tubing as a bushing for APC's props.

Norvel MigBig Stunt Setup

Tank Height: