Aluminum to stainless (would this be ok)

[OnTheWaterNow]

hello my question is i have a 14 foot trihaul 1994 mariner 50hphas a quicksilver 10-1/8x15prop now a little banged up want to put a appolo ss 10-1/8x 15 will there be any negative affects from this? wot rpms are 5400 not sure of speed was told my reading from x85 is probably not true and speedo reads about the same. Thanks in advance.

ps would there be any positive affects I would be able to tell?

 

[rolmops]

Re: Aluminum to stainless

Re: Aluminum to stainless

Some people will disagree with me,but I think that a stainless prop on a 14 foot tri-hull is an absolute waste of money.Apart from having a nice shiny prop,there just is not enough of a difference.

 

[OnTheWaterNow]

Re: Aluminum to stainless

Re: Aluminum to stainless

ok thanks my only thing is there realy isnt muchof a difference in price from the apolo and the quicksilver so wanted to try but just dont want to mess anything up motor runs great and is in rpm range now prop is a little rough on the blades now but now to bad just wanted to change it and keep old one for spare. thanks

 

[78ImperialT]

Re: Aluminum to stainless (would this be ok)

at 50hp the aluminum is far better...much lighter prop to turn. the stainless prop is much heavier and is usually used with higher horsepower motors because stainless will not flex under pressure like aluminum. 50hp wont flex aluminum in the least.

try hustler brand...can get the prop for around 50$ and a hub kit for around 30$.

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

thanks for reply ok dont want to spend money on a prop that will give less performance or mess anything up. I was reading about the apollo says that it is lighter than aluminun, because the blades are thiner. they saythey can make them thiner because the stainless is stronger than aluminum. so you say the ss will be heavier?it also says exhaust holes are bigger and give better preformance. I was just wondering if it would make a differance for me or not or if they are more for larger more hp motors.thanks for all help let me know what you think about them saying that ss would be lighter than alum.

 

[hwsiii]

Re: Aluminum to stainless (would this be ok)

Now, I have an Apollo on my flats boat with a 40 HP right now, they are lying about the weight big time, but the weight doesn't matter. You said you have a quicksilver right now, but you don't say which model you have. Tell us which one.
The Apollo is a higher rake prop with cup on the trailing edge, it raises the bow and the stern to some degree because of this rake and cup, and in some hulls this is a good thing. My flats boat it works well on, as I use it to raise the bow when I am in rough seas, but I also have Smart Tabs on the boat because on my hull it tends to porpoise at maximum RPM because I have the motor raised very high above the keel.
Aluminum props running less than about 45 MPH do not flex enough to change the speed by 1 MPH, no matter the horsepower, that is why they are much thicker than SS props. The evidence is in the amount of prop slip that happens at higher RPM with an aluminum prop, as the speed goes up the prop slip comes down and if the prop was flexing then the prop slip should go up. That theory is like the one that says for every 1" of pitch there is a change of 200 RPM, that only works on props with about a 20" pitch, the difference between the RPM of a 12" pitch prop and an 11" pitch prop is 400 RPM and the smaller the pitch the more the difference and the higher the pith the less change there is . The reason that stainless props offer better performance is because of the money spent to design much better blade geometry and since it is stronger it can be made much thinner.
If you can give me some GPS numbers I can tell you how much prop slip you have and how well your prop is doing its job on your boat. All you need is a hand held GPS or even some phones have it.
Now, what are you expecting the Apollo to do for you that the Quicksilver doesn't do.


H

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

Thanks,Hwsiii ok the quicksilver is a 10-1/8 x15 aluminum Black Diamond-with flo-torq I hub,not sure what to expect or notice different.the boat runs realy well no complaints.the prop now has a little damage. I want to replace and just be running a new damage free prop,so i just want to put the best prop on it that i can at this time.the motor is a 1994 mariner 3 cylinder 50 hp the book that came with it said wot should be 5300-5800 rpm Im right at 5600 now.i used my brothers phone with gps by myself it read 35 mph@5600, I wasnt sure if this was correct because my X85 with paddlewheel was way differnt. everyone says those paddle wheels are not true gps is way to go,and you say same.ok guess that is all I know or can think to share.

here is a pic if it will help at all. Oh yeah it does have a stingray on it too thanks alot look forward to hear from you http://stumpmj.spaces.live.com

 

[steelespike]

Re: Aluminum to stainless (would this be ok)

Check out the Turning point Hustler.ss performance at al. prices.
Usually do well going same pitch to same pitch. You may be able to have your prop repaired.

 

[wellsc1]

Re: Aluminum to stainless (would this be ok)

Another consideration in getting a ss prop is ruggednes. I put a ss prop on 16-foot tri-hul with a 40 hp Merc (1980 model). Why? I kept break al prop on stump-riddened lake. Now the prop is still used on my 40 Force mounted on 14-foot al flatbottom with absolutely outstanding performance. It wasn't an expensive prop, but ss nevertheless.

Keep in mind what doesn't damage the prop now transfers the impact more to the lower unit. At least now when I bump a stump, stick, or other object the prop keeps on ticking. NOtice I said "bump", not hit.

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

thanks guys i am going to keep old as spare realy isnt to bad not bad enough to send off yet

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

also was wondering about the diamater but guess you will tell me that after you run some numbers thanks

 

[hwsiii]

Re: Aluminum to stainless (would this be ok)

Mike, you are showing a prop slip of 28% right now,if it has a 1.64:1 gear ratio as I found, and that is veryyy high for a bass boat. I would like you to give me some information so I can run it through my program and see what it ought to be doing with the right propeller.
Iboats Boat and Motor Info
1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make and model of motor
7. HP and gear ratio of motor IMPORTANT
7A If you have a mercruiser and don?t know the ratio get your serial off the outdrive and go here http://www.sterndrives.com/mercruisersterndrives.html
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch and whether SS or aluminum prop
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. If you do not have a tach you can buy a Tiny Tach for $ 50
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way, checked compression, and looked at the plugs and checked spark, all of the forgoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations

REMEMBER, The numbers I give you will be NO better than the information you give me

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.

H

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

ok i will work on that now will give you all info i can come up with thanks alot be back as soon as possible

 

[hwsiii]

Re: Aluminum to stainless (would this be ok)

That will be great Mike.


H

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

Ok this is what I came up with:

1) 1981 Astroglass 140
2) 14 feet 0 inch long 64 inch wide not sure what base height means but bottom of boat to top of cap is 28 inches.
2a) recomends don not exceed 60 hp
3) 1 person (me 180lbs 6 gallon fuel)
4) fishing some cruising around
5) trihaul
6) 1994 mariner 3 cylinder 50 hp 2 stroke (not big foot)
7) 50 hp gear ratio 1.64:1 (got this from internet not in book hope it is true)
8) Wot 5300-5800 rpm manufacture recomendations
9) not sure of this if it is the plate where hydrafoil is mounted it is level with the keel
10) bass boat (trihaul)
11) hydrafoil (yes stingray)
12) prop is quicksilver black diamond 10-1/8 D 15 p aluminum
13)Wot 5600rpm@35 mph (GPS) 1 person 180 lb 6 gallon fuel
14) not sure of this im in dayton Ohio
15) new plugs carb rebuilt off of motor and cleaned compression good all 3 cyl im getting the rpms
16) prop is two years old not saying is wrong prop just has a little damage want to be running a good clean prop with no defects keep old as spare its not even bad enough to send out yet
17) little damage small chips at the tip of two of the three blades
18) not having any problems that i can tell just want a prop that is 100% clean and while im at it want the best prop for the boat and if i can increase performace while im at it that wold be great to.


Thanks alot cant wait to see what you have to say there is a link further up in the post with pics if they will help any thanks see ya soon. mike

 

[hwsiii]

Re: Aluminum to stainless (would this be ok)

Mike, I ran some numbers on your boat and I question the gear ratio, as I am showing a 28% prop slip with that gear ratio. I hope it is true, because if it is we can certainly gain you some speed. But before we go buying a prop that could be wrong, it would be good if you would go to the Mariner/Mercury forum on this same forum site and find out if that is the correct gear ratio, we don't want to waste your money with the wrong prop.
I find the pitch should be exactly what you are using, and the Black Diamond prop is just a knockoff of the Black Max by mercury, and I happen to have one of those for a spare on my boat. I will be going out early next week and I will take the apollo off and put the Black Max on and see what kind of difference it makes. But my Apollo is a 14" pitch and the Black Max is a 12" pitch, so there will be a real difference in RPM, RPM but I will see what differences there are in handling characteristics between the two. My boat is a flats boat kind of like your bass boat, but with no pad on the bottom. I will let you know as soon as I do it.


Prop Slip

H

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

k im seeing some different ratios i dont know where to find it i googled what is my gear ratio for my motor and im finding alot of different answers for my motor

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

ok Hwsiii i posted over there ill let you know what they say thanks

 

[OnTheWaterNow]

Re: Aluminum to stainless (would this be ok)

saying my gear ratio is 1.83.1

 

[hwsiii]

Re: Aluminum to stainless (would this be ok)

Mike, this is my recommendation for an inexpensive prop that will bring down your prop slip and you should show an increase in speed as well as keep you RPM at the top of WOT recommendations.


Price: $94.98
Add QL Aluminum Propeller Prop: 41102310 Hub: 41102350 To Your Cart

Propeller Specifications:
SKUrop #41102310Hub #41102350
Manufacturer: Volvo Penta
Brand: QL
Material: Aluminum
Diameter: 10 - 1/2?
Pitch: 14?
Blades: 4
Rotation: Standard (Clockwise)


H