kcsteve124

I am looking at a 1990 38 Top Gun with 900s and six drives,I have always been told that for straight bottoms you turn the props outward for bow lift and for step bottoms you turn the props inward for ass lift. My question is what is the real story? The owner turns them inward and gets plenty of bow lift but it doesn't hadle as well around the docks, so does it change speed on the boat one way or another? Thanks for the help.

bigfarmer

Spinning inward will give you a few mph more, but might cause your boat (flat bottom gun) to porpoise. Spinning 4 blades in will give you bow lift and 5 blades will give you stern lift. ive never really noticed the difference around the docks as some guys claim. My boats attitude was always a bit better spinning outwards. Ive swapped rotation many times and i guess its personal preference.

MILD THUNDER

iTrader: (3)

IN=Bow Lift. OUT=Stern lift.

In is usually a tad faster, but sometimes reversing around the docks and what not can be tricky.

Griff

x2

kcsteve124

This is the boat I was referring to when I asked the question and he is spinning 4 blades. http://www.offshoreonly.com/classifi...o44938-en.html

bbladesprops

MILD THUNDER and Griff,

You guys have definitely been paying attention over the years.......
5-6 years ago, it was uncommon for anyone to answer this question on here. What a great tool this thread has become.

However, rules of thumb are made to be broken. Not the basic physics, but definitely from a seat of the pants preference side.

Nice job guys!

Brett

kcsteve124

I know I'm very impressed and thank everyone for thier answers to my question.

MILD THUNDER

iTrader: (3)

Thanks Brett !

pqjack

maybe the ONLY thread without bashing or insults...let's keep it that way...

kragar

Why is it tricky around the docks when props are turning inward? Debating trying on my boss 302.