Stainless Steel Prop

bubbless

Cadet
Joined
Apr 24, 2004
Messages
10
Will I notice an improvement in performance if I switch to a stainless steel prop? I have a 115hp Mercrusier that I use to pull a skier.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Stainless Steel Prop

hello<br /> if the prop your currently using is of the correct diameter and pith that allows for proper rpm at the load your pulling then probably not.<br /> for a 115 general use pulling skis I would save my money and buy gas not props.<br /> good luck and keep posting
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: Stainless Steel Prop

A stainless prop issn't where I would put my money for better hole shot for skiing. A lower pitch prop and a hydrofoil or smart tabs is where I would focus my attention and dollars.<br /><br />My ski prop is on my 3.0 is a 14" dia. x 17" pitch aluminum which gives great bite in turns and very good acceleration. My running prop is 13"dia. x 19" pitch stainless which is slower on the take off, but gives me a slightly higher top end.<br /><br />I also have a Stingray hydrofoil which makes the boat jump on plane in 1/3 the time. This inexpensive device really makes a huge difference in hole shot. (I hear smart tabs work great too.)<br /><br />So, in summary, pitch down a couple of inches and get a hydrofoil or smart tabs and you will notice a huge difference.
 

Northern Eclipse

Senior Chief Petty Officer
Joined
Jun 24, 2003
Messages
665
Re: Stainless Steel Prop

If its a better holeshot your looking for stick with aluminum and go down a pitch, SS props are more beneficial at high speed since they tend not to flex. I run a 21p ss for cruising and top speed and a 19p AL for heavy loads and skiing.
 

Cobra SX

Seaman Apprentice
Joined
May 4, 2004
Messages
33
Re: Stainless Steel Prop

hey guys<br /><br />I have a 1995 OMC Cobra SX Stren drive on a 20 foot sea swril. I have a 302<br />Ford V8 (5.0) inside. (Runs very strong) <br />my W.O.T. opertation range is 4200 - 4800 . I put a cavation plate on it<br />this year and really started to note<br />that i was running at 5,150 and RPM were rising a little bit more. So im<br />out of the Range this hurts my MPG<br />and the fact that i like to Cruise at top end more than pulling skiers ,<br />boats , etc... i want to go faster !!<br /> <br />Im running the Stock alum prop ( 15x17 ). top speed aprox 39 mph at 5,200<br />rpm (400 rpm out of range)<br /> <br />I relaize i need to change to at least a 19 pitch. But i do alot more<br />Crusing at 80% throttle or more.<br />So i would like to know what STAINLESS steel Props would Be best for my SX ,<br />i have heard that on the<br />SX stren drive you can gain 5-10% more power JUST by opening the Exhaust<br />Flow out of the Prop and bellows , RIGHT ?<br /> <br />I want this boat to be more of a top end crusier that CAN get better GAS<br />MPG. and have a higher top speed.<br />Thats why i wondered how a stainless prop at pitch 21 would do in my case<br />cause by theory i would still be at<br />about 4,400 rpm WOT fully trimed right?
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: Stainless Steel Prop

My experience has been that when changing from aluminum to stainless, that if you went to a stainless 15 X 17P you would lose about 2-300 RPM. If you went to an aluminum 19 you would be about the same, 2-300 RPM less than you are now, you probably need a 19P with a stainless and a 21P with an aluminum. I do not think you can spin a 21P stainless.
 
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