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geezee
United Kingdom
24 Posts |
 Posted - 23 May 2019 : 19:00:21
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Hi everyone,
Bit of a tecchie query, but does anyone know the correct propeller and pitch size for an Enfield Z Drive? The drive is attached to a BMC 1500 diesel engine which, in turn, is attached to a Norman 32. The current prop/pitch is a 14 x 9, but I have been led to believe that this is the wrong size. The boat does struggle, or rather I do, when coming into mooring and I have been informed that a different size/pitch of prop may lead to better control. Maybe I'm just a lousy helmsman!! Any assistance would be gratefully received.
Gee Zee |
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df
United Kingdom
5994 Posts |
Posted - 23 May 2019 : 19:59:22
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What sort of rpm do you get at what speeds? 14 x 9 is a fairly low pitch prop for a 1500 diesel I would have thought.
If it's any use my old rlm 31 had 14 x 14 on bmc 2.5's and when I fitted 1900 peugeot's 14 x 10 seemed to give me a comfortable hull speed at 2000 rpm which is where peak torque was produced, that was a twin engine boat though.
Do you get much flow where you moor? If so always moor against it and it will be easier.
Props are a bit of a black art to get right.
NBAS--The communal colostomy bag of the boating community.
 Visit leomagill.co.uk |
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stratford4528
United Kingdom
414 Posts |
Posted - 24 May 2019 : 07:42:22
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| Chertsy Marine are very good at helping. They are enfield agents and supply parts. 01932 564699. I have a 25 hp Kubota in my 32 so my prop size will be different. |
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df
United Kingdom
5994 Posts |
Posted - 24 May 2019 : 08:10:01
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If steering control at low speed is the issue how about an add on rudder to the drive, there was one called add-a-rudder but home fabricated wouldn't be too difficult to do.
NBAS--The communal colostomy bag of the boating community.
Visit leomagill.co.uk |
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geezee
United Kingdom
24 Posts |
Posted - 24 May 2019 : 18:29:06
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Many thanks for your various recommendations. It has confirmed my thoughts that the current prop is somewhat inadequate. Thanks Leo for the 14 x 10 recommendation. This has also confirmed what I thought might be needed. As you say, it is something of a black art!
Gee Zee |
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df
United Kingdom
5994 Posts |
Posted - 24 May 2019 : 19:15:24
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Changing to 14x10 will bring the rpm down and the speed up a bit, what is the problem you are having?
Does the engine acheive full rated rpm at full throttle?
NBAS--The communal colostomy bag of the boating community.
Visit leomagill.co.uk |
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cliveshep
Thailand
1324 Posts |
Posted - 27 May 2019 : 03:41:07
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32 feet is not going to steer like a taxi whatever prop you fit, but having a prop that allows your engine to reach max revs/torque will give you the best chances.
Having said that using wind and current and "prop-walk to your advantage will help a lot too as will lining up while you still have "sea-room" to make changes.
Sometimes mooring needs coming in on a spring to get alongside, for example on a windward pontoon putting a line onto the nearest end from the bow and going ahead will pull the boat in as the line goes tight. Lots of tricks to helm a stubborn boat and your 1500cc engine and stern drive will give you more control than any outboard.
Finally living the dream!
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PROPELLOR AND PITCH SIZE
