14.5 x 17 Stainless vs 14.5 x 17 aluminum (3 blade)

[Glenn Iverson]

I f I replaced my 14.5 x 17 aluminum with a stainless to improve hole shot to get skiers up quicker can I keep the same pitch or do I need to drop to 16 or 15? The aluminum will do it but it struggles. 19ft. 2500 lbs. bowrider with OMC 5.7 Usually 3-4 people in the boat when towing.

 

[alldodge]

The aluminum will flex more under heavy load but the 5.7 doesn't produce enough HP for the small amount flex to make any difference.

The aluminum prop has wider blades the the SS so it takes more HP to turn but the SS prop weights more. Over all I like SS over aluminum but not sure your going to notice that much of a difference changing.

I have a 21 and a 19P props. If I want to get someone up fast, I'll change to the 19 and just watch any WOT because it will over tach

 

[QBhoy]

For me...and in Simple terms...it all depends on the particular stainless you get. In simple terms...if going from like a standard black max 14x17 (approx dimensions) to a vengeance run of the mill 14x17 stainless...you can and will most likely see a drop in holeshot and occasionaly even top end too. They a like for like in their cut and dynamics.
But at the other end of the stainless props...things like tempest, enertia, the old trusty laser 2 and a few others, when like for like same pitch as an ally, can and will often be that good, that you don’t need to use the old archaic idea of having to drop a little pitch.
just my thoughts.

 

[harringtondav]

I'm in AD's camp. You can't fix a power issue with prop material. Lower pitch = better hole shot. But use the right hand to limit WOT rpm.

 

[Texasmark]

QBhoy mentioned the old reliable Mercury Laser II. He has/had/works with boats like yours and for him to mention that prop brings me to my comment. The Laser II is ported. I have picked up on different comments about ported props and I/O propulsion units but here's the point. Ports, holes under the leading endge of the blade, with different sized plugs for "tuning" the port are just what you want for a super hole shot and fast WOT performance. I tune my holes for about 1k rpm increase at "hammer down in the hole" to get the rpms up fast, getting the HP to the prop shaft fast for the thrust heeded to get out.

Once up and running, at some point, the oncoming water pressure seals off the holes, in some cases you feel a bump due to the increased thrust, and off you go. With this type prop, you tune pitch for the WOT recommended rpm range where you like to run....I like top end or a bit higher, and let the ports in the prop get your hole shot. BTDT