Outboard for a Hartley TS18

[sofala]

Hey guys,
I've recently purchased a Hartley TS18 that needs some restoration work - new deck and cabin roof, painting etc.. However, it didn't come with an outboard and I was wondering what your thoughts were on what would be the best size motor for this boat. I will be sailing her as much as I can, so the motor would be mainly for docking etc. - although a leisurely motor cruise would be nice once in a while.

Cheers, Sofala

[epoxyboy]

2hp would be adequate for docking (and they are really nice and light to handle), and more than 4hp is a complete waste. A 4hp motor on a boat that size and type will probably never get past 1/2 throttle even punching into a bit of a head wind, and in calm conditions probably 1/3 throttle will have the boat going as fast as it is ever going to go. If buying new see if there is a high thrust propeller option, take it as it is more suited to the sort of hull you are trying to push and the speed it will go.

Pete

[Woxbox]

Right, everyone oversizes motors on sailboats. The smaller and lighter, the better. Keep in mind the weight will be just where you really don't want to add weight on a sailboat.

[Larks]

Hi Sofala, congrats on the Hartley, you will love it. I have a 9.5hp Johno' long leg on my TS16 purely because it was a good one that was offered to me for nicks so I just chucked it on without thinking too much about it. I thought it might be a bit too heavy but the boat doesn't seem to notice it and the only problem I found was having to close off the top of the centreboard case to stop the spray when I get a bit of speed up. I found it opened up an unexpected alternative of going out fishing on a flat day without rigging up (leave the mast etc in the shed) so wouldn't bother going down to a smaller outboard now.

Prior to that I had borrowed a mates 6hp and although it was not a long leg and therefore lost bite in any chop it was ideal power wise. So most importantly get yourself a long leg outboard or a transome mount to drop it lower.

cheers
Greg

[JimJ]

Sofala. Congratulations on the Hartley. I have a 1983 Johnson 7.5hp longshaft on my Hartley TS18. We try to use a smaller, 2 hp if I can borrow one, when we race.

As to the restoration have a look at
http://www.woodenboat.com/forum/showthread.php?t=411&

http://sealarkrestoration.shutterfly.com/action/

Any questions, just ask.

JimJ

[kengrome]

I have a 9.5hp Johno' long leg on my TS16 purely because it was a good one that was offered to me for nicks so I just chucked it on without thinking too much about it. I thought it might be a bit too heavy but the boat doesn't seem to notice it and the only problem I found was having to close off the top of the centreboard case to stop the spray when I get a bit of speed up. I found it opened up an unexpected alternative of going out fishing on a flat day without rigging up (leave the mast etc in the shed) so wouldn't bother going down to a smaller outboard now.I've been told that the hull of this boat is the same as the Hartley Fisherman 18, of which I have plans but not yet built. The web page for the Fisherman 18 says the boat can use a 5-20 HP outboard:

http://www.hartley-boats.com/fisher18.html

It also says it will accept an inboard of up to 50 HP, but I have a feeling this is a bit of overkill.

[JimJ]

but I have a feeling this is a bit of overkill.I do not know about overkill. If you can put 125hp on the back of a 5.6m F/G fishing boat, 50hp on the back of a 5.5m Hartley should be OK.

I guess it depends how fast you want to get to your favourite fishing spot:)

http://www.hirecraftmarine.com.au/stacer_detail.asp?ID=271

[sofala]

Thanks for all the information - I think I'll go for the 7-9 hp it seems the most flexible. Also, I hadn't thought about the leg length. Cheers, Mark

[seanz]

When I got my Hartley TS18 it had a 5hp on it. Five horse that's not much thought I but it is in fact (technical term) heaps.
Of course 7 to 9hp won't be too much either......
If you're buying second hand anything at or under 10hp should be fine.

[kengrome]

I do not know about overkill. If you can put 125hp on the back of a 5.6m F/G fishing boat, 50hp on the back of a 5.5m Hartley should be OK.Hi JimJ,

When I said 50 hp inboard that means the inboard engine will be installed down in the bilge in the middle of the boat where its weight would contribute to stability and righting moment -- not hanging on the back off the transom where the weight would be a detriment to these characteristics.


I guess it depends how fast you want to get to your favourite fishing spot:)

http://www.hirecraftmarine.com.au/st...ail.asp?ID=271 (http://www.hirecraftmarine.com.au/stacer_detail.asp?ID=271)You're comparing two very different hull types. This link shows a boat that is clearly a planing hull, and the Hartley 18 is not a planing hull boat by any stretch of the imagination ...

The Hartley is clearly a displacement hull, or at best a semi-planing or semi-displacement hull type, and this means there is a practical limit to the speed any engine will make it move.

In absolute terms nearly any boat hulls can be pushed to its full calculated hull speed with only 1.0 hp for every 500 pounds of total weight. Planing hulls like the one in your link need 10 times this much power to plane, or 1 hp for every 50 pounds of total weight. Given the fact that the Hartley hull is more of a displacement hull than a planing hull, my guess is that it *might* move a little bit faster than its calculated hull speed with more than 1 hp per 500 pounds of weight ... but not very much.

If the Hartley's total weight fully loaded is 2500 pounds a 5 hp engine will push it at hull speed, and this is nearly the highest speed the hull will achieve in real life circumstances. Any additional power will suck up much more fuel, but the extra power will not increase its top speed by a significant amount. Instead the transom will squat, the bow will rise, and the boat will use all the extra power digging a bigger hole in the water and trying to push that water out of the way -- rather than climbing up out of the hole and skimming along on top of the water like a planing boat would.