Originally Posted by 52larry52

Excellent job on the engine and cowl installation!!! That gets my "seal of approval", for what ever that's worth. Look at several J-3 Cub cowls from the head on view and you will see most have three openings just below the spinner. The top one is the widest and is a horizontal slot, below that is another horizontal slot less wide that the top one, and below that is a square or rectangular oil cooler opening that will be in that raised area near the bottom front of your cowl. Some don't have the oil cooler bump but yours does. After laying out how you want to do these, cut them open so air can enter the cowl for a little additional cooling. The unused muffler tunnel plus the area around the exhaust pipes will allow plenty of air exit from the cowl. General rule of thumb is to have twice as much exit area as intake area for air flow cooling. you have plenty. This will also give a more correct scale look to your cowl. You have a nice looking plane going there. As to the fuel tank fueling; has the tank been assembled yet? There is a 2 fuel line system and a 3 line fuel system. The 2 line would use a accessory fuel valve (Dubro or Great Planes) that would be mounted somewhere on the cowl like the side or the bottom and it consists of a spring loaded valve with hose fittings inside the cowl to the tank on one end and to the engine on the other end. A metal fueling nozzel for the end of your fuel pump hose is supplied with the valve assy. They work nice when they are new but will stick open when they have a couple of years on them and will require replacement. The 3 line system has an extra line going into the tank and will require a "fuel dot", also to be mounted on the cowl. The fuel dot is just a nice finished looking spot to mount an exit spot for the extra fuel line and will have a nice machined plug for the end of the fuel line plug. 3 line with a fuel dot will be cheaper @ $4-$6, and the fuel valve will be about $12-$13. Both available from your hobby store. Some just let the extra fuel line hang out the bottom of the engine bay and plug it with an old screw. YUCK, YUCK, looks non scale and sloppy, but that's just me again! The dangling line with the old screw plug works but come on you can do better, Go with a nice fuel dot or fueling valve.