Engines

In performing 3D maneuvers, there is not a lot of airflow over the engine. The plane is not moving forward as it would when you are flying it regularly, so it is important to make sure the engine remains cool. To do this you must have the proper baffling on the intakes of the cowling to direct the air at the cylinders. It is important that you get the baffling as close to the cylinders as possible, as the air will find the direction of least resistance. This is usually down in front of the cylinders. The air must be directed over the cylinders and between them and the firewall. Note: The engine shouldn't be mounted to close to the firewall, as this will restrict the air form circulating between the firewall and the cylinders.

It is also helpful, if you have a REAL overheating problem, to put a air dam on the front edge of the opening on the bottom of the cowling. This will create a low pressure area behind it, and will draw the air out of the cowling, which in turn , pulls cool air in the front.

A good rule of thumb is to have 3 times the area of exit area on the bottom of the cowl, than intake area in the front.

If my engine keeps quitting what should I do? I get asked this all the time. The first thing you should do is richen the high end needle value. What causes the engine to quit is that its getting hot. If it is running rich it will not quit. Avoid it running smooth. You want it to have a little burble. If it sounds like a sewing machine, well that's not good. That means it is going lean and it is getting ready to quit. Don't be afraid to turn the needles. I have guys all the time tell me there engine isn't running to peak performance but they are afraid to turn the needles. Always remember rich is good and safe but don't sacrifice performance because your afraid it will get hot.

What kind of OIL do you use? I use Amsoil mixed at 100 to 1. I feel this gives me the best lubrication and performance of any other oil out there and I've tried them all. When an engine is brand new I use a petroleum based oil, usually Lawnboy ashless, mixed at 50 to 1. Run about 5 gallons of gas through your engine with this and it helps break it end a little quicker.

How often should I check my sparkplugs? I check my plugs about every twenty flights. I check them for carbon build up and I set the gap.

How often should I check my prop bolts? You need to check your prop bolts about every two to three flights when your prop is brand new. After its been on for a while, check it about every ten flights. If it recently been taken off I go back and check it right after the first flight and then proceed to check it periodically.

How do I keep my mufflers from leaking and the bolts coming loose. I use Versachem High Temp Red Silicone, Type 650. You can get this at Auto Zone. I put a very thin layer on the mufflers and the flanges on the engine. Let this dry for 24 hours. I have 1000's of flights without any leakage. To keep my muffler bolts tight. I use a Q-tip with alcohol. I clean the bolts and the treads in the heads good. I then use the red Loctite high temp thread locker. This has worked very good for me. If you ever need to get your bolts out a small torch with a little heat applied on the bolts makes it very easy.