I have a Thunder Tiger pro 46 engine on a Great Planes venus airplane. The engine always ran fine until I mounted it inverted. Everyone I have talked to has said the only fix is to mount it on a 90. I am looking for a better solution since the plane is designed for the engine to be inverted.

get an onboard glo system,that should sort it.

Does it run badly, or is it just hard to start?

I had enormous problems with my inverted engine in my Focke Wolf that I gave up and mounted it sideways. I did try a fuel line clamp and that helped but didn't fix the problem. The consensus from everyone seemed to be that the location of the fuel tank in reference to the carb was of most importance. I just mounted another engine inverted this week and made sure to get the fuel tank position correct and so far no problems.
Pat

You tank is most likely too high. You want the tank at the same height as the carb. If you mount your tank like your used to with an upright or side mounted engine, it will be too high.

I use inverted mounts with TT .46 Pros & generally I have no problems with the engines, once they are running. I have had problems with flick-starting, but never with an electric starter. Try & mount the tank as low as possible in the AC. The TOP of the tank should not be higher than the carb, if you can avoid it.

An inverted configuration that helps is "3/4" inverted, rather than fully inverted ( the engine is rotated 135 deg down from the normal upright set-up). This puts the muffler directly under the crankshaft & down the centreline of the plane. The carb is thus positioned somewhat higher in the airframe than in the fully fully inverted case. It also minimizes the bits that stick out of the cowling.

Heres one for you to think about I had a ST40 mounted inverted and it would not run properly until I took the pressure line off the muffler. Since I couldn't move the tank taking the pressure off the tank made here run realy fast and was very reliable only had a couple of engine out situations. Try it you mite have a great running engine there's just too much fuel.

hi

the most obvious problem in installing an engine inverted is the tank position. try to position the tank so the center line of the tank is about 3/8 to 1/2 inch below the center line of the ventura or the fuel nipple on throttle. if tank is higher than this the fuel will siphon into the engine flooding it, extinguishing the glow plug. most modern engines will run as well inverted as well as upright with proper set-up.

happy flying
pt19 flyer