Prop pitch

[alruss]

Looking for older petrol head with good memory. I have volvo 115/ 120 hp.dating back to the mid sixties,( B20's) with 100 drives. Am able to rev. quickly to 4000rpm with very good acceleration and top speed of 20knts. Present props are14" x 12. My inexperienced thoughts are, I am at the end of the power band on the engines, and accelerating to quickly. I feel a coarser pitch would reduce my revs at top speed and reduce the speed of acceleration of the engines. My final worry is the torque rating of the outdrives, Volvo never used more than 130hp on 100 legs would higher pitch produce to mutch torque?
Thanks in antisipation. alan

 

[Its_Only_Money]

Don´t know your exact engines but you need to know the max rated rpm - if that is 4000 and that is what you pull flat out then you have the right prop pitch already, if the rated rpm is lower than you are pulling flat out then you may be better with a coarser pitch - from memory and it depends on the leg gearing but a 2in change in pitch equates to approx 400rpm or so.

Changing the pitch won´t create more torque, that is created by the engine and won´t be altered by a change in prop pitch so no worries there.

 

[omega2]

www.clementsmarine.co.uk, will be able to assist. no connection, ask for Paul Williams.