left or right hand prop performance.

[markcw]

Just noticed tonight after 2 years that my propeller on my V/P 290sp leg is a left hand and not a right hand prop, and just wonderd is there a difference in performance in handling on a left hand prop/

I have also recently fittied a trim fin anode on the leg just above the prop, but on recent visits to boat yards when working i have seen 290 sp legs with none fittied, i brought the boat with one not fittied to the leg just the hole, i know from the manual that its set a 5 deg max but is there any point in having one as all the other anode on the leg have all been replaced in the past winter.

mark
wellcrafty

 

[MapisM]

You're actually asking about two completely different things.

Let's start from the fin anode, which is easier.
That is only meant to equalize the effort required on the steering wheel if the boat doesn't have servo steering.
If she does, you'd better fit an anode anyway, but with no fin.
If she doesn't, and you feel on the wheel that the boat tends to steer to port (with a l/h prop) unless you constantly contrast such tendency on the wheel, that's a situation which the fin anode can correct.
Just fit it at 5 degrees or so and experiment a bit till you feel that the steering wheel is neutral. But mind, with a L/H prop you must actually fit it at minus 5 degrees, looking at the cavitation plate from its bottom.

The other point re. whether a single engine boat performs better with a L/H or R/H boat is more tricky.
The standard choice of using a R/H prop is due to the fact that this compensates the torque effect of the engine crankshaft, which tends to make the boat list to stbd when accelerating (whilst a R/H prop does the opposite).
But there are also other factors to consider.
The bottom line is that if your boat is fitted with a L/H prop, and you're not experiencing problems of leaning to stbd, then that is the right choice.
With regard to handling, the only difference is that while maneuvering your boat will steer more easily to stbd, both in fwd and in reverse.
But a R/H prop would be equally asymmetrical - the boat would just steer more easily to port.

 

[markcw]

great answer MapisM thanks alot, if i can rcall when on the boat there is a resistance on the wheel to right side but very easy to turn to the left. so i may have to play with the fin abit, its set at -5 at the mo.

just wanted to ask as i was thinking a getting another prop as a spare and thought to get a r/h or another l/h

mark

 

[rafiki_]

great answer MapisM thanks alot, if i can rcall when on the boat there is a resistance on the wheel to right side but very easy to turn to the left. so i may have to play with the fin abit, its set at -5 at the mo.

just wanted to ask as i was thinking a getting another prop as a spare and thought to get a r/h or another l/h

mark

I don't think it is quite as easy as replacing a RH instead of LH prop, as your sterndrive is clearly geared for a LH prop. If you fit a RH prop, then when you shove the throttle forward, she will shoot off in reverse.

 

[davedpc]

With a lighter craft the tendancy with a standard prop is to lift the boat against the weight of the helmsman. This is an advantage when initially blasting out of a hole at full beans but this reaction would be cancelled out by the equal weight of a side by side passenger. This i think is why the helm position is usually on the starboard sideof lighter single screw powerboats.

 

[MapisM]

just wanted to ask as i was thinking a getting another prop as a spare and thought to get a r/h or another l/h

Well, if normally your boat does NOT list to stbd, it means that she's well balanced for a L/H prop, and with a R/H prop she would surely list to port. By "normally" I mean with a distributed load and no crosswind. In other words, if the boat rides neutral unless there's some "external" reason that make her listing, I wouldn't waste time with a R/H prop.
Besides, rafiki is correct, you should also reverse the throttle somehow.
I don't know IF and HOW that can be done with a VP290.
There are outdrives where that's actually impossible (Merc Alpha), because you would destroy the gearbox, and others (Merc Bravo) where it's just a matter of switching the cables on the throttle.
IIRC, no VP outdrives have the same problem as the Alpha, but don't take my word for it.

My choice for a spare prop on a boat like yours, unless as said previously there are reasons to try the opposite rotation, would be for a slightly longer/shorter prop, depending on the boat usage and on the results achieved with the current prop.
If with the current prop you can go above the max rated RPM at WOT, you definitely want to try a longer one.
If with the current prop you can't reach the max RPM, you should try a shorter one.
And even if the current prop is perfect (i.e. you can JUST reach the max rated RPM, with a light load), you might still wish to have a shorter prop for towing toys and/or cruise with higher load.
Horses for courses.

 

[markcw]

the V/P 290 s/p legs can be reversed in the gear houseing via a cable linkage reversal.

no issue with boat speed, full on but dont use it for that, 53 knots max but to fast for my likeing and wifes, happy just cruising, i just wonderd if there was a difference in performance, looked at the v/p manual and its standard with a L/P prop, so will keep it standard,

 

[MapisM]

Blimey, do you really mean 61mph on a 20 footer?
I can understand your wife's concerns, she must be a handful to drive at that speed...
By "she" I mean the boat, obviously!

 

[markcw]

yeh wellcrafty is a pretty fast boat but also is the fuel consumption at that speed, and put her in the wrong postion and like any boat at that speed its gonna flip.

well thanks all, thats another topic you have all answerd for me

its stays with a left hand prop.

now going to do a service on the leg before our outing next week if weather permits.