Here you see the 3W60i mounted in our Cactus Aviation Super Chipmunk. If you don't recognize the engine don't be alarmed. I needed to machine a bit off the cylinders to fit it into the chipmunks tight cowl. If you look closely you can see yellow arrow shaft going to the needles. What I have done for ease of tuning is cut off a bit of the low and high needles and solder on the heads of a 6X32 socket head screw. Very simple. now you just run arrow shaft up to but not covering the needles. You then glue to a hard point at the other end. WALLA! You now use your ball driver to adjust the needles even with the engine running. I did the same modification to the choke arm. Now you just click for choke on, click for choke off.

If you notice I did not get to involved in bringing cool air into the engine box. The 60i/70i's bigger brothers(120iB2/140iB2) are more critical in this area. Don't get me wrong. If you do wish to get some fresh air into the carb this will make a little more horsepower. I have flown it in this configuration a while with no ill effects. If you do want to put air to the carb all you need is a 11/2" dia. tube (phonolic from an old wing tube is good). Seal the box. Run the tube up from the bottom to the box. Make sure the tube exits below the fuse to catch fresh air. You then drill a 10mm hole in the box to let air the carb does not use escape. If the box is in the fuselage you can but a small hole at the tail of your airplane. This will cause a vacuum and let the air flow easily.

Remember, don't believe all you hear at the flying field. I have had much positive feed back on the rear induction engines. They have tremendous torque and with the new three port cylinder design they can achieve this at lower RPM's. This means bigger props, less noise.