• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Prop recommendation please

Knik_flyer

Registered User
Wasilla, AK
I have an experimental Bushmaster. I have a Continental IO-360 to install. I am looking for a prop and need some ideas. Since this is experimental, I have options. I have thought about the MT three blade prop but can't find much information on it that is useful. I'll be using this for mostly off-airport. I plan to install the 35" Bushwheels. I think my empty weight will be around 1250. Any advice is welcome.

Thanks,

Russ Elliott
 
I have an experimental Bushmaster. I have a Continental IO-360 to install. I am looking for a prop and need some ideas. Since this is experimental, I have options. I have thought about the MT three blade prop but can't find much information on it that is useful. I'll be using this for mostly off-airport. I plan to install the 35" Bushwheels. I think my empty weight will be around 1250. Any advice is welcome.

Thanks,

Russ Elliott

Russ,

Get in touch with these folks: https://flight-resource.com/?gclid=EAIaIQobChMIgeS-uoTb5gIVCtvACh25ZgG6EAAYASAAEgK_QPD_BwE

They’re the experts on MT props, and super folks to deal with.

MTV
 
Sounds like an interesting project. I had a Hawk XP and liked the IO-360KB engine. When I did my Pponk upgrade I sold my old 88" 2-blade to a buddy who clipped the tips to 80" and put it on his XP. So your engine can use a prop that fits a 180 but the issue will be whether you have the power to spin it well. Why 3-blades? At 210 HP a 2-blade should be plenty and would be lighter. I take it you want composite? Are you thinking constant speed? Don't overlook Hartzell.

Does Whirl Wind make a Continental compatible prop? If so they'd be my first choice. I wonder if the CA division can fit a ground adjustable 3-blade on your flange? That could be a good fit, too.

PA- there's an obscure old AD note about IO-360 rods not meeting spec. You may want to make sure your rods comply. I had a rod break in mine. Had to buy a new engine. A nearly identical airplane had one break a few weeks later. That plane was a total loss. Not many people know about that AD. Hopefully yours was complied with long ago.
 
Last edited:
I’ve got an experimental cub with 0-360 empty weight about the same on wheels. It’s on amphibs now and I have a Catto 86-38 on it with top end 85mph on floats at 2450 rpm. Bill Rusk is using an 84-43 Catto and he says he gets about 100mph. I’ll try and post a copy from a different forum that tells us non prop smart guys which prop to use. Someone smarter than me could explain the effects of different lengths. My static is only 2250 so maybe that’s telling me I can’t get any more aggressive on pitch. I sure would like to go faster but it’s a trade off. Constant speed would be nice
 
Last edited:
0A9546CA-C84C-4B15-8A0C-A07022F8577F.jpeg
It is hard to read but the short version is,
Speed (mph)=Pitch(inches)xRpm x 60/63360(inches per mile)
 

Attachments

  • 0A9546CA-C84C-4B15-8A0C-A07022F8577F.jpeg
    0A9546CA-C84C-4B15-8A0C-A07022F8577F.jpeg
    250.2 KB · Views: 199
Last edited:
Easier formula is pitch in inches times rpm divided by 1056 = mph.
This assumes 100% efficiency but it's a place to start anyways.
But it's moot if you decide to go with a constant speed.
 
A Continental IO-360 makes max power at 2800 rpm and sips fuel in economy cruise. I've never seen a composite prop on a 360 but it would be nice to have a long prop to maximize takeoffs and provide drag for landings. Please let us know what you choose. That IO-360 on a Cub type will be pretty unique. On a 172 the performance difference between the standard 76" CS and 80" seaplane CS is dramatic. Length matters. ;)
 
Whatever prop you wind up with, I’d be very certain that that prop has been through vibration testing on that model engine. Just because a prop will bolt on a flange does not imply it’s safe.

An example is the Hartzell HC2Y 84 inch prop when installed on a Lycoming O-360. Exhibited a destructive harmonic according to Hartzell. Cut down to 80 inches and equipped with a harmonic damper assy. Made it safe.

MTV
 
Sounds like an interesting project. I had a Hawk XP and liked the IO-360KB engine. When I did my Pponk upgrade I sold my old 88" 2-blade to a buddy who clipped the tips to 80" and put it on his XP. So your engine can use a prop that fits a 180 but the issue will be whether you have the power to spin it well. Why 3-blades? At 210 HP a 2-blade should be plenty and would be lighter. I take it you want composite? Are you thinking constant speed? Don't overlook Hartzell.

Does Whirl Wind make a Continental compatible prop? If so they'd be my first choice. I wonder if the CA division can fit a ground adjustable 3-blade on your flange? That could be a good fit, too.

PA- there's an obscure old AD note about IO-360 rods not meeting spec. You may want to make sure your rods comply. I had a rod break in mine. Had to buy a new engine. A nearly identical airplane had one break a few weeks later. That plane was a total loss. Not many people know about that AD. Hopefully yours was complied with long ago.


According to the Whirlwind website, the only Continental they make a prop for is Continental O-200.

I think I do prefer composite but am not set on it. If I went with a composite prop, I could probably handle the weight penalty. If I went metal, I think I would want a 2 blade.

I'll look into the AD.

Thanks,

Russ
 
At face value your project is very interesting. I’d enjoy hearing more about it some time. Good luck with it. C’mon, spring!
 
At face value your project is very interesting. I’d enjoy hearing more about it some time. Good luck with it. C’mon, spring!

I'm guessing from your profile that you are in Alaska. I am near Wasilla. If you are local I'd be glad to show you the project sometime.

Russ
 
I live at Wolf Lake. I’ll message you to trade contact info. I like Producers but don’t know much about Bushmasters. I enjoy airplane projects and would like to hear more about yours.

Happy New Year,

Stewart
 
Back
Top