prop recommendation alum to stainless

[justfishin711]

I am looking to switch from an aluminum to a stainless steel prop for better all around performance and top speed. I am unsure of what specs of new prop should be. thanks for the help.


Iboats Boat and Motor Info


1. Year, make and model of boat 2003 palm beach 23 white cap center console
2. Length, width and base weight of boat, look for boat decal on back of boat 23 ft 2800 without engune 8'6 beam
2a.What is the maximum recommended HP for your boat 250hp
3. Number of people and gallons of gas normally on boat 3 80 gallons
4. What do you use the boat for - bay fishing, crusing in bay
5. Is it a Deep Vee and if so how many degrees of Deadrise - modified vee - (based on sea craft)
6. Year, manufacturer and model of motor 2003 yamaha ox66
7. HP and gear ratio of outdrive IMPORTANT 200hp 1.81
8. Manufacturer?s recommended Wide Open Throttle (WOT) range 4500-5500
9. Anti-ventilation Plate height above the bottom of the transom of boat if it is an outboard in inches, use a straight edge or a board under the keel and sticking out to the anti ventilation plate for a reference, and take about 4 pictures for us to see.



10. Is it a bass boat or does it have a pad bottom

11. Does it have a hydrafoil, dolefin, whale tail or trim tabs - trim tabs
12. Manufacturer, model, diameter, pitch, number of blades and whether SS or aluminum props.
michigan wheel 992004 Vortex? 3-Blade Aluminum Propeller Housing, 14-1/2 dia x 19 pitch

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. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a Tiny Tach for less than $ 50
RPM ___________ Speed (GPS)___________ No. of people ____________ Gal. Gas ________

14. Are you at sea level or a higher elevation, give us the elevation in feet _sea level_____

15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way by only using the control on the console, checked compression, looked at the plugs and checked spark, is the bottom of the boat clean and barnacle free, and have you checked the Tachometer against a mechanics tach, all of the foregoing could be the reason your prop is not attaining full RPM. yes

16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop. 1 year old prop, no, not sure looking for better performance

17. Does the prop show any damage that you can see - yes chip, banged up

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 - better performance, better high end

19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.
1. 3000 RPM 16
2. 3500 RPM 21
3. 4000 RPM 26
4. 4500 RPM 30
5. 5000 RPM 33

top rpm is 5200


thanks

 

[drewactual]

Re: prop recommendation alum to stainless

Expect near the same performance from a pitch less using s/s and same geometry of blade... The aluminum flexes about the equiv of a pitch..

I ran a michwheel vortex for a bit.. wasn't happy with its performance, and though it was rated 20p, it behaved more like a 18 or 19...

The lack of flex will cost you 200ish rpms.

Stainless offers more effective cup... Keep that in mind when youre shopping..

For your rig, I'd rec a nice progressive pitch prop (which is something that vortex lacks) with a 20p average if unvented, or 21p if vented.. you may be able to twist up a 21p invented or a 22 vented, but i would err on safeties side, and rev a little higher than lug the engine... It's better to comfortably reach that max rpm than it is to struggle, if you have to choose one..

 

[justfishin711]

Re: prop recommendation alum to stainless

Do you recommend a particular brand prop? Should I be looking to purchase a 14.5 by 20 stainless prop? Wouldn't the increase in pitch decrease my rpms? Thanks for the help.

 

[drewactual]

Re: prop recommendation alum to stainless

I think your rig would like a precision prop turbo1 in 20p, 14.25diameter.. its vented, and will spin up quick as a 19p, and has fantastic geometry and cup.. the rake will keep the bow up, and bite in sharp on plane.

 

[BrianNJ]

Re: prop recommendation alum to stainless

If you keep the boat in the water, A ss prop may increase the chance of corrosion to your engine lower unit.