Prop Data Sheet

I am heading out this weekend to do the Hwsiii boat prop test and I made a pretty sweet little Excell spread sheet to write all my data on. I was wondering if anyone else might like a copy? I have tried to post it up but it just dosent look as good as the one I made. The original has room for data from four different props.

Prop 1
RPM Speed
3000
3500
4000
4500
5000
5500
6000
6500
WOT RPM Speed

Prop Make/Model

Pitch/DIA.

Re: Prop Data Sheet

I will be waiting.


H

Re: Prop Data Sheet

1.Year, make and model of boat 1992 Bayliner Classic 1950
2. Length, width and base weight of boat, look for boat decal on back of boat 18?8?, 7'9" 1995 lbs
2a.What is the maximum recommended HP for your boat 115
3. Number of people and gallons of gas normally on boat. 4, 30
4. What do you use the boat for Water toys, cruising
5. Is it a Deep Vee and if so how many degrees of deadrise Yes, 20
6. Year, make. manufacturer and model of motor 1992, mercruiser, 3.0L
7. HP and gear ratio of motor IMPORTANT 115? ,1.98
8. Manufacturer?s recommended Wide Open Throttle (WOT) range 4200-4800?? I have found several specs all a little bit different.
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene not an OB
10. Is it a bass boat or does it have a pad bottom not a bass boat
11. Does it have a hydrafoil, dolefin or trim tabs No
12. Make, model, diameter, pitch and whether SS or aluminum prop 14.25 21?
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.
14. Are you at sea level or a higher elevation, give us the elevation in feet 917
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 foregoing could be the reason your prop is not attaining full RPM All new in the spring
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop The 19 came with the boat, I bought the 21 as a spare both have been repaired, but both work for what I use them for.
17. Does the prop show any damage that you can see No I fixed them twice.
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 I am looking for a good all around prop possibly a 4 blade for wake boarding. Currently when it?s just me and the wife I put on the 21 and cruise. When I have the kids I put on the 19 to pull the toys. The lake I go to is 6 miles long so some good top speed is a must, but I?m 6? 265# and pulling me up on a wake board is problematic. If one prop cannot do everything I want, recommend 2 that would.
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. I had intended on doing a full chart but the chop was so bad, I just did the prop that was on the boat.

PROP RPM SPREAD SHEET
Prop 1
RPM Speed
3000 11
3500 24.2
4000 30.5
4500 36.5
WOT RPM Speed
4700 38.3
Prop Make/Model
?/48 8 283A45
Pitch/DIA.
21/ 14.25
Elevation 917'
Passengers 2
Fuel 15

Re: Prop Data Sheet

Jeepin, your prop slip is about 19% right now and I show if we change to a 19" pitch Solas Amita or Rubex 4 blade prop we ought to be able to keep the same speed you are getting right now with the 21" prop but your hole shot and acceleration through all of the RPM range of the motor to WOT will be muchhhh better beause of the need for pulling toys. We would actually be better off with a 20" pitch, but Solas doesn't make one and a good SS 4 blade in 20" pitch will run over $ 300 and we wouldn't have as good a hole shot and you did a great job on the testing and we didn't need the numbers for the 19" anyway.

Prop Slip




H

Re: Prop Data Sheet

Thank you sir,
Being a poor white boy with 5 kids I don?t see a SS prop coming anytime soon. I plan on testing all of my props and a 4 blade 18" MI wheel my cousin has before I buy a new one. Plus being a technical writer by trade these days I just love data, and since the water was so choppy during the test I want to make sure it didn't skew my results. Is the prop slip formula you are using available somewhere so I don't have to bother you with data from 5 different props?

Re: Prop Data Sheet

To get real data you need to run the tests in 180 degree directions to null any currents or winds. Then add the two speeds together and divide by two.

Here is an online prop slip calculator you can use.
http://go-fast.com/Prop_Slip_Calculator.htm


I would like to see the numbers you come up with after doing these tests if you don't mind.


H

Re: Prop Data Sheet

I might do that for the 21" and the 4 blade 18".
You can count on seeing my results.
I plan on perform the same test on the same props with my cousins 20' Starcraft deck boat 220HP 4.3L. Would you like that data also?

Re: Prop Data Sheet

Yes I would, thank you very much.


H

Re: Prop Data Sheet

I have been a very busy boy this year but I went on vacation last week and got some more data. Do you have a different recommendation based off of this information? Or are you sticking with the old ones?

Re: Prop Data Sheet

I see after posting this up that hwsiii has been even busier then me this summer. My offer still stands if any of you guys would like a copy of this spread sheet pm me an E-mail address and let me know if you have Excel 2003 or 2007 and I will send you a copy.

Re: Prop Data Sheet

OK I?m ready to take the plunge and get a new prop, but with the very poor performance numbers I got with the four blade prop in my data sheet I?m not sure where to go from here. My son is getting into wake boarding and he is a big boy 6? 225 #, at 14 I think he will only be getting bigger. I was hoping one of you guy's with a 3.0L and some experience with a 4 blade could help me out. What would you recommend and why.

Re: Prop Data Sheet

JeepinGunGuy said:

OK I?m ready to take the plunge and get a new prop, but with the very poor performance numbers I got with the four blade prop in my data sheet I?m not sure where to go from here. My son is getting into wake boarding and he is a big boy 6? 225 #, at 14 I think he will only be getting bigger. I was hoping one of you guy's with a 3.0L and some experience with a 4 blade could help me out. What would you recommend and why.

Click to expand...

Why do you think you had bad performance with the 4 blade? They are known to drop your top speed. If you are looking to pull big boys out of the water, AND top speed...you are chasing diverging targets...you get one or the other, not both.

I would drop 2" pitch from the 4 blade you tried, and try that. I think that would give you some sweet hole-shot and get your max RPM's up where they should be.

Re: Prop Data Sheet

Lots or reading there:

1. 18?8?, 7'9" 1995 lbs...."Big boat for a 3.0"

2. HP and gear ratio of motor IMPORTANT 115? ,1.98 ..."std gear ratio for a 3.0"

3. Make, model, diameter, pitch and whether SS or aluminum prop 14.25 21?..".large prop for a 3.0 and a big boat"

4. I am looking for a good all around prop possibly a 4 blade for wake boarding. Currently when it?s just me and the wife I put on the 21 and cruise. When I have the kids I put on the 19 to pull the toys. The lake I go to is 6 miles long so some good top speed is a must, but I?m 6? 265# and pulling me up on a wake board is problematic. If one prop cannot do everything I want, recommend 2 that would... "Sounds fun"

You have a large boat for a 3.0 and you use with a full compliment of passengers...along with waking boarding very taxing on such a small boat