hi guys!i was told to switch the 3 blade prop on my alpha 40 to a 2 blade one and it would give me more power?if so what size should i go with?

I have an apc11-6 on my h-9 arrow with an os 46 and its pretty fast

Well, the plane should have an Evolution .46 so an 11x6 should do just fine on it. If you want to use a spinner you will probably need to remove the flywheel. It can be carefully pressed off the prop drive hub and the hub reinstalled. Don't lose any pieces.

A two-blade prop that is 11x6 would be a good match. You could also go with a 3-blade prop with a steeper pitch to it and also enjoy more power.

Your Alpha .40 trainer with the Evo TPS engine came with a 10x4 3-blade prop. You could simply upgrade your trainer to a 10x6 or 10x7 3-blade prop and not have to buy a new spinner.

Good luck, and good shopping!

After I solo'd my Alpha 40, and broke the last of my three blade props, I switched to 11x7 APC props. I left the flywheel on, and am using the GP nylon spinner with aluminum backplate.

It is like a whole new plane with the 2 bladed prop.

just what every one said 11x6 apc (gray plastic) those 3blade arnt worth a crap

You most likely have the .45 NT engine on your Alpha. I've found the 11 X 5 that Hobbico sells for the NextStar is a great prop for trainers and should work just fine. It'll give a bit better climb and just a tad less speed than an 11 X 6 but that is fine for the Alpha - but its not like your after willing a Q-500 pylon race with it. You will find the overall performance will increase with the change to a 2-blade prop.

Hogflyer

There's nothing wrong with 3-bladed propellers in a general sense, it's just that the Evolution TPS 3-bladed prop has such a shallow pitch.

well Boys I have news for you. changing props will NOT "give you more power" . the Hp of your engine will not change one iotta. it will change how the power you have is transmited to the load & thereby the air affecting thrust out put.. a two blade will out perform the 3 blade.