Prop recommendations

[speedmerchant]

Re: Prop recommendations

James, if that is your decision then I would recommend buying from either Dan's Discount or Propgods as they both have an exchange program for testing props and have a great range of props they carry. I have also heard that Iboats has an exchange program available as well, I just don't know the actual guidelines for it. Just make sure how many exchanges you are allowed and exactly what the cost is for each prop, including shipping. My recommendation would be a Michigan Apollo 14" x 21" pitch. It is a high rake, progressive pitch prop with cupping and should help with the prop slip you are experiencing right now as the cupping helps control the water coming off the prop. And you can purchase it for less than $ 250.
If that doesn't do the job then I would take Dhadley's advice on the Turbo Vector 14 1/2 x 21" pitch.
James, I wasn't worried about a performance loss with the old aluminum prop, I was worried about a gain in RPM that is not commensurate for the pitch of the prop itself and thus the increase in prop slip. When props have had something happen to the blades by hitting something you never know which way the prop will react, either it can increase the RPM or it can decrease them, I have seen it both ways.

H

Sounds good to me. I will try both Dhadley's recommendation and a 14x21 Apollo as you suggest. Will let you know the results once I get to try them. Thanks again and standby......

 

[hwsiii]

Re: Prop recommendations

James, I will be waiting to hear the results.

H

 

[speedmerchant]

Re: Prop recommendations

Ok, so finally got a propeller to try. Living in Northern Ontario, Canada I have been having problems finding a dealer that would be willing to let me try out props, mostly because up around these parts they don't stock these types. Mostly all Lund type fishing boats with outboards around here. This also limits what manufacturer of props I could get to try. Long story short I was able to first get a Volvo Penta QL stainless to try first, which I did this weekend. It is a 14 3/4 x 19.
When I went out on day 1 the test details were exactly the same as the previous test with my oem aluminum. same fuel level etc etc. With this prop I managed a two way average of 53.8 mph. RPM was 4700 (against wind) and 4800 (with tail wind). With the slight tail wind she actually pulled 54.9mph on GPS! Suprising. And the slowest run was 52.7. So I think things are right in line here. Then decided to leave it on for the next day as there would be 4 of us plus coolers and gear for a day out on the lake wanting to see how it would do with a full load. Also topped up the fuel tank as well. So with all that in mind, it came out of the hole "ok". Nothing impressive as the day before without this kind of load. Top end was running about 49-51mph at 4500-4600rpm.

So what do you guys think? To me, I think that if I were to try a 21" It might take me out of the operating rpm range even under light loads or just on the edge and would have problems with the load I had on it yesterday. So am I right in thinking that this 14 3/4 x 19 ss is pretty much perfect? Thanks for all the help.

J

 

[elkhunter338]

Re: Prop recommendations

I would agree this is the size prop you want, that way if you add weight you are ok with the boats performace. I was told a risk with a ss prop is you can bent your prop shaft if you hit a rock or log, I was told run alum. I get more top end speed with the larger pitch prop, but I suffer engine rpms.
Does really running 4,000 rpms at wot in a v-8 really hurt the motor?
I run my 3.0 chevy overproped some, but only run it at 1000-3,000 rpms, with very short runs at wot. I get better fuel economy with an overproped boat running at about 2/3 throttle 20 mph at about 2800-3,000. in-line 4 do not seem to like the high rpms. I loose top end speed when the motor turns 4400 rpms at wot, I gain top end speed when wot rpms are 3800-4 vs. 4200-4600 rpms. In line 4 turns slower than a v-8.

 

[hwsiii]

Re: Prop recommendations

Speed, it appears that you gained 4 MPH in top speed and even gained .2 of a MPH with 4 people in the boat versus only 1 person with the old prop. I do believe you will not be in the recommended RPM range with a 21" in that prop, and you are going faster with 4 people in the boat than you were with 1 person, so I believe you are in great shape with that prop and I hope you are happy with your new speed.


Prop Change

H

 

[speedmerchant]

Re: Prop recommendations

That's what I was thinking H. Thanks to everyone who chimed in here to help out. I think this is a great success and have squeezed out every last mph while keeping the boat useable. I am REALLY happy. Thanks again guys.