prop pitch question

[Fergus]

I have a new Volvo d2-40 installed witha folding prop. It has had intermittent problems properly engaging forward gear since the beginning - it has had a new clutch pack and various SD oils have been tried. The installing engineers are now saying that because the prop is over-pitched (max revs in gear 2200) this is what is causing the engage-forward problem. How can this be? Would love an explanation!!

Thanks

 

[sailorman]

what is its rated continuous rpm

I have a new Volvo d2-40 installed witha folding prop. It has had intermittent problems properly engaging forward gear since the beginning - it has had a new clutch pack and various SD oils have been tried. The installing engineers are now saying that because the prop is over-pitched (max revs in gear 2200) this is what is causing the engage-forward problem. How can this be? Would love an explanation!!

Thanks

 

[savageseadog]

Are you absolutely sure that the blades aren't jamming.

 

[Fergus]

Yes - quite happy doing 7kn at 2000 rpm!

 

[sailorman]

thats all very well but what is the rated rpm ( RU an MP)

Yes - quite happy doing 7kn at 2000 rpm!

 

[Fergus]

Afaik 3600?

 

[sailorman]

Way over propped then.
my engine is rated @ 3000 RPM WOT we get 2850 PRM @ 7.5kts.
cruise at 6.5kts @ 2000 RPM, 7kts @ 2400 RPM

Afaik 3600?

 

[Fergus]

So what's the answer re; the gearbox problem pls?

 

[sailorman]

No idea re box but the prop needs adjusting or changing, as you were supplied with an incorrect pitched prop

So what's the answer re; the gearbox problem pls?

 

[richardbrennan]

Not sure who installed it for you, but I had a new D1-30 installed last year and a sea trial was required to test the max RPM was within certain limits (I think 2800-3200) before the installation was signed off and the warranty thus valid. Is it a Volvo prop; it's probably also worth checking the gearbox ratio supplied?