Hydrofoils & 4 blades prop

[Hai Nhi]

Hello everyone.

I just saw some postings on clubsearay.com about the advantages of a 4 blades prop. Sounds pretty cool so I already have plan to get the Piranha composite ones for my future yet-to-be mine boat (hopefully a Regal 2760 or a Sundancer 280 in a month or so).

I also saw some postings regarding a hydrofoil. Does anyone here use either or both? Comments? Recommendations?

Both the 2760 & 280 have T4.3L, single prop (I assume Alpha I).

Thanks.

Nhi

 

[JoLin]

Re: Hydrofoils & 4 blades prop

Depends on what you're trying to accomplish with the new props. In boats like ours they can help a bit with better hole shot, (slightly) lower minimum planing speed and midrange (cruising speed) efficiency at the expense of top end speed. They're on my list. I'm planning on a pair of Solas Rubex 4-blade aluminum props down the road.

Don't buy anything until you have all your performance figures with the existing props as you might need to buy a different pitch. Take a gander at the 'Propellers' forum to see how people figure that out.

Forget the hydrofoils. They aren't really suitable for boats like ours. Your Regal should already have trim tabs (Bennett or Lenco) and you don't mix the two. If you don't have tabs (which I'd find strange), buy tabs.

 

[greenbush future]

Re: Hydrofoils & 4 blades prop

Many would say that if your boat has trouble getting on plane, these add-ons offer some value. Usually a well matched powerplant and boat hull will run very well with no add-on required. Ever wonder why Merc or any of the motor companies dont put these things on their new products? Usually you have other problems if you dont get the perfmance your rig should. Rotten floors, saturated foam, or a untunned motor will give you poor performance.

 

[JoLin]

Re: Hydrofoils & 4 blades prop

GF, 27-28 foot boats with twin engines and big fuel tanks are stern heavy. The right 4-blade props provide some much-needed stern lift, though there's a top speed tradeoff. Tabs are desirable at take-off and to control side to side list.

My .02

 

[smokeonthewater]

Re: Hydrofoils & 4 blades prop

ALSO forget composite props... alum or stainless are fine but not composite.

 

[dingbat]

Re: Hydrofoils & 4 blades prop

ALSO forget composite props... alum or stainless are fine but not composite.

In my book, even aluminum is suspect....lol

 

[greenbush future]

Re: Hydrofoils & 4 blades prop

GF, 27-28 foot boats with twin engines and big fuel tanks are stern heavy. The right 4-blade props provide some much-needed stern lift, though there's a top speed tradeoff. Tabs are desirable at take-off and to control side to side list.

My .02

Understand, thanks. My comment was regarding the Hydrofoil, not the prop. I didn't make my comment clear. I was thinking hydrofoils was the add on item that some use to help a boat get on plane. Typically they are used on older or under powered boats, boats with water or extra weight also come to mind.

 

[rallyart]

Re: Hydrofoils & 4 blades prop

I have a four blade prop and foil on my 18'. My recommendation for a big boat, like you are talking about, is to get hydraulic helm adjustable trim tabs rather than a foil. Four blade props have many good benefits but I would never get a composite prop unless the engine is 4 hp or less. On a boat your size my strong recommendation would be stainless steel.

 

[JoLin]

Re: Hydrofoils & 4 blades prop

Nothing wrong with aluminum props, guys.

 

[smokeonthewater]

Re: Hydrofoils & 4 blades prop

true... composites are junk tho... poor performance, poor durability, and no real cost savings.... they're great on an electric trolling motor though

 

[H20Rat]

Re: Hydrofoils & 4 blades prop

Nothing wrong with aluminum props, guys.

aluminum and composite props actually have an advantage that stainless doesn't. If you hit something solid with composite or aluminum, you bend up a prop, but your engine shaft survives. With stainless steel, you risk bending up the output shaft, which is $$$ to replace.

 

[Hai Nhi]

Re: Hydrofoils & 4 blades prop

Is there any proven facts against composite? I checked out their website and they (of course) list all the positive things about it.

Have you who said composite is not good tried it yourself and compare with SS, both in performance and in accidental cases?

Just double checking

Nhi

 

[rallyart]

Re: Hydrofoils & 4 blades prop

I have not had a composite prop but I have seen friends try them. One had interchangeable blades and he thought that would be great but the blades broke off three times and he was up to the price of a stainless prop. He also lost performance when it was working right, compared to his AL prop. The biggest problem is the thickness of the materials. The extra material creates a less efficient flow of water. That's where SS picks up a bit of performance over AL also. There have been problems with consistency of blade shape on some composites but I am not sure if that is a problem now or if it was only a problem with some brands.

When you run over a branch or bark with a stainless prop it just cuts through. On my lake a stainless prop will last for years and aluminum props need to be touched up regularly.

 

[emilsr]

Re: Hydrofoils & 4 blades prop

With stainless steel, you risk bending up the output shaft, which is $$$ to replace.

That's true if you're running a solid hub.....but unless you're running 500hp+ per side you probably aren't. If you're running a delrin hub (like Mercruiser's Flotorq) the hub will take the impact and save the propshaft.

Of course if you make a habit of running aground it isn't going to matter too much what kind of prop you're running.

 

[bruceb58]

Re: Hydrofoils & 4 blades prop

I always wonder about the benefit of 4 blade props. If they are so good, why don't boats come from the manufacturer with them?

 

[freezerman]

Re: Hydrofoils & 4 blades prop

I have a 18' Glastron that came with a 3 blade aluminum prop. I changed to a 4 blade Comprop. I am very happy with it. There is a lot of rocks and sand in my lakes so it is forgiving when you hit something. For the price I carry a spare new one. As for performance, I lost about 3 mph on the top end. Cornering while pulling tubes is a huge improvement and the holeshot is instant, also minimum plane speed dropped about 2 mph.

 

[JoLin]

Re: Hydrofoils & 4 blades prop

I always wonder about the benefit of 4 blade props. If they are so good, why don't boats come from the manufacturer with them?

I've wondered why many don't come equipped with 4-blades, too. I think freezerman's experience is pretty common. I can tell you from persoanl experience that they do help a butt-heavy boat. Maybe they don't because of the top speed penalty or because they cost a little more. I dunno.

 

[Hai Nhi]

Re: Hydrofoils & 4 blades prop

Maybe the extra cost. They always try to give just enough if possible. Anything extra would be ... extra!

Nhi

 

[smokeonthewater]

Re: Hydrofoils & 4 blades prop

I haven't personally run a composite prop BECAUSE when I was considering one I read SEVERAL side by side comparison of multiple props and the comp props ALWAYS had the worst numbers... slowest acceleration lowest top speed etc and above is the first good thing I've ever heard stated about one other than by the manufacturer.
The reviews I've read on them stated that they busted blades much easier than aluminum and after just a few blades you had reached the cost of an aluminum prop....

The above poster that liked appears to be comparing it to a metal 3 blade prop... a metal 4 blade on the same boat would IMHO likely change his mind.

 

[freezerman]

Re: Hydrofoils & 4 blades prop

I am using Comprop which is a one piece blade that costs about 80 bucks. So I buy a new one every other year or so because they do wear. A 4 blade metal blade might be better but will cost more to replace. The Piranha blades are the ones that are interchangable, I do know a couple guys that weren't happy with them. They said the blades would jam in the hub if you broke one.