I have an evo 46 engine that I'll be putting in my sig LT40. I still have the 3-blade trainer prop(new) but will this be enough for this plane. The engine manual says I can use this size and that size but no specifics. I only have about 20 flights (with the mustang pts) with 5 of them solo. My instructor recommended this plane and I want to at least dazzle him with my desision. Plus I REALLY want to fly this year as opposed to repairing my mustang. (The new mustang does look good hanging off my ceiling.)

The three blade trainer prop will work fine. You can also use a two blade 11x6 prop and it will work even better. I have this same engine on my Alpha 40 and used the three blade props until I soloed. Then I switched to 11x6 and 11x7's and performance greatly improved. The three blade props really slow the plane down by design. It just gets expensive replacing them. Just get a 2 1/2", two blade spinner. I like the ones with the aluminum backplates.

Good luck.

Thanks mc.

PS - Some people recommend removing the weighted flywheel when you switch to the two bladed props. I left it on, and everything fit fine.

I'm not familiar with the Evo .46 but have years of experience with a Thunder Tiger .46 Pro powered LT-40.

First of all, in the sizes we run for our model engines, a 3 blade prop is just not as efficient as a 2 blade prop. This is specially evident in the small ½A engines (remember those Cox plastic RTFs)?

Second of all, the LT-40 is a relatively high drag 900 sq in airplane with a low wing loading. It simply won't fly as fast as an airplane with less drag and/or a higher wing loading.

I've flown my LT-40 with an 11-5 2 blade APC or Master Airscrew prop which gives me a ton of thrust but not top end speed. I can put the LT-40 virtually at a stall attitude then open the throttle and it will power out of any "iffy" situation. APC props are more efficient than the Master Airscrew but are more brittle. If you use the stock LG like I did for a few years a minor prop strike on the runway will likely damage the APC prop but the MA prop would survive.

my05monte

Switch to a Master Airscrew or Hobbico NextStar 11 X 5 prop 2-blade and spinner. When you change your spinner you will most likely have to drive the flywheel weight off the hub to get the spinner backplate seat on the hub properly. Easy to do - place the flywheel (black part) on a vise with the jaws open enough for the hub (silver part) do drop through the jaws. Take a socket just smaller than the hub and, using a hammer, tap it off the flywheel. This will allow for a standard spinner to seat properly on the hub.

Another thing to do is take the pins out of the limiters. They do nothing but hinder the proper set-up and tuning of the engine - small needle nose pliers work fine, but you may have to twist the pins as you pull them out. If in doubt here, your instructor should be able to help you out there.

Hogflyer