ChristianGott

Can anyone refresh my memory.....

What are the benefits and disadvantages to spinning props inward as opposed to outward on a twin IO non-surface-driven V-hull?

Thanks.

Pat McPherson

Hi Chris, How are things?
Spinning the props in will give you more bow lift.
Spinning out will give more stability and make the boat easier to maneuver around docks.
I think on your boat more bow lift will gain you some speed.
What props are you running?
On our old 28 Cig. 3 blade Mirage were the best...

I had it backward...

JaayTeee

Do a "search" on prop rotation.

It's been discussed here before .

Different people have different Idea's on the subject.

My experiences are out ='s stern lift, in ='s bow lift

jt

ChristianGott

Hey Pat..
I spin them in right now, but the props themselves are designed for lift (Revolution 4's) I know the Sutphen has a heavy stern. Can you have too much stern lift? What would the effects be? Chine walk?

I have an odd handling quirk I'm trying to eliminate. Borderline walking...even with minimal trim, and tending to want to go to starboard at high RPM. I wonder if the props can be "diffferent" from casting flaws. Maybe I'll switch them and take a ride tomorrow, so the question doesn't haunt me all winter. Maybe I'll have them blueprinted over the winter.

Thanks guys.

Pat McPherson

I think I did have it backward... IN=more bow lift.
We ran our 28 Cig. with outward rotation and she handle like a dream.
I am not sure 4 blade props are best on the older style deep V boats?
The drives on our Cig. were deep and 3 blades were a lot faster.
You may want to try a set of Mirages before you put $$ in you 4 Blades.
I would ask the same question in the Sutphen forum...

ChristianGott

Thanks Pat...

My props were originally designed for high horsepower, heavy stern, outboard boats. You know the "black magic" involved in prop selection....mine were revamped for the alpha drive, due to its horsepower and not its torque. My cruise is sweet...3200rpm=52mph. That's mostly my thing. My old boat, like yours, hauled tail on a well balanced , well propped single engine. I had confidence in it.
Tomorrow I will try the 4 blades rotating the other direction, and the old 3 blades spinning both ways. I should be a model of data, or a mentalcase, by 4:00pm tomorrow (today)...
Thanks again.
C