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georgeblackwood
31 Posts |
 Posted - 03 Jun 2011 : 20:06:10
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Hi all,
I've recently purchased a Norman 17 for canal/river/lake cruising without an engine.
I've read through a lot of the previous posts on this site about engine size and shaft length and it appears that a long shaft engine is what I need to be looking out for, however I've come across this website while searching on Google and it seems to be advising short shaft. From the top of the transom to the bottom of the keel is a little over 16 inches.
http://www.onlineoutboards.com/Help.html?Question=Shaft-Length
Does anybody on this forum use a short shaft on their Norman 17? There are a lot of weeds in the canals around where I live and I'm guessing that a short shaft might have the advantage of the prop not getting tangled up in them as much.(This might be wishful thinking on my part!)
Thanks for your help. |
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cliveshep
Thailand
1324 Posts |
Posted - 03 Jun 2011 : 21:37:32
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If you have 16 inches from transom top to bottom of transom/hull then you need a short shaft motor which is designed for up to 17 inches.
The anti-cavitation plate on the motor leg should be just below the bottom of the hull in a clear "swim" of water. You are going to ask me what the anti-cavitation plate is so I'll forestall that - it is the horizontal oval plate all around the lower unit right above the propeller and stops the prop sucking down air from the surface, (cavitating), and also keeps the wash deeper for longer as it directs it out straight. Most of the wash is caused by propeller inefficiencies as if it was a screw in something more solid it would screw itself along. As it is it slips a certain amount but the resultant stream of water also returns some of the lost screw effect as it jets the water backwards giving resultant thrust forwards. Some effort of course is lost as water slides off the blade tips sideways but the general effect is like hitting your flat hand on water hard - the water becomes apparently more "solid".
As for weeds - you're right about wishful thinking but if it is any comfort the fast spinning prop of an outboard chops most up pretty good and if you run into that long tough grassy weed that winds up around the prop you can sometimes clear it by going hard astern for a moment. Failing that it's tilt up and a sharp knife I'm afraid.
For canal/river/lake you'll want anything from 8hp up to 15hp on a Norman/Callumcraft 17. *hp will be perfect for canals and lakes, if your cruising ground has currents of any strength then 12-15hp.
The cost of boating is insignificant compared to costs of a young wife and two teenage kids! |
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georgeblackwood
31 Posts |
Posted - 03 Jun 2011 : 23:08:06
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Thanks very much for the detailed reply Cliveshep.
I got this from the "Norman Range" section of the website.
It recommends that the Norman 17 requires a long shaft outboard.
Judging from the reply from Cliveshep, I wonder could I bring this to the attention of the person with responsibility for updating this website. Of course there were a number of different models (Mk 1,2,3) so perhaps the top of the transom to bottom of transom is longer than 16 inches on certain models of the Norman 17.
Thanks again Cliveshep for answering my question. I have seen in previous posts on this website such statements as, "all Normans require a longshaft"
If any other Norman 17 owners could post what size engine they are using on their boats it would be very helpful. At the moment it looks like my best bet is a 15hp four stroke short shaft.
"Norman Range"
Specifications
Overall Length 17'
Overall Beam 6' 4"
Headroom 5'
Overall Depth 5' 6"
Weight (complete) 740 lbs (335.66 kgs)
Draught 12"
Engine Recommendations (Longshaft)
Inland waterways 5 - 10 hp
River, estuary 10 - 18 hp
Coastal 18 - 45 hp
There were three versions of the Norman 17, Mk's l, ll and lll
The Mk lll claims to have a larger raised foredeck, flared bow and increased keel. |
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Norman 17, The long and the short of it?
