Stern heavy savage osprey 488

[Ally410]

Hi all, long time since I've been in here however I've aquired a new boat and was hoping for some assistance with a small problem I'm having.

Boat is a 1991 savage osprey 488. It's an ex emergency response boat that I've been doing up. Following its first water test on the weekend I was very happy with performance with the exception of the stern heavy ride at low speed and to an extent when at rest. I raised the engine as a first change as it was too low, now sits with cav plate approx 1" above the keel. Even with full trim in it still sits stern heavy a bit at non-planing speeds.

Wondering what my options are? I suspect the main culprit is the engine pod design which puts the engine further astern but without any buoyancy underneath. Later pod designs have accommodated this issue I think.

Will an engine foil/fin help?
Moving weight further forward? Currently I use portable tanks so not hard to relocate them up under the console.
Trim tabs? Happy to spend the money on the Bennett electric models however this won't help the situation at rest.
Most invasive option is to modify the rear of the hull and put more bouyancy under the engine.

Really appreciate any thoughts anyone can throw out there. I'll post some pics to help.

Thanks

[catshark]

Hi Ally410, im not really seeing the issue here you speak off. looks to me all ok . i too have a ex SES rescue c/console same size but different make (minus the pod) and mine sits the same as yours (55 seapro mercury) on mine so unsure of motor weight, but until i work out how to post pics i cant send you some of mine to compare, Happy to send you some personally , i think i see your battery in the back corner, id start with that moving up forward. good luck

[Ally410]

Thanks for the reply catshark, yeah unfortunately none of the pics I have from the weekend show the bow up attitude the boat has when underway but not planing, it's quite pronounced. Yes the battery and 25l fuel tank are down the back, agree moving both forward will likely assist the hull performance. On the plane, she runs nicely level which is good, my concern is running offshore in conditions where planing may not be possible. Cheers

[Ally410]

Happy to send you some personally

btw would love to see some pics, I found you had to use the full website if posting from your phone, otherwise gavinwbarnesatgmaildotcom is my email. Cheers

[Chimo]

Ally410

I know it will cost money so you need to decide if this is a long term boat or not and if it is then consider adding trim tabs like Lenco or Bennett. They wont lift the stern at rest but will allow you to plane much slower with the bow down in rougher water.

I fitted trim tabs to a 5.6 ally I owned and the difference was significant. Any extra weight like people sitting on the rear bench is really going to make the issue much worse. There is only so much you can do with a lack of length. My 10 ft tinny was a case in point until it got podded. Totally different machine now with a 9.9 HP on it

In reality for a flatter ride and better weight carrying capacity you need to add more buoyancy to the stern but the other way is to just get a longer boat!

If this isn't your long term boat then live with it and save your $s for a longer one later.DSCF7950.jpgDSCF7951.jpg

Cheers
Chimo

PS Or you could add welded box pods like I did on either side of the motor on your boat . Mine will support 100 kg plus standing on each one by the way so I can easily stand on them to fish and sit on the motor if I want a seat.

[Ally410]

Thanks for the reply chimo, those pods certainly look like they'd do the trick!

a similar concept is what I was thinking for my boat, I know it would definitely help it's just the most invasive solution hence wanted to explore all other options first, starting with weight distribution I guess.

As as for the boat, it will be a long termer, suits us very well and I'm also governed by where I need to store it, just fits so anything longer is out of the question. Happy to spend the money to get it right, Bennett bolt 129 trim tabs delivered from the US are $560 aud so pretty good.

as a first pass I'm thinking I should add a foil to the engine and relocate the battery and fuel tanks further forward up under the console which has a very large footprint. I'll put some hours on it and if not happy then the trim tabs might be the way to go, or worst case start considering moding the stern.

next questions I need to answer I guess are:

1. What are the best foils around these days? Engine is a 1996 evinrude 2 stroke
2. Can I relocate the battery as simply as buying longer premade battery cables and connecting them to the existing ones with suitable insulation? I'm thinking should be ok.
3. Any concerns moving the fuel tank further forward? Is is just a matter of lengthening the connection hose a few metres? Again I can't see any issues but I might be missing something.

cheers guys

[Chimo]

Ally410

If you are considering pods I suggest you go with them and not spend money on trim tabs. While they would certainly assist when you moving they will have no benefit when you are fishing or otherwise stationary. Pods will allow you and passengers to use the back seat that otherwise will be of limited use most of the time as extra weight from people will counter any move of the battery and fuel tub.

Foils will help to lift the stern again though only when your moving and they will help you plane slower too. I have a couple of different types and find them equally good.

Where are you located? If you are handy to the Gold Coast you are welcome to check out my tinny pods.

Cheers
Chimo

ShinyProps.jpg



DSCF7961.jpgDSCF7952.jpgpodsplus.jpg

PS Last pic is a commercial hull with pod equivalents "built in"

[Ally410]

Thanks for the offer mate, unfortunately I'm in Sydney.

agree with you re the pods v trim tabs, think I'll put a foil on, move some weight forward and then look at pods if need be. Here's a pic I found from the weekend with a bit of weight at the back, prob only want another 100mm at rest I reckon

[Ally410]

Here's the photo

[Chimo]

Good luck with it. Take pics.
C
C

[always trying]

Hi I had a Boat Collar ( sides only) fitted to my 4.9m Clarke about 3 months ago and it has completely improved the performance of my boat. They do transom only kits I think might be worth looking at? I stumbled across it while searching for flotation options for the Clark. Have a look they are in Nambour qld but deliver for you to fit.
Cheers

[spud477]

It looks pretty good at rest if it feels a bit bum heavy try transome wedges
and a foil they are the cheapest options

[Ally410]

Thanks guys ill check both of those options out!

[Ally410]

Hi, I thought I'd close this one out in the interests of anyone else who may have a similar problem.

As per the advice above, relocating the battery and one of the fuel tanks, in addition to fitting a stingray foil has cured they stern heavy nature of the boat as I originally described. The difference is quite amazing, boat will come on the plane as low as 3000rpm now with no noticeable bow rise. I've also finished restoring the engine and boat to as near as factory condition where it needed it, including repaint and 2 pac clear of the engine and cowl, grit blast hull and sand to 240 grit, new floor, new electrics/panels/lights etc., repaint interior etc, very happy with the result, ready for summer!

I've attached some photo's for anyone interested.

Thanks for the help provided in response to the original post, greatly appreciated.
IMG_6990.jpgIMG_7014.jpgIMG_6986.jpgIMG_7074.jpgIMG_7075.jpgIMG_7076.jpgIMG_7078.jpgIMG_7081.jpg

[Ally410]

Actually just noticed the comparison between the original photo at rest (before any weight distribution works were undertaken) and the photo taken on Sunday night, attitude in the water is quite apparent (to me anyway), about 3" higher at the stern, much more level now.
IMG_6764.jpgIMG_7081.jpg