|Who has a stainless prop? I have gone through a couple of NiBrAl props, due to some fist-sized rocks near our launch. Would the same impact on a stainless prop damage the drivetrain? |
|I am to worried about rocks, logs and anything else that I might hit with my prop. A stainless prop is not forgiving at all and the impact may very well damage your drive unit. Also sainless can't be repaired as far as I know. Better performance from a stainless prop but at a potential cost.|
|stainless can be repaired, but it will cause more damage to the drive components since more of the impact will be transferred to them due to the prop being stronger. |
I would rather keep paying $100 to repair my NiBrAl prop that much more to replace a shaft and/or tranny.
|That is the way I have been leaning. The part that really stinks it that both times I have damaged it, It has been in reverse. Evidently that is harder to repair. |
So even a smallish impact can have dire consequences with a steel prop?
|SS is a pain to repair, that is why it is more expensive to repair. |
I have two props and I switch them when I ding it and send the other one in for repair. I do, however, have the advantage of being an Acme dealer.
From the performance perspective, you will gain very little on most boats with SS from a CNC machined prop. IMO, it is not worth the price for most people.
|I've had two "smallish" impacts on an SS prop without driveline damage. Without going into the details, let's just say that you have to careful when puling into a slip with a submerged Hydrohoist lift. |
Here's the result (and remember, SS is tough stuff). This happened well over 140 hours ago, with no evident damage other than to the prop itself.
|I ran a SS 4 blade oj for 2 years. Loved the performance of this prop. Towards the end of last year when water levels were low, I decided to switch to my nibral backup prop. wouldn't you know it, I hit something hard. Screwed up the prop. Not sure I will put my SS back on the boat because I would rather save my running gear. If you are always in a fairly deep water lake, with no debris or hidden rocks then SS is a good choice.|
|I've toasted 3 nibral props, one some rocks, one on some plywood, one on a stump and just dinged the new one end of last season. |
i'm going ss for my next purchase the nibral never come back repaired right and i end up buying new anyway.
|By M (big_un) on Sunday, February 22, 2004 - 7:20 pm:
|If you run a ss prop, you need to use a brass/nibral woodruff key. Theory being, if you hit something,the key will sheer off before damaging your gear.|
Never heard that one before but it seems to make sense. If this is true, I would go back to my SS prop.
|if your brand of insurance covers underwater objects, pay the deductable and GO BIG. |
check out halepropeller. they make machines that other prop companies use.
|I trashed two nibral props before I switched to SS two years ago. I'll never go back. The small rocks that I hit once in a while get picked up and thrown, with no damage to the prop. Every time I hear a bang, which isn't often, I think "this is the big $ one". Well, it hasn't happened yet. Joe|
|thanks for the advice....I may wind up trying a stainless prop. gotta be cheaper than going through 4 brass ones per season!|
|Any suggestions on places to buy a prop? |
Would they also have brass woodruff key?
|I looked around when I bought an Acme, and a lot of people recommended www.propellersonline.com. They had good advice, the best price, and their service was great. |
You can ask them about using a brass or NiBrAl woodruff key with a SS prop.
|if the stainless prop spins on the prop shaft. it will prob gauld and possibaly ruin your prop shaft. so, imo the nibral key isnt a good idea.|
|If you want an Acme, PM me and I will hook you up. |
|I checked into it a bit. According to Gekko, MC, and CC. No one recalls a key ever spinning on the shaft. All impact went to the drive train. |
There is little strenght difference between Nibral and SS. However, SS is more brittle and tends to break off. Nibral is more pliable and tends to deform. Nibral is also easier to repair.
On my Gekko GTO-22. The Acme prop versus the OJ SS:
Acme had better hole shot.
Acme and OJ were close in top end, Acme a little faster.
Acme had less vibration, especially in the turns.
Acme oost less.
OJ looked a lot cooler.
Don't get me wrong. OJ makes great props worth the price. For my money, Acme was the better value. I use a shallow lake and trailer the boat. Dings are common. It is just cheaper for this cheapskate Hollander.
|"There is little strenght difference between Nibral and SS. However, SS is more brittle and tends to break off. Nibral is more pliable and tends to deform. Nibral is also easier to repair." |
I'll agree that Nibral is easier to repair, but you couldn't be more wrong about it being almost as strong as SS.
|When you compare useage as a prop at the blade thickness used, Nibral props are as strong as SS. If you compare the raw specs metal to metal, you are correct. For example "Pound for Pound, Aluminum is stronger than steel" That statement is correct. However, the modius required makes aluminum too thick for many applications. In the prop world, the new Nibral alloys have come a long way in the past 10 years and are real contenders. Look at the blades, however, and you will find them thicker than SS to give the same strength. Under power, Nibral and SS both have similar deflection rates. When they get hit, however, the Nibral tends to deform easier while the SS tends to resist until breakage. It is a matter of brittleness and the nature of the metals involved. |
The CNC Nibral props are real contenders with SS now. That was not the case 10 years ago or even with the cast Nibral props today.
Make you own decision, but I am just too cheap to break for the SS when the risk to my drive train is greater and the performance difference is just not there anymore.
Not sure I understand you correctly. Are you saying that a nibral prop flexes similar to a ss one? I was under the impression that that was the strong suit for ss and that is where they maintained the performance advantage.
|Close. SS has higher strengh per cross section mass. Because of this, the prop manufacturers make the props thinner to gain hydrodynamic advantage - less drag. There is only so much thrust the prop can generate in water, so making a prop stronger than that thrust is unnecessary. To get higher speed through efficiency, the blades are thinned out. It also makes the props lighter, spin faster out of the hole, and cost less. |
The amount of thrust is similar between prop surface areas. It varies according to design. Nibral is still designed to hold up under the maximum amount of thrust possible for the prop.
Each prop deflects under load. The prop designers account for this and design the prop not to flex too much and return to shape while not under load. The amount of deflection is up to the designer and engineer, but it is not a huge amount of difference.
That is why although there has been a lot of progress in the last decade, it is still incremental as compared to the progress in engines from 1950-2000 with several dramatic improvements.
In racing, the prop is the least expensive way to gain extra top end. The process involves careful machining, polishing, and balancing. CNC machining takes care of a lot of this out of the box for us inboard boaters.
|Ok, Sounds like your a prop salesman. |
Once again, I had two nibral props get eaten up at the same lake in the same season.
I have one SS prop, at the same lake, going on it's third season.
I'm pretty sure the SS is stronger.
The way I see it, I'm already ahead of the game.
$125 for the average prop repair.
2 prop repairs a year for 2 years = $500
My insurance covers underwater damage.
Deductable = $250
So even if I someday kill all my under water gear, and my shaft, and the tranny, I'm covered.
By the way, having a nibral prop doesn't always protect you from all the damage I listed above. If you hit the wrong thing, your boat is going to the shop no matter what prop your running. Joe
|If anyone needs a stainless prop, we are one of the largest cutter distributors on the east coast. we have a sale going on now $269.99 ($100 dollars off)for a four blade stainless inboard or v drive prop, and free priority shipping. |
our website is still under construction, but check us out @ ABCWatersports.com
|I've been running a Stainless Cutter Prop, works great. I would have no problems buying another one.|