Paul and group,

I agree about hp flys the plane. Takeoff roll and climb can be
significantly affected- so long as the proper gear ratio and prop is
selected!  An interesting tidbit on the GreatPlains web site
www.greatplainsas.com/ <http://www.greatplainsas.com/>

Using the same basic engine hp (103 takeoff, 70 continuous)

62" prop, direct drive = about 215 lbs thrust

72" prop, 1.6 drive = about 350 lbs thrust

84" prop, 2.0 drive = about 450 lbs thrust

For fixed pitch use the biggest dia prop that will fit!!  :D

Dan


I have known Steve Bennett owner of Great Plains for years. One sharp fellow.

To quote his web site:

"The NEW Series 3 Reduction Drive is available in drive ratios
from 1.6:1 up to 2.5:1. Props used vary from 72 inch x 40 inch
pitch up to 96 inch x 56 inch pitch. It greatly improves the take
off and climb performance of any high drag VW powered aircraft
that needs more thrust."

"On a 2180cc engine with a 1.6:1 drive and a 72 inch prop,
you will see about 350 lbs. of thrust. On a 2.0:1 drive and
an 84 inch prop will pull about 450 lbs. of thrust. You get
the idea! (A direct drive VW with a 62 inch prop will pull
about 215 lbs. of thrust.)"

Static thrust is not the whole answer but you get the idea.

Paul Lamar ...No rotor no motor.

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