Stainles vs Aluminum vs Piranha prop performance

Bill Burruss

Bill Burruss

Well-known member
All,

I'm in the market for a new prop (could just be a spare) for my 25 hp Yamaha. The stock prop is usually running 5800-5900 rpm w/me in the BB2, so I believe it is the correct pitch. Was wondering if a stainless steel or piranha prop would offer any more speed (perhaps be achieving more efficiency) than the OEM prop. I know the stainless is much more durable, and the piranha has the advantage of easily replaceable blades, but do any offer a speed/performance advantage given that the pitch is right?

Thanks,

Bill
 
Bill

Yes. Most SS props have cup in them which enhances performance. Cup supposedly adds the equivalent of about 1/2" pitch without taking an rpm hit from what I've read and been told by the local prop shop. Also the blades are thinner resulting in a tad less resistance. You may or may not be able to notice the difference but you certainly won't take a hit in performance if you go with SS.

Hows the new boat project coming?
 
Eric,

Thanks. I have noticed a slight drop in speed, and am thinking it is probably the dings the original prop has picked up over the last 70 hours. Am always looking to pick it up a little.

The new "decoy sled" is coming along. The outer hull is glassed/epoxied, and I just started glassing the inside today. Hope to finish glassing and the second coat of epoxy on the inside tomorrow. The weather's nice, and there are very few birds here right now.

How's your season going?

-Bill
 
Bill

Our season is just getting started. Nothing all that great so far. I've only been twice. Spent today doing more scouting that hunting. Never loaded my gun but saw some areas that may hold some birds later in the season.

Keep the pics of the boat project coming. That looks like one really cool little boat.
 
Bill,

I've run both aluminum and a Piranha prop on my 30 Evinrude for my BB3. I don't think there was any difference in performance between the two. Changing blades was definately easy with the Piranha but the aluminum would run longer bent than the piranha did with broken blades. When the blades broke on the Piranha they broke very close to the hub and didn't give me much in the way of forward motion after that. After hitting stumps just about everytime I was on the Mississippi this year I am considering going to a stainless prop. The guides on the river run stainless so the stumps aren't nearly the problem they are for anyone running aluminum.

Pete
 
One consideration when choosing props is that when you switch to a stainless the prop is no longer the weakest link in the drive. That has now moved inside the gearcase. Just another opinion. The blades are thinner resulting in a better efficiency (speed) but between price and the weakest link part you may want to rethink stainless for a duck boat. I use one on my fishing boat but not on the duck motors. I have never used a Pirahna so can't speak to that one. Stainless will plow through the slop w/o bending though. Lots of factors, good luck.
 
You're right Tom and that was always the one consideration for not putting one on a duck boat. Have you seen damage inside the gear case caused by being the weakest link? I was lucky this year and only went through one aluminum prop but now the one that is on there is really trashed and I doubt can be salvaged as there are chunks missing. I hate to spend $200+ on a SS prop but spending $60-$80 a year for aluminums isn't fun either.

How's the back?

Pete
 
The old wives tale about a stainless prop being more risky than an aluminum prop has got to end sometime, right?

All newer outboards use props with rubber "cushions" between the blade assembly and the hub that attaches to the propshaft. This does a very good job of absorbing shock and preventing it from damaging your propshaft and lower-unit gears. Of course there are guys that can seemingly "f***" up a bowling ball, so nothing is 100% guaranteed, but as long as you're careful and don't hit a boulder at full throttle a stainless prop is the way to go on a duckboat.

I used to listen to guys say that I should run an aluminum prop on my duckboat motors, but after $1000's spent replacing damaged seals from unbalanced props caused by bent prop blades, and actually replacing 2 or 3 props every season, I finally decided to go stainless about 10 years ago. Still running the same prop and never had any damage to my lower unit. And I've even hit rocks with it. The stainless props just shrug off low-speed strikes that would bend or destroy and aluminum.

There is a reason that the guides all use stainless props, because they can't afford to mess around with aluminum props!
 
Pete,
The back is fine as can be, no real problems. Got to get in shape for next year now. And try to act my age. My new pup Booker T is really shaping up to be a good one if I don't spoil him. I still miss Walker but he is waiting beyond for another boat ride. Hope all is well with you, sounds like you got into some divers and hot food.
 
Bill, this was a great subject. One that I've been contemplating for a while now. My aluminum prop realy takes a beating and needs replacing at least every other season. I'll take everyone's advise and make my decision at the end of the season. Good luck with your decision. Kevin
 
All,

Thanks for the replies. They really helped me with my decision. I'm going to ask Santa for a stainless prop for Christmas : )

-Bill
 
Something about "the old wives tale".....sure, there is a rubber hub that acts somewhat like a shock absorber...the aluminium props that break blades off do so usually without spinning the hub. That tells me that the hub takes a tremendous amount of force to spin putting considerable torque on the guts of the lower unit. The lower unit has gears with teeth, not clutches and bands. If I hunted an area that destroyed aluminium, I would use Comp Props..and did till I sold the motor that I had one on. It was tough as hell and hit plenty of stumps..not so many rocks. Just something to ponder.
 
I am not positive, but I think a good prop shop can refurb a prop even with chunks missing. They're inexpensive enough compared to a stainless prop that I'd buy a new one and keep the old for a spare. Hey, that IS what I did. LOL
 
I did a lot of river hunting and back water hunting in the late 80s through today on the lower Ohio around the confluence of the Mississippi...I have a 40 HP Nissan/Tiahatsu...The props I always bougth was called a Hustler (aluminium) always had three props on hand...Two spares in the boat and one sent to my the local prop repair man if needed ($14.00 a shot, typically once a year) They come with a quick change connector and I always keep a few spare nuts and cotter pins. The props ran around $60.00 and i am sure they are more slightly more now but in comparison to a $170 to $240 prop for the same motor you weigh the cost. But the issue is that the aluminium props would shear or tear before any damage was caused to my lower unit. If you have any chance of hitting riprap/rocks, logs, and any debris while running the aluminium would be sacrificial compared to the stainless. If you way the cost of having a spare prop in the boat the aluminium seems more feasible unless your wallet is deep...I never went without a spare prop in the boat no matter where I was hunting...
 
Most new aluminum props are in the $100+ range nowadays. Most prop repair shops charge at least $50 to repair a damaged aluminum prop. Two new aluminums and a couple of repairs a season and you're already over the cost of a new stainless.

Aluminum makes a crappy prop material. It's just TOO SOFT. Even low-speed strikes can bend the blades, which can result in an unbalanced prop and will tear up your propshaft seals. Costing you another couple-hundred $$ if you take it to a mechanic.

I wasted a lot of money on aluminum props and all the trouble they cause. I'm still using the same stainless prop I bought in the Cabelas Bargain Cave for $125 over 10 years ago. No problems with my lower unit yet, and I've hit a LOT of stuff, including rocks with it. I'll always opt for a stainless prop, especially on anything 25hp or larger.
 
Bill,
Get a SS, you'll wonder why you waited so long. I ran Alum for way too long on my BB2. I'm pretty hard on my engines and props. I went through 2 alum props a year - at least. Used to get them from Cabelas (MI Wheel ex hub) for around $80, but this summer best I could find was OEM for $125! I hunt the rivers and you just expect to hit at least a couple logs/stumps every day, not to mention spots that have so many rocks you feel lucky if you only hit one in a day. I tried a comprop this year and it was deteriorating just from some sand/mud after 1 hunt, can't imagine using one of those in a rocky area. The first Alum prop this year didn't make it through the second week of the season. Two weekends, two props dead. So I decided to finally try a SS, it made it the rest of the year (25+ days on the water). It has hit countless logs, stumps, and rocks, been run through the mud and sand and it is still in great shape (you don't want to buy an engine from me - I wouldn't!). At this rate, I bet I'll get at least 3 years out of the prop.

I'm running the Cabelas SS 10 1/8 X 12 on a 25 Evinrude, and I did also realize some performance gains. Didn't a huge difference with a light load, but I'm able to haul a pretty good load and don't feel underpowered near as often. If I could just get a little more power I'd be set. I still need to order the parts and try the mods as Lee suggested to convert it to a 35 - one of my off season projects.
 
Dan,

Which SS prop did you get (brand)? I see a Solas on iBoats on sale for $155. Haven't seen anything cheaper.

Pete
 
The one I got is the Cabelas brand prop. It goes for $209, $155 is pretty good, the other ones I found were in the $250 range. I might have to get one of the Solas props and try it out to have for a backup.
http://www.cabelas.com/...e=pod&id=0000980

Are you still getting Alum props for $60 - $80...? Where?
 
Last edited by a moderator:
You must log in or register to reply here.
Back
Top