Prop Shopping

[Dzrtcj7]

I need to pick up a new prop for my 1989 VIP Vindicator. The current prop is a 15x17, but is heavily damaged. My dad (a metal worker by trade) pounded it out and filed it enough to do some testing on the water, but it still vibrates enough that I don't want to push it.

With the current 15x17, 4500 rpms is about half to 2/3 throttle, doing about 40mph. Based on the ideal WOT of 4800 rpms, I figure I need more pitch. Stock spec's show using a prop up to a 23p for this boat.

Based on that, I'm looking at running a 21p Turning Point Hustler. From my limited knowledge, that seems like a logical place to start. I would love to know the experts opinion. I'm going to order a prop in the next couple of days.

Specifications:
1989 VIP Vindicator
Length - 19'
Beam - 7'9" ??
Hull style - Deep V
Dry Weight - 2500lbs
Wet Weight - approx. 3000lbs
Engine - Ford 5.0HO, 4bbl - Just built with at least performance cam and intake, thru hull exhaust.
HP - Approx. 225.
Outdrive - OMC Cobra, ratio 1.5, fresh re-manufacture.
Prop - Unk. manufacturer, aluminum, 15x17.
Use - Mostly top end, fast cruise point A to point B. Limited towing. Mostly flat water or light chop. Max 4 people on board.

Maybe someone with more knowledge about these hulls can offer some input on to why the previous owner installed a hydrofoil on the outdrive. Were they trying to correct an inherent issue with the hull design/ planing characteristics? The boat pops up on plane very easy currently. I'm planning on pulling the hydrofoils off to see how the boat is affected.

I have very limited knowledge on prop sizing. A 21p is the direction I'm headed right now. I would appreciate any education/ opinions/ knowledge that you have.

Thanks for the help.

Don

 

[Bondo]

Re: Prop Shopping

Ayuh,... I think I'd hit craigslist or ebay,+ grab a cheap aluminum wheel in 21",+ Try it....
Ditch the whaletail, Before you try it...

No sense in spending alotta money learning what the WOT is...
And,...
Ya always should have a spare onboard...

 

[180shabah]

Re: Prop Shopping

iboats has the hustlers for $105 including the hub. TP also has a prop exchange program, as long as it is still in new condition, they will exchange it for a different size - no charge.

 

[Dzrtcj7]

Re: Prop Shopping

Can anyone give me a technical basis for the difference in opinions between the TP Hustler and the Solas? The venting of the Hustler is not a factor for me because I have thru hull exhaust.

After lots of reading and crunching some numbers in a spreadsheet, I and it seems that the Hustler does not follow the "norm" as far as increase/decrease of RPM's due to changes in pitch.

Unless someone can explain characteristics that set the Hustler apart, such as handling, bow/stern lift, efficiency ... I'm going to go with a Solas in the 21p variety.

Also, I see the Solas Amita is offered in the 21p flavor with two different diameters - 14 3/10" and 14 1/4". Seems pretty marginal. Is there any performance difference to consider?

I'm all ears for any thoughts and opinions.

Thanks.

Don

 

[hwsiii]

Re: Prop Shopping

Dz, that is exactly why I do not recommend the turning point hustler, from what I have seen the numbers do not fit a pattern that I can reliably run numbers on and feel confident that I am picking the correct pitch.


H

 

[Dzrtcj7]

Re: Prop Shopping

Well, I totally went against my better judgement and made an impulse buy, lol.

Since I'm basically shooting in the dark with currently damaged prop and a modified engine, I got sold on the exchange program with the Hustler. For $20 I can send the prop back if it doesn't work out for me.

I decided to start high and ordered the Hustler 23p. There are decent odds this may be too much prop. I'll have to decide between making more HP (I have access to better heads), or exchange for a 21p prop. Either option is pretty painless.

I will be sure to post up all the data I can get until I come up with a prop that works.

 

[Dzrtcj7]

Re: Prop Shopping

I took the new 14 1/4x 23 prop out for run today. Unfortunately I didn't have a GPS on hand, but I think according to the Prop Slip Calculation, the boat speed indicator is pretty close.

So, I was able to get 4200 RPM at WOT, showed 55 mph indicated. I believe that worked out to about 10% slip.

I see that is at the bottom of my max RPM range, but I have a couple things working against me. First, I can't get my swim ladder to stay up ... makes a nice roost though, I also have some carb tuning issues to work through.

I'm going to get the ladder fixed up, work on the carb, change plugs and double check the timing and take it for another run (with a GPS) soon. It started to get a little squirrely at about 55 mph, so I don't know if that hull is going to want to take a whole lot more speed.

At this point I don't see a reason to send this prop back.

 

[trendsetter240]

Re: Prop Shopping

I took the new 14 1/4x 23 prop out for run today. Unfortunately I didn't have a GPS on hand, but I think according to the Prop Slip Calculation, the boat speed indicator is pretty close.

So, I was able to get 4200 RPM at WOT, showed 55 mph indicated. I believe that worked out to about 10% slip.

I see that is at the bottom of my max RPM range, but I have a couple things working against me. First, I can't get my swim ladder to stay up ... makes a nice roost though, I also have some carb tuning issues to work through.

I'm going to get the ladder fixed up, work on the carb, change plugs and double check the timing and take it for another run (with a GPS) soon. It started to get a little squirrely at about 55 mph, so I don't know if that hull is going to want to take a whole lot more speed.

At this point I don't see a reason to send this prop back.

Wow, you've done well on that shot in the dark! The TP Hustlers are a very aggresive prop and as mentioned difficult to predict how they will affect RPM when you change pitch.

If you are happy then stay with what you have. If you want to shoot for higher in the RPM range than trade the 23 in for a 21. I expect you will see only 100-150RPM difference but that will put you in the middle of the recommended range.

 

[Dzrtcj7]

Re: Prop Shopping

Just for a point of reference, I was finally able to get a GPS on the boat this past weekend. I'm getting 54 mph turning 4100 rpm with the 23p Turning Point Hustler.

I am planning on picking up either a 19 or 21p prop in the near future, as I believe I need to get some more RPM's out of this motor. I will post data when I get the new prop on.

 

[Dzrtcj7]

Re: Prop Shopping

So, I bought a 19p Turning Point Hustler. With this prop I'm getting max RPM of 4800 with a top speed of 54 mph. A gain of 700 rpms with no change in top speed.

**Edit: Just realized these numbers were fully loaded, gf, kids, coolers, tubes, fuel, tools .... need to take it for a run empty to get a good comparison**

The 19p obviously pulls a lot harder out of the hole and makes for a comfortable 3500 rpm cruise at about 40 mph. I think I'm going to stick with this prop, unless I make some serious HP changes with the motor.

 

[180shabah]

Re: Prop Shopping

Sounds like you are right where you need to be.

I have been nothing but happy with my hustler....