SS vs. aluminum

[greenwell001]

after replacing the throttle control......and cables.....paying for storage fees all winter... and i need to change prop pitch and dont want to spend 400 dollars on a new ss prop.....i have a 21 ft 5.7 l alpha one......i run on the ohio river, so the question is what exacty would i gain or lose with going with an higher end aluminum prop, thanks

 

[dave11]

Re: SS vs. aluminum

I' just get a second aluminum prop with a little different pitch. SS may give you a bit more speed and better effiency. The aluminum props are cheaper and it costs less to repair them.

 

[Swishguy]

Re: SS vs. aluminum

Go up about 2 sizes in pitch & same diameter to get similar performance.

 

[redone4x4]

Re: SS vs. aluminum

the aluminum ones are a little giving, meaning that i would rather repair an aluminum prop from striking a rock vs. the stainless one sending the shock thru the outdrive and such. theres good points to the ss ones, but like you i cant justify the price jump.

 

[greenwell001]

Re: SS vs. aluminum

Go up about 2 sizes in pitch & same diameter to get similar performance.

i have a 23 pitch, not exactly sure the diameter aluminum prop....as for the pitch change i wanted to go with a 21p......but your saying my 23p aluminum is acting like a 21p ss prop.....maybe my engine is not a powerful as i thought it was

 

[hwsiii]

Re: SS vs. aluminum

Green, if you will give me your WOT speed and RPM and the gear ratio of your lower unit I an help you.



H

 

[greenwell001]

Re: SS vs. aluminum

hwsii,

wot @ about 4500 rpm and around 50mph. the drive is alpha (gen 1 i beleive)but not sure of the gear ratio, how can i find out

 

[hwsiii]

Re: SS vs. aluminum

Some of the time it is written on the lower unit.

7. HP and gear ratio of outdrive IMPORTANT
If you don?t know the gear ratio, you need to pull the plugs out of the motor and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor


And if you will give me the year and HP of the motor I will see what I can find. And if you will give me an exact WOT RPM and speed I can recommend a better prop for your boat.



H

 

[greenwell001]

Re: SS vs. aluminum

thanks for the help h,

the motor is the 210hp non vortec two barrel 5.7 and i will post a pic of the outdrive for u, because i dont know the difference between gen 1 and gen 2 alphas....i got the boat last year.. it has thru hull exhaust coming out on the sides of the boat...keep in mind that this is my first boat and i am pretty ignorant about these issues. wot @ 4500rpm and 50 mph. the motor is a 96

 

[hwsiii]

Re: SS vs. aluminum

Sorry, I need the pitch of the prop as well.
I found it.

I show your motor as having a manufacturers recommended WOT RPM as ranging from 4,200 to 4,600 RPM and a gear ratio of 1.47:1, BUT I need you to verify the gear ratio, as I show your prop slip at 25% and that is exceedingly high.

If the gear ratio is right I have a great prop to recommend that will only cost you about $ 120.


H

 

[greenwell001]

Re: SS vs. aluminum

i will check it out as soon as possible and confirm your research. thankyou for your help......give me till tomorrow as i have to take my little girl to the doctor in a min....

 

[hwsiii]

Re: SS vs. aluminum

Green, I hope she is fine and has no bad problems.



H

 

[greenwell001]

Re: SS vs. aluminum

h,

the ratio is 1.47:1

 

[hwsiii]

Re: SS vs. aluminum

Green, you need to purchase a Solas Aluminum 21" pitch 4 blade prop for your boat. You RPM will rise up to maximum and your hole shot and acceleration will increase dramatically as well as you will be able to plane at lower speeds and hold plane at lower speeds as well. And you should gain a couple of MPH.



H

 

[greenwell001]

Re: SS vs. aluminum

you the man h, thanks for the help buddy