52' Wharram

[aldiver]

I have just bought a 52' Wharram. She currently has a 68hp Saildrive in her (pod in between hulls). I want to take out the engine and replace it with two outboards......thinking yamaha 40hp 2 strokes...now am in two minds, firstly is this enough horse power? How does the single engine to double engine (outboard to inboard) etc etc compare? now I am also in two minds as to put them one on each side with a good spread for steerage (but noisy and take the weight aft) or put them together in the pod where the inboard was? All advice/input is much appreciated.

[Troutbridge]

I considered a 52' Wharram, but alas concluded I was too old/awkward so have gone for a more conventional cat. It depends on how you envisage using the boat, but I wanted a sailing boat with auxilliary power, not a motor sailor. How about two small diesel inboards? Fuel is safer to carry, less noise possibly more reliable than outboards. maybe 2 x 10hp Yanmars, something like that? Whatever, enjoy. Incidentally, was that the boat for sale in Thailand?

[sneuman]

Originally Posted by aldiver

I have just bought a 52' Wharram. She currently has a 68hp Saildrive in her (pod in between hulls). I want to take out the engine and replace it with two outboards......thinking yamaha 40hp 2 strokes...now am in two minds, firstly is this enough horse power? How does the single engine to double engine (outboard to inboard) etc etc compare? now I am also in two minds as to put them one on each side with a good spread for steerage (but noisy and take the weight aft) or put them together in the pod where the inboard was? All advice/input is much appreciated.

Beautiful boats, very seaworthy and good sailors. I was aboard one in Thailand a few years ago, though it may have been a bit smaller.

[JusDreaming]

one advantage of a catamaran is have the wide spread of the engines. It makes all the difference in the world in tight spaces. Basically you can spin them on a dime

[aldiver]

Troutbridge,
yep she was the one for sale in thailand....she would be seriously underpowered with 2 10hp yanmars, also here in Thailand i'd be looking at a lot of money to buy 2 inboard diesels.........the only options really are keep the current engine, buy an auxillary.......or buy two outboards. Problem with this engine is she only gives me 5kts.....(i think she's underpropped but changing this might give me another knot maybe...not sure, not really an expert at this stuff)

JusDreamin
Yep, I like having a spread with the engines too,

[Tnflakbait]

If I were you I would build two lowering pods for a couple of 40 or 50 hp engines. This should be enough power. Don't put the outboards too far aft as they will be more prone to coming out of the water in a pitching sea. 40 hps should be more than enough.

[roblanford]

Congratulations , nice boat.
If the engine is in good condition, I think I would be tempted to keep the diesel and make sure you are getting all you can out of it. make sure the prop is correct and there might be some modifications available to get more power out of your present engine. If you are not satisified at that point, can you upgrade to a larger diesel engine that will fit your saildrive?

If you prefer the outboard route the outboard dealer should be able to direct you to the right engine and prop combo. The available length of the lower units would make a difference in choice too.

Would you be saving weight by changing to outboards? I talked to John Marples trying to decide if I should go 30 or 40 hp on my tri telling him that the 40 hp diesel would weigh 100 pounds more. He pointed out that the additional fuel consumption would require more fuel storage and that was the number he felt was more compelling.

Lots to think about, good luck

[Fishman]

Hi there, I built 2 traditional wooden boats in Indonesia, the first was a 45ft motor sailor. I was on a VERY tight budget so I had a single cilinder diesel inboard (duff-duff-duff) as well as an old 40hp Yamaha outboard which fitted in a well. With both motors running she did 9knots with neither motor working too hard...why don't you keep the diesel inboard and just ad one 40hp outboard? I am sure you can rent a 40hp outboard for the day from one of the locals, just to see how it goes? If you are going to fit an outboard you may want to consider a "long shaft" - keep the prop in the clean water. Budget wise you already have the diesel inboard...why get rid of it?
Have fun
Fishman

[SkiprJohn]

Aloha Aldiver,
Roberts advice is good. There is something wrong with your prop/drive/engine if you are only able to make 5knots. I would suspect that you are not getting enough revs on your engine to make the proper power curve. If that's the case then you need to have a lower pitched prop to get that power you need.
Your Wharram is much larger than the one my club has (a 23) but fore and aft balance is quite important with ours because of the hull designs. Also, aren't your rudders hung on the stern of each amma like the 23? Going to two outboards seems like a big change with no advantage.
I like your description "am in two minds." That's why you bought a catamaran, right?
Good luck with whatever you choose.
Kind Regards,
JohnL

[Fishman]

One more thing...judging from where you bought the boat, you are going to have a lot of really uncrowded tropical island cruising with very few marinas (once out of Thailand you may not see another crowded marina for months!) so tight spot manuevring is not in my opinion a priority. Having the power to get you off a lee shore or out of a bad anchorage (at night off course) is what you need...if you are doing 5 knots now in I assume flat conditions then you may only do 2-3 knots in s*&t weahter...is your hull clean? Also make sure the prop gets clean water: it musnt be near a turbulent area...
Fishman

[allnunstoport]

Diver,

I too have a 52' Wharram (well a derivation on a Wharam, but really close). You must have bought White Seal? My boat is unusual in that it has a single 50 hp inboard diesel in the port hull driving a relatively large prop. She tracks surprisingly well with this configuration and gives me 8-9 knots at 90% WOT burning just over a gallon per hour. I will probably add a smaller outboard on a pod on the starboard side for marina handling, but the boat doesn't spend much time in marinas. Right now I just strap my dingy to the starboard hull and put crew in the dingy with a wireless radio headset for marina handling. Feel free to PM me if you want to compare notes.

[mikereed100]

Aldiver,

I admired your boat in Langkawi soon after it was launched. Beautifull boat, congratulations! If you can't get more speed out of your current configuration I am told that Kubota diesels can be had for fairly cheap in Thailand although I have not confirmed this.

Mike

[Mike Banks]

Well--I would fit two dc dynamotors and keep the diesel to drive a generator. The improvements in having diesel electric for a sailboat is quite something--and you could do it for the price of the two outboards perhaps. The boat has any amount of space and bouyancy for the gellcells and the weight of the dynamotors and dc generator.

When the boat drives up a wave the motors assist, when going down they generate--and this keeps the sails drawing more efficiently. Enough to replace the power lost and then some. On a cat of that size one could use a little extra power--especially in the tropics.

[geoleo]

Originally Posted by allnunstoport

Diver,

I too have a 52' Wharram (well a derivation on a Wharam, but really close). You must have bought White Seal? My boat is unusual in that it has a single 50 hp inboard diesel in the port hull driving a relatively large prop. She tracks surprisingly well with this configuration and gives me 8-9 knots at 90% WOT burning just over a gallon per hour. I will probably add a smaller outboard on a pod on the starboard side for marina handling, but the boat doesn't spend much time in marinas. Right now I just strap my dingy to the starboard hull and put crew in the dingy with a wireless radio headset for marina handling. Feel free to PM me if you want to compare notes.

That most Cats with 2 diesels usually use only one for distance cruising! SAves money and noise and great motor sailing!

[Doodles]

That's a four year old thread you know.