What SS prop for 19.5 Tyee & 225 H.O. Etec?

[tazmnaz]

I have a 1998 (Alum.) Lund Tyee 19.5' Guessing dry weight at 1700lbs + 50 gal fuel, 3 batts, gear, elect. troll motor.
Just ordered new 2008 ETec 225 H.O. 20" shaft
Wondering on SS prop. recommendation?
Had 1998 FICHT 150, but not sure what pitch alum. prop was rigged w/ as is still in winter storage but was good out of hole and great top end about 44 mph.

I am sure I will not have any holeshot issues at least based on my last engine and would like to swing to side of higher top end if the choice has to be made.

the closest test results I can find are on evinrude website with 05 Polarkraft Kodiak 1910 Pro TC and BRP Raker 22" 3 blade getting topend of 57.7MPH.

Is there diameter choices and what does that do?

 

[Silvertip]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

Diameter of a prop is based on its design characteristics so you will see slight diameter differences between manufacturer "A" and manufacturer "B". Even within the same manufacturer, diameter change. The first requirement is that the prop needs to fit the engine without hitting anything so that's were diameter limitations enter the picture. Without some wide open throttle RPM numbers with an average load we really can't help you but you can work with the selling dealer. They will generally let you try various props or perhaps can even recommend the right prop from the git go. Otherwise, unless someone comes by this forum that happens to own the same identical boat and engine combo, we can only guess. The correct prop is one that allows the engine to rev at the top of its wide open throttle rpm band with an average load. The dealer can get you close, but engine height, trim and playing with props will be necessary to optimize the setup.

 

[Silvertip]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

Diameter of a prop is based on its design characteristics so you will see slight diameter differences between manufacturer "A" and manufacturer "B". Even within the same manufacturer, diameter change. The first requirement is that the prop needs to fit the engine without hitting anything so that's were diameter limitations enter the picture. Without some wide open throttle RPM numbers with an average load we really can't help you but you can work with the selling dealer. They will generally let you try various props or perhaps can even recommend the right prop from the git go. Otherwise, unless someone comes by this forum that happens to own the same identical boat and engine combo, we can only guess. The correct prop is one that allows the engine to rev at the top of its wide open throttle rpm band with an average load. The dealer can get you close, but engine height, trim and playing with props will be necessary to optimize the setup. Just for the record, running some numbers through the prop calculator says the boat MIGHT do about 60 at 6000 RPM with a 23P prop and 14% slip. Those are theoretical numbers and do not mean the boat will actually do that.

 

[tazmnaz]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

Diameter of a prop is based on its design characteristics so you will see slight diameter differences between manufacturer "A" and manufacturer "B". Even within the same manufacturer, diameter change. The first requirement is that the prop needs to fit the engine without hitting anything so that's were diameter limitations enter the picture. Without some wide open throttle RPM numbers with an average load we really can't help you but you can work with the selling dealer. They will generally let you try various props or perhaps can even recommend the right prop from the git go. Otherwise, unless someone comes by this forum that happens to own the same identical boat and engine combo, we can only guess. The correct prop is one that allows the engine to rev at the top of its wide open throttle rpm band with an average load. The dealer can get you close, but engine height, trim and playing with props will be necessary to optimize the setup. Just for the record, running some numbers through the prop calculator says the boat MIGHT do about 60 at 6000 RPM with a 23P prop and 14% slip. Those are theoretical numbers and do not mean the boat will actually do that.

Thanks, I guess I may have to wait until I hit the water in the spring and do some trials if they let me. I know BRP recommends WOT at 4500-5800, which is a big range. Should I be shooting for hitting over 5800? I know with my current setup, I would use the trim to adjust WOT RPM to hit about 5200-5500 and seemed to peak where the recommended max RPM was just before starting to cavitate. Is this what I would be looking for to gwt max speed?

 

[Silvertip]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

The purpose of trim adjustment is not just to control engine rpm. It controls boat attitude. The best trim position is where the maximum boat speed is achieved and additional trim does not increase boat speed. The prop should be selected that allows the engine to rev at 5800. Remember, the new engines have some smarts that records if and how long an engine has exceeded red line. That means a service department may deny warranty if something happens and the engine was routinely operated above red line.

 

[tazmnaz]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

Sounds from your description that the prop on my old motor was very well matched, which is why I liked it and seemed to be outperforming lighter boats with higher horsepower. I hope I can find that same match on my new motor. I will have to check the existing pitch and maybe go from there for the new motor. With the same setup, is there much difference noticed going from an aluminum prop to an SS prop in holeshot, fuel efficiency or top end?

 

[walleyehed]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

I'll give my input because we have similar boats and HP's....
With the engine directly on the transom and no jackplate, engine in the third hole down from top..the Raker might be alright in a 20P, but I've found by much trial, and some error, that a Turbo1 works "real" good on this type application.
The Viper would be an "OK" all-around prop, but won't catch a T1 if the engine is set up at the right height.
Not sure what your other rig has on it, but I'll bet it's around 17P
If you want to get close, we need a base-line, and the prop you have may be a good test on the new engine...May be awee bit too little of pitch to. Guessing, I'd start in the 19 range maybe even a 21 in alum, then set-up for SS.

 

[Silvertip]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

There ya' go Taz -- you heard it from the Prop Master!

 

[tazmnaz]

Re: What SS prop for 19.5 Tyee & 225 H.O. Etec?

I'll give my input because we have similar boats and HP's....
With the engine directly on the transom and no jackplate, engine in the third hole down from top..the Raker might be alright in a 20P, but I've found by much trial, and some error, that a Turbo1 works "real" good on this type application.
The Viper would be an "OK" all-around prop, but won't catch a T1 if the engine is set up at the right height.
Not sure what your other rig has on it, but I'll bet it's around 17P
If you want to get close, we need a base-line, and the prop you have may be a good test on the new engine...May be awee bit too little of pitch to. Guessing, I'd start in the 19 range maybe even a 21 in alum, then set-up for SS.

Thanks for the great info! I shall work on it once the ice goes away, gonna be longing for spring now!