Boat Question???

[TORQUE THIS]

Is there a noticeable difference switching from an aluminum prop to a stainless prop?



I need to pick up a spare before boating season starts, just can't see spending all that money if there are no noticeable differences.

 

[cdpsrjc]

I think so... I paid the extra for stainless because it's harder than aluminum. In the event you strike an object under the water, you are far less likely to tear up a prop. I've seen a few aluminum props with small chunks out of the blades, never seen a stainless one in that condition. I had the stainless one double cupped while I was at it, gave me better low end hole shots. Did the stainless thing at purchase, put the factory prop in the box and keep iit in the boat as a spare. Never needed it. Good luck and be safe. Larson 226LXI 5. 7L Volvo drivetrain. Pleased as punch with it and the CTD pulls it like a dream



Richard

 

[Champane Flight]

Depends.

It depends on what your looking for. If you go with a stainless performance prop with different pitch or a cupped prop to suit your needs (different pitchs and cupped for holeshot performance or topend) . The difference in materials is flex. The alluminum does flex more than your stainless, therefore loses some of its pitch or performance with high HPs. The Stainless does not give, which means it will not break under most strikes. This gives you another problem. If it does hit some imovable object underwater, it may take the lower unit with it! So instead of paying for just a prop, your paying for another lower unit... ... ... . The difference in performance can be done with a change of pitch or cup. I would not go stainless because of higher cost and liability, unless I was ocean going or full out racing. Talk to your local boat people and they can steer you in the right range of pitch or cup for your performance needs.

 

[Rammin On]

Champagne Flight is right on target!

 

[BCFAST]

CF is on target... . if you do a pitch change, be careful. My b. i. L. has a fishing boat with twin CATs in it... they changed the props a few times and LESS pitch ended up giving him better top speed and economy!! I would have bet against that..... and lost! I guess it depends the engine's rev range.

 

[LSMITH]

I run a stainless prop on my duckboat because it is always in the mud and sand and rocks, it is not uncommon for me to have 1/2 of the prop running in "solids". Logs and stumps are pretty common too. I went through 2 aluminum props in one season before I paid up for a stainless, and have had to have it rebuilt once in two seasons since for the same cost as a new aluminum prop. The stainless are rebuildable where the aluminum are not, missing material can be welded up and reground and bent blades can be straightened. The aluminum will break blades off where the stainless will pop a shear pin. A dozen shear pins in the boat is no problem, two extra props is. The stainless makes sense in a rough environment to me. I also picked up about 4 MPH with the stainless in the same pitch as aluminum with a holeshot/heavy load type prop.

 

[TWeir]

Love my stainless…



I changed to a stainless 4 blade and love it. . We run up to 40+ miles offshore looking for Halibut and Tuna.



It changed the way my boat handled and lowered my gallons per hour. Check with your local Mercury dealer they have demo props that you can try before you buy. I don’t know if Mercury will fit your Volvo but it may be worth looking into. I also run a 5 blade at times, this is one smooth prop! Better for inshore waters. If you do change props make sure that you stay within your recommend wide-open throttle RPM range.



Good luck

 

[maint.man]

LSMITH, I beg to differ, I've got a aluminum prop on my ski boat, and have had it repaired twice . Both times there was a substancial amount gone off of one or two of the blades. However , I have been thinkin' about a stainless , and am a little in the dark on the "shear pin" thing . How is yours set up ? Brand ? I've got a Alpha one lower unit (inboard) and my stock prop is just on a splined shaft . I have been looking at a set up where you buy a hub (stainless or alum. ) and then you can just change the prop housing (stainless or alum. ) and the alum. housing is only a 60. 00 replace and it is a polished unit . Last prop repaired was the same money. Any thoughts?

 

[LSMITH]

Originally posted by maint. man

LSMITH, I beg to differ, I've got a aluminum prop on my ski boat, and have had it repaired twice. However , I have been thinkin' about a stainless , and am a little in the dark on the "shear pin" thing . How is yours set up? I have been looking at a set up where you buy a hub (stainless or alum. ) and then you can just change the prop housing (stainless or alum. ) and the alum. housing is only a 60. 00 replace and it is a polished unit . Last prop repaired was the same money. Any thoughts?

Maint Man, the quality of a rebuilt aluminum prop is not nearly what a new one is, they can be rebuilt but most prop shops are not big on it at all. I have only found one shop around here that will even do it, that is what I use for a backup prop. It works but that is about all that can be said for it. A stainless prop can be repaired to as good or better than new. My stainless has been repaired by the same shop and is better than when I bought it. My old boat has shear pins in the prop shaft rather than a splined setup, if the prop hits hard it breaks the pin and the prop spins free on the shaft. My new boat has a rubber bushing inside the prop, between the prop and the hub, that is supposed to take the hit and slip a bit if needed. The rubber bushing is actually really nice, it takes a change your shorts hit with no problem. I am running Johnson outboards on both. The props with replaceable blades are also catching my eye, but stainless is the best for the application I am using them in. I intentionally run in 8 inches less water than what my boat needs to run good in all the time, logs and stumps are a fact of life, and I may be a long way from anywhere so it needs to get me home no matter what. I have spent an hour with the prop in the sand and mud before, the aluminum is gone by then end of the trip from the wear and stainless is just really shiny



I can tell all of you one thing, buy a GOOD stinless prop that fits what you do with your rig and you will not be disappointed. They are a world better than the best aluminum in all aspects of operation.

 

[cdpsrjc]

Torque,



I'm not running around area lakes looking for stumps or sandbars and I doubt you are either. The stainless I got was the same size and pitch as the OEM. SS came cupped and has worked well for me. I hit a stump just under the water at about 40 MPH one time, scared the crap outta me. Lower unit kicked up and over, went back down into water and kept diggin. I shut her down fast and went swinnin for a look. No damage to hull, prop or lower unit. Lucky... very lucky. I don't know if an alum prop woulda bent, but sure SS one did not. Had a nick(no missing metal) in trailing edge of one blade, and I peened it out when I got home. An out of balance or bent prop will tear up lower unit seals in a heartbeat. I'll bet that's why you're looking for a spare. We wouldn't consider driving without a spare tire, but most boaters don't have a spare prop Put a stainless on and swap the old to the spare. Keep pitch and dia same unless you're after better performance and have expert advice.



Happy Boating

Richard

 

[TORQUE THIS]

Stainless!!!

I think I'll go with the stainless!



I run in a tidal river, where I launch is salt water and at low tide it is very difficult to get back to the ramp, lots of mud and small rock, it really tears up the aluminum prop.



After launching, I run up river where it is fresh water, all mud / sand where we anchor and play. Lots of floating debris on the river too, really bad after a rain storm. Most debris is branches, stumps.



What ruined my aluminum prop is the low tide trying to get back into the ramp, and hitting debris under water.



It sounds like the stainless will hold up much better for me.







When I took my safe boating class, the instructor was a harbor master in Bridgeport. He always refered to the prop as a 3 bladed depth finder!!!!!

 

[midnight1black]

Stanless

Oo. I also run with a stanless High Five 17 prop, it works the best one for my needs while playing on the ski's Note! I only use it on the mountain lakes. I change back to alum. 19 pitch

at lower altu. Good luck and happy boating.

 

[DEZLPWR]

Stainless....

The only way to go IMHO. We have a 1992 Bluewater Riviera with a Mercruiser V6. It came with a 21" aluminum prop. We switched to a Mercury LaserII 23" stainless and gained about 5 mph on the top end with only a little less hole shot. The 21" aluminum is now our spare!

 

[DLeach]

Warnings about stainless

Anybody who has picked up a stainless and an aluminium prop can tell a big difference right away, WEIGHT! Swinging that extra weight around does several things. First thing is most people think that they can go from say a 14x21 alum. to a same pitched stainless and achieve the same results. True,unless your boat is even a small amount under powered. If anybody has just turned a alum. and stainless prop by hand on a boat out of the water. It takes a substantial amount of energy to get that stainless moving. That equates sometimes to a slower hole shot with a stainless. No amount of repitching or cupping can overcome a underpowered boat. 80 percent of the time, a stainless prop only makes matters worse. On the subject of striking objects under the water, while a stainless will hold up alot better with hitting small objects, light brazing of rocks and stump, i would rather let an aluminium take the shock instead of my L/U. The days of shear pins are almost gone, and dont buy into the rubber hub absorbing some shock either. I have seen too many people get sick of replacing alum. props and go to a stainless only to come back and have there clutch dog tooth or a pinion gear tooth chipped. If you think a 90 dollar prop is bad wait till I have to tear into and reshim your L/U. Now with all the weight your spinning around at cruising rpm, that stump you whacked earlier that morning while launching is now sending vibrations through your propshaft. All the while your thinking, "thank god i bought that stainless prop", it is now causing bad wear patterns on all your gears, foward,reverse,pinion, not to mention bearing and eventually seals. Vibrations that you cant feel, that get soaked up by your gimble housing or transom shield depending on your make and model. To make a short story long

if you have a reasonably powered boat, are never in water less than 12 feet deep, or spend most of your time at cruising speeds get the stainless, if you however are one that is known to use your prop as a depthfinder on a regular basis, have a underpowerd boat and stay close to shore, do yourself, your L/U and your favorite mechanic a favor, stay with an aluminium.

There isnt that much money in selling props, the real money is in labor in rebuilding and reshimming you L/U!



Dustin Leach

OMC Master Outboard and Sterndrive Tech

Mercury Mastertech

Volvo Penta Gas and small diesel S/D tech



Aloha

 

[DGFoster]

I can tell you there are pros and cons to both.

An aluminum prop flexes and you will lose some performance with an aluminum,but also if you strike something underwater with an aluminum prop you are less likely to damage your lower unit because the prop will break before the lower unilt will,which will cost you BIG bucks for lower unit repair over fixing or replacing a prop. Now with the Stainless prop,will will gain performace as long as it is the right prop for your boat,but if you hit something the prop is let likely to absorb the hit and it may distroy your lower unit. Big money. But also is replacing a stainless prop expensive.

What I do if I am on a lake that I know I wont hit anything I use the Stainless prop,but if im on a lake or river I don't know very well I use the aluminum prop,and there are a lot you can do with the right stainless prop like cupping the blades gives you a better bite in the water,and have some vent holes drilled to get the prop to spin up faster.

Good luck and happy boating