Octura 1475/2 modified for top speed   

The Octura 1475/2 has recently become a hot prop among many GAS racers

and fast runners. It lends itself well to modifications that produce

high speed, with many different surface drive applications such as,

gas monos, cats, hydros, and riggers.

It comes stock at 2.95"dia x 4.13"pitch, aspect ratio (1.4).

Reducing the dia to 70 > 72mm and increasing the average pitch

to 5.5" with a  max pitch of 6 > 6.3". Will allow this prop to really turn-on,

with the higher aspect ratio of (1.8). Depending on the setup, if some lift needs 

to be removed with "monos" & "cats", back-cut the trailing edge about 1/8th" at the hub, 

tapering to zero at the tips. A tapered back-cut also increases blade rake. 

The entire leading edge should be contoured from tip to hub,

while removing the tongue Area. The blade tips should be spooned or concave shaped, to add cup,

reduce lift, and condense the thrust cone. This redirection of thrust further aft,

enables increased forward push with less slip. This increases peak RPM and top SPEED.

For best results, always thin, sharpen, balance, and polish to a smooth finish.

Note:  Rolling the edge, removes most of, if not all the lift. This causes the transom to be pulled down

somewhat, which requires a deep strut setting to keep the nose down. This lower prop setting greatly

 reduces Slip, which is our single worst enemy. By reducing Slip we increase prop efficiency during it's 360degree

 revolution, resulting in faster top speed. 

                                                          Paul Govostes 2-24-03                                               Back

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