Print Page | Close Window

Hydrofoil or 4 Blade Prop

Printed From: The Fishing Website
Category: General Forums
Forum Name: The Boat Shed
Forum Description: Discuss all things boating.
URL: https://www.fishing.net.nz/forum/forum_posts.asp?TID=136880
Printed Date: 21 Jun 2026 at 11:48am


Topic: Hydrofoil or 4 Blade Prop
Posted By: SpearPoint
Subject: Hydrofoil or 4 Blade Prop
Date Posted: 24 Jul 2022 at 9:54am
Hey everyone,

I’m tossing up between trying some new props or fitting a hydrofoil and was wondering what the general consensus would be to try first.

I’ve got a Haines 163c with a 90 Honda on the back and currently underway she’s a bit ass heavy. Now I am aware that my boat was never meant for an outboard this heavy so I should mention that I’ve put a full floatation pod on that follows the hull to support the weight of the motor and increase the planning length. 

I usually throw all my gear and totes in the cabin and can get it balanced pretty good when up and running but she doesn’t plane at low speed well and I get a lot of bow lift out of the hole.

I’m chasing more stern lift and lower planning speed.

My current prop is a 13inch 15p 3 blade stainless and gets me to 34knots at 6000 rpm. I’m pretty happy with how it performs but was thinking a 4 blade would get me more lift. But god dam are props are expensive right now or have they always been $1k plus? 

So I’m thinking a hydrofoil could be an option or is that just patching a problem I should solve at the prop? I also don’t want to sacrifice much top speed as I do a lot of bar crossings, so any thoughts on what would slow me down least would be helpful too.

Thanks in advance guys.




Replies:
Posted By: Schampy
Date Posted: 24 Jul 2022 at 4:41pm
Have used a hydrofoil twice over the years ... Once arse heavy, once slightly underpowered/cavitating and it worked both times.
Its where I would start. They aint that expensive and solve a lot of issues.


Posted By: OneWayTraffic
Date Posted: 27 Jul 2022 at 3:05pm
If your flotation pod is an extension from the transom with the outboard hanging off of it, then it will not improve trim over having the outboard directly on the transom. Quite the opposite. The pod moves the 90hp further back, over a longer lever arm. It might be better than a non flotation pod, but not as good as being directly bolted to the transom. 

Photos might help. 


Posted By: Pcj
Date Posted: 27 Jul 2022 at 4:12pm
Originally posted by OneWayTraffic OneWayTraffic wrote:

If your flotation pod is an extension from the transom with the outboard hanging off of it, then it will not improve trim over having the outboard directly on the transom. Quite the opposite. The pod moves the 90hp further back, over a longer lever arm. It might be better than a non flotation pod, but not as good as being directly bolted to the transom. 

Photos might help. 
moving the balance further aft,counter with weight in bow,hydro may help ,trim motor up slightly(wedges)

-------------
"Times up"


Posted By: SpearPoint
Date Posted: 27 Jul 2022 at 5:30pm
Wedges aren't a bad idea actually, would get me more negative trim I suppose.

Picture of the pod below. Totally get the COG points OneWayTraffic just trying to get it working better.





Posted By: Pcj
Date Posted: 27 Jul 2022 at 5:36pm
wedges might bring motor 90 degrees to transom then might get more till value

-------------
"Times up"


Posted By: OneWayTraffic
Date Posted: 27 Jul 2022 at 8:27pm
Looks like that pod is well integrated into the hull. Not a bolt on extra. I'd try the hydrofoil and 4 blade ideas, but first I'd just get some extra ballast and put it up front. 25L of water 3m in front of the COG would offset 150kg 0.5m back. 




Posted By: Kandrew
Date Posted: 27 Jul 2022 at 9:12pm
I wouldn’t think that motor would be to heavy for that boat. Have you checked the engine height.

Search engine height on this site, there’s plenty of posts on here on how to setup the engine properly.


Posted By: SpearPoint
Date Posted: 28 Jul 2022 at 10:22am
Yea ok, I'll try some more ballast up in the anchor locker and see how that goes. Going to buy on of those bolt less hydrofoils and give that a try first.

With regards to engine height, how would raising it get me more stern lift?

I'm on the lowest hole now so have scope to go up but the cav plate sits out of the water perfectly when under way and I'm already making max revs so I hadn't given the engine height much thought. I assumed raising it when I'm ass heavy would have just caused porpsing? Or have I got that wrong?


Posted By: kimber7wsm
Date Posted: 29 Jul 2022 at 7:02am
My gut feeling is you will end up with a 4 blade. that will be the best solution to your problems


Posted By: SpearPoint
Date Posted: 29 Jul 2022 at 11:07am
Yea I think you're right. That seems like the proper solution long term.

Anyone want to take a punt on what prop I need? I assume I go down in pitch for a 4 blade


Posted By: Kandrew
Date Posted: 29 Jul 2022 at 6:36pm
My 6.0mtr tinny was a bit ass heavy so I went to a 4 blade, gave me quite a bit more lift and stability, get up and holds the plane better.

Down side lost a bit of top end and not as much control in reverse.

We did the numbers on which prop, but I was lucky my outbourd shop had a couple of different sizes and we went for the next size up because it just cruised better and gave us a bit more bite. Well recommend


Posted By: Pcj
Date Posted: 29 Jul 2022 at 6:46pm
Originally posted by Kandrew Kandrew wrote:

My 6.0mtr tinny was a bit ass heavy so I went to a 4 blade, gave me quite a bit more lift and stability, get up and holds the plane better.

Down side lost a bit of top end and not as much control in reverse.

We did the numbers on which prop, but I was lucky my outbourd shop had a couple of different sizes and we went for the next size up because it just cruised better and gave us a bit more bite. Well recommend
not much control in reverse?? mine on the v13 took a while plane but bit in  in reverse,would I have another 4 bladder YES.

-------------
"Times up"


Posted By: Bigfishbob
Date Posted: 29 Jul 2022 at 9:19pm
THe Permatrim Hyrdofoil will get you there, the Plastic versions like the SE400 will get you there as well.

4 blade props are good for extra stern lift but you lose about 3-4knots of top end speed, and sometime you lose a bit of control for reversing. 

There are high stern lift three blade props available too. I now use a Merc Enertia Prop and it has better Stern lift than my 4 blade revolution prop I used to run. 

In your situation a permatrim is probably your best and cheapest bet. Not a bde idea to check your engine height while you're at it. Correctly setting that can also help with ride quality. 


-------------
www.waikatosportfishing.co.nz



Print Page | Close Window