Century or Century Plus?
Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo
Century or Century Plus?
I'm rebuilding a clutched Century long shaft to use as an auxiliary on my Freeman 22 cabin cruiser. My Century has the normal 4 bladed weedless propeller, but on my spares-donor machine I have the big low ration gearbox with the massive 5 bladed fan propeller, so would it be better to swap the lower units over? I'm looking for the auxiliary to provide steerage, not really much of a top speed, when used on the tidal Thames. The boat is 22 foot long, weighs about 1.5 tons fully loaded, has displacement hull with an inboard engine, and has quite a bit of windage from the cabin and canopy. What would you recommend - 4 bladed propeller, or the 'barge pusher'? I'm not too interested in absolute authenticity of the engine - more concerned with a working installation for the job I want it to do.
Re: Century or Century Plus?
Go Plus. It will give you the pushing power you need. But it will be slow.
TC - 1960 LLS - 1961 LLS - 1966 THCL - 1968 EFNRL - 1986
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Adrian Dale
- Posts: 758
- Joined: Wed Apr 16, 2014 7:58 am
- Location: Tasmania, Australia
Re: Century or Century Plus?
Steerage needs forward movement. To get good boat handling you need to have positive headway; so to answer your question, you need to assess the relative forward speed of both legs. Whichever gives you the best forward momentum will ultimately give you the best manoeuvrability.
Check the water line length of your vessel and use the following: 1 1/3 times the square root of the water line length = the maximum displacement boat speed
Assuming your vessel is say 18 feet on the water the maximum speed to be achieved will be 5.7 knots. Check out the two engines and compare the results against this calculated speed, which ever gives the best return is the answer to your question.
Don't confuse speed over the ground to speed through the water, do your testing at slack tides or do two runs with and against current and average the results. Have fun its great to experiment!
AJ
Check the water line length of your vessel and use the following: 1 1/3 times the square root of the water line length = the maximum displacement boat speed
Assuming your vessel is say 18 feet on the water the maximum speed to be achieved will be 5.7 knots. Check out the two engines and compare the results against this calculated speed, which ever gives the best return is the answer to your question.
Don't confuse speed over the ground to speed through the water, do your testing at slack tides or do two runs with and against current and average the results. Have fun its great to experiment!
AJ
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headdownarseup
- Posts: 2484
- Joined: Thu Apr 04, 2013 2:26 pm
- Location: bristol
Re: Century or Century Plus?
try the PLUS gearbox/prop combination.
I use a silver century plus with 4 blade weedless prop on my boat which is 17 foot, but as ADRIAN says it will be slow. (mine is too)
Have you thought about a different kind of outboard with more power? (something more like 10/15 hp might be a better bet for the size and weight of your boat)
experiment with the seagull first to see how it goes.
jon
I use a silver century plus with 4 blade weedless prop on my boat which is 17 foot, but as ADRIAN says it will be slow. (mine is too)
Have you thought about a different kind of outboard with more power? (something more like 10/15 hp might be a better bet for the size and weight of your boat)
experiment with the seagull first to see how it goes.
jon