Prop size equivalent

[Peter Smedley]

Would I be correct in thinking that a 26x12 prop has the same load on an engine as a 28x10 ?

Only asking as I might have an issue with ground clearance.

Thanks

[barrie burton]

Peter according to an online software programme,the following applies

28x10, 549 ozs thrust @5000 rpm producing 6.47 hp with a level speed of 57 mph

26x12, 527 ozs thrust @5000 rpm producing 5.77 hp with a level speed of 57 mph

I am just guessing the revs and and wether the hp is produced or required is something an expert will tell you.

In my simple language a 26x12 prop will require less effort to turn it at the same revs,albeit producing 22ozs less thrust

Barrie Burton

[Peter Smedley]

Thanks for your help Barrie...the prop is for a 120cc flat twin for a 19kg high winger. There should be enough power on tap..

[Dave Wilshere]

A 28 x 10 on a 120cc engine is light load, DA 100's swing a 28 x 10 happily. A 26 x 12 would be very light on a 120cc engine IMO
Do what the full scale did and add blades!

[Peter Smedley]

EME engines say 27x12 - 3 blade and 2 blade 28x10 , 28x12, 29x12 . The Mr Mulligan DGA-6 had a 2 blade....So, I suppose , who would notice a 3 blade whilst it was flying?