Message for Walleyehed

[cloumar]

Hi Walleyehed,

Since you have a lot of experience with props here is a question for you:

My boat - Smokercraft ProMag 162 - 16.5 feet
Engine: Force 1998 - 75-HP ( small gearcase )
at WOT I am running at the max. spec 5250-RPM and around 26 to 29 MPH with a Hustler alum. prop ( 101/2'' by 13 pitch) from Turning Point Co. - Also the AV plate is in line with the bottom of the boat, right on not above and not under.
The question is if I want to go with a stainless prop. what pitch and or diameter I should go and any brand to suggest.

Thanks

Mario

 

[cloumar]

Re: Message for Walleyehed

one up

 

[walleyehed]

Re: Message for Walleyehed

Take a look here.......
http://www.iboats.com/mall/propfind...id=160&session_id=618659028&cart_id=733937387

Knowing how hard a Hustler pulls, this may be the best option and allow some engine heigth if needed...
http://www.iboats.com/mall/propfind...id=160&session_id=618659028&cart_id=733937387

 

[cloumar]

Re: Message for Walleyehed

Thanks for your answer Kenny ,

When you say that the Hustler pulls hard, you mean that it is a good prop for aluminium ?

Is this the reason why I could remain with the same pitch or increase only by one inch for a stainless, is it because it doesn't flex as much as a regular alum prop.?

Mario

 

[walleyehed]

Re: Message for Walleyehed

Yes, the Hustlers I've tested have shown to pull a bit lower RPM than most aluminum props.
TexasMark, on the fora here, says he found the same basic results.
As for SS props, most do not flex as much as alum, but the biggest factor is the thinner blades and how those props are cupped. They tend to have slightly more lift in the same blade designs and over-all, are more efficient.
The holding ability of the SS is normally greater and allows a higher engine mounting position, leading to less gearcase drag and more speed/RPM which means better fuel economy.

 

[cloumar]

Re: Message for Walleyehed

Thanks again Kenny,

I will probably go with the Appolo 14'' pitch. But this will be only next season, because winter is almost here :'(

Mario

 

[walleyehed]

Re: Message for Walleyehed

Call iboats, ask for Brad, Tell him Kenny told you to call, and give him that P/N and ask him if there are any price increases for spring......you "may" want to tag one now as they are "usually" cheaper in the fall.

 

[cloumar]

Re: Message for Walleyehed + one more question

Re: Message for Walleyehed + one more question

Kenny,

You suggested me 2 different pitch in two different model - can I go 14'' pitch the rapture the same for the Apollo can I go 13'' pitch.

Thanks

Mario

 

[Texasmark]

Re: Message for Walleyehed

Thanks Ken,

Jumping in here. If you missed it Cloumar, I was running a high perf SS prop and due to clutch dog rattle, I decided to get a lightweight (hence alum) prop. I chose Hustler because it seemed to have a lot of high performance design in it for alum; not plain jane like most.

I was running a 24P SS but the highest pitched Hustler available was 23P. My engine was running 100 rpm over the max WOT rating so if the inch gave me another couple hundred rpm's I shouldn't be hurting anything I thought.

In reality, even though the pitch was 1" less and should have given me an extra 200, I lost 600 rpm's and about 3 mph of speed. So that is an effective rpm loss of 800 rpm.

I had the props on the table side by side and only two things came to mind as to the reason. The blade area of the Hustler was larger than the other meaning it "ran harder" as Ken said......more blade to push against more water hence needed more hp to turn at a given rpm.

Next, the alum blades were much thicker than the
SS. How much force does it take to swing a baseball bat thru the water vs a machette? Get the point? The fatter alum blade required more hp to push it thru the water at a given rpm.

So, as Ken said it ran harder, not better, loaded my engine and as a result I lost rpm's and top speed.

Hope that helps.

(Needless to say the alum is back in the box and sitting on the shelf. d )

Mark

 

[walleyehed]

Re: Message for Walleyehed

Mario, the pitches on the particular props I listed was based on test data I have on how 1 brand pulls over the other. If you have an RPM issue, we can adjust engine heigth to get a few R's back...but the 14 Apollo is going tp pull about the same RPM as your 13 hustler, but speed will be higher.

 

[cloumar]

Re: Message for Walleyehed

Guys thank you a lot, you gave more inputs again !


Mario d