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Scotland
Member
| Joined: | Wed Nov 19th, 2008 |
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| Posts: | 18 |
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Posted: Tue Feb 9th, 2010 11:29 am |
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Hello All
Has anyone fitted a folding/feathering propeller to an IP 320. I have fitted a Bruntons Autoprop which I have returned to the manufacturer fo reassessment as I am unhappy with the performance. IP have suggested contacting Variprop Maine
Peter
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djmarchand
Member
| Joined: | Tue May 27th, 2008 |
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| Posts: | 167 |
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Posted: Tue Feb 9th, 2010 07:25 pm |
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I have used three types of feathering props, and one folding prop in my boats over the years:
Martec folding two blade prop- This prop woud be fine for a cruiser/racer that only used its engine to get out of its slip. Simple and clean design, but doesn't work very well in reverse.
All of the following work equally well in forward as in reverse and one (the Prowell and maybe the Autostream, can't remember) lets you set the pitch independently for forward versus reverse.
MaxProp- Probably the most popular and I think the best. I think it is good because it has the highest DAR- developed blade area of the three (fat, wide blades) which means it is less likely to cavitate under heavy load. DAR is the ratio of the blade area to the disk area. It is available in a model that doesn't require removal to change the pitch.
Autostream- This is a very nicely made SS prop from Downunder. The only negative is narrow blades which contributes to cavitation under heavy load. I had one in a high performance Saga 43. It worked fine 95% of the time, but when I had to power into a head sea and the boat speed was diminished as a result, it cavitated. I attributed this to the narrow blades and a low DAR as a result.
Prowell (similar to the Variprop)- No longer made but a good all around feathering prop with something in between the MaxProp and the Autostream for DAR.
Each are available with the abiliity to change the pitch without removing, but it will take a diver to do this. Unless you know the exact diameter and pitch for your boat (and don't necessrily listen to the prop manufacturers, listen to owners for their recommendation) then it is worth getting the easily adjustable model. One haulout fee will cover the difference in costs.
The other issue is two blade versus three, at least for the MaxProp. If you intend to do a lot of motoring (and you will if you are cruising on an IP) then get the three blade. Again the three blade has a higher DAR (for a given diameter) and will perform better under power. You will lose a slight bit of performance under sail versus the two blade.
What didn't you like about your Autoprop? Other than bearing wear which requires rebuilding periodically I have heard, it seems like a nice solution- autopitching and autofeathering. Reversing takes a second or so for the blades to stop and flip over and it probably has a bit more drag under sail.
David
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dancline
Member
| Joined: | Sun Aug 8th, 2004 |
| Location: | Midland, Michigan USA |
| Posts: | 136 |
| Model: | IP320 | | Hull #: | 47 | | DSC ID: | |
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Posted: Tue Feb 9th, 2010 09:05 pm |
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| Please elaborate on the problems you have had with Autoprop. My boat, an IP320, has had an Autoprop installed since 2001 and it has performed admirably for me. So far the maintenance has been greasing the bearings once a year when the boat is hauled out. It's good to know what I may need to watch out for in the future, though.
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Dan Cline
Wildwood, IP320-47
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Long Shot
Member
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Posted: Tue Feb 9th, 2010 11:01 pm |
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I two have had an autoprop since 2000. grease it yearly and its been great.
IP380-97
LongShot
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Scott Campbell
Long Shot IP380-97
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Architeuthis
Member
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Posted: Wed Feb 10th, 2010 01:20 am |
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I've heard good things about Vari-prop but we have a Max-prop.
Max prop has worked well for us but adjustment is rather complicated. If I was getting a new prop I would get the type that can be adjusted with the boat in the water.
Full power in reverse has saved us a tow or two and prevented us from making contact with stationary items.
Here are some pics and info:
http://ip32.blogspot.com/2009/01/max-prop-info.html
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56 45.523n 111 28.603w
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Scotland
Member
| Joined: | Wed Nov 19th, 2008 |
| Location: | |
| Posts: | 18 |
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Posted: Wed Feb 10th, 2010 07:13 pm |
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Hello Dan,
The main problem is the engine cannot reach maximum revs, engine is rated at 3700rpm and with the autoprop only gets 3000rpm, it revs ok with the IP standard prop to 3700rpm. When butting into headwinds of 30 to 40 mph boat almost stops and you have to try zig zagging to make headway
Peter
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djmarchand
Member
| Joined: | Tue May 27th, 2008 |
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| Posts: | 167 |
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Posted: Wed Feb 10th, 2010 07:56 pm |
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Hi Peter:
If the only problem with your Autoprop is that it can't reach rated engine rpm, can't you ask Autoprop to replace it with a smaller one that will reach rated rpm? I certainly agree that 3,000 rpm is way too low. It also means that the prop is overloading your engine at lower rpms. I suspect you get some black smoke, certainly at 3,000 but even at 2,500 rpm.
I rather like the concept of the Autoprop and if I could get the right one for little or no money I would rather do that than spend $$$ on a new feathering prop.
Do you know the history of the Autoprop? Maybe it is apochryphal but the story that I read is that the British Navy wanted a prop that would work as well in reverse as forward to give their landing craft enough thrust to back off of the shore. Thus the Autoprop was born.
David
Last edited on Wed Feb 10th, 2010 08:10 pm by djmarchand
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Long Shot
Member
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Posted: Wed Feb 10th, 2010 08:33 pm |
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then you need to re adjust then pitch of the autoprop. this is simple when out of water.
I have worked with maxprops and they will have the same problem if they are not pitched correctly
Scott
IP380-97.
Longshot
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Scott Campbell
Long Shot IP380-97
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dancline
Member
| Joined: | Sun Aug 8th, 2004 |
| Location: | Midland, Michigan USA |
| Posts: | 136 |
| Model: | IP320 | | Hull #: | 47 | | DSC ID: | |
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Posted: Thu Feb 11th, 2010 02:28 am |
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| I wonder if your Autoprop is a little large for your boat. I have a Yanmar 3GM30F engine with a max RPM of 3400 on my IP320. I can hit that RPM on a good day, but at that pace I'm overpowering the boat. 2800 RPM provides a nice cruising pace at about 6 knots. Have Bruntons check their records on serial number AP4109RH and compare prop size with the one you returned. I'm a little surprised that the max rpm on your engine is so much higher than mine. Good luck.
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Dan Cline
Wildwood, IP320-47
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Scotland
Member
| Joined: | Wed Nov 19th, 2008 |
| Location: | |
| Posts: | 18 |
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Posted: Thu Feb 11th, 2010 01:22 pm |
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Thanks All
The gearbox fitted to my boat has a 3.2:1 reduction, how does that correspond with the gearbox for propeller no AP4109RH. The engine revs are taken from IP manual and have been checked so 3700rpm is correct for the the prop/gearbox
Peter
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dancline
Member
| Joined: | Sun Aug 8th, 2004 |
| Location: | Midland, Michigan USA |
| Posts: | 136 |
| Model: | IP320 | | Hull #: | 47 | | DSC ID: | |
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Posted: Mon Feb 15th, 2010 11:07 am |
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| Oops, 3400 rpm is the continuous power rating and 3600 rpm is the maximum rpm per the name plate on the engine. I quoted the wrong number in my last post, and meant to say 3600. The marine gear is the KM3P with a 3.2 forward gear reduction ratio. Last edited on Mon Feb 15th, 2010 11:17 am by dancline
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Dan Cline
Wildwood, IP320-47
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Scotland
Member
| Joined: | Wed Nov 19th, 2008 |
| Location: | |
| Posts: | 18 |
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Posted: Wed Feb 17th, 2010 09:19 pm |
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Hi Dan
What is the pitch and diameter of your prop
Peter
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dancline
Member
| Joined: | Sun Aug 8th, 2004 |
| Location: | Midland, Michigan USA |
| Posts: | 136 |
| Model: | IP320 | | Hull #: | 47 | | DSC ID: | |
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Posted: Wed Feb 17th, 2010 10:23 pm |
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| The stock prop supplied by Island Packet is specified in my manual as 18 x 11 x 1-1/4 RH 3 blade, which I think means 18" diameter and 11" pitch. I don't have the specs on the autoprop. Bruntons should know based on the serial number I supplied earlier. I'm not sure pitch is relevant to the autoprop since pitch is continuously variable.
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Dan Cline
Wildwood, IP320-47
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Scotland
Member
| Joined: | Wed Nov 19th, 2008 |
| Location: | |
| Posts: | 18 |
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Posted: Thu Feb 18th, 2010 11:47 am |
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Tnanks Dan
I wanted to compare your pitch with the one I was supplied with from Bruntons, The pitch is variable but if it is too coarse it will stop the engine getting full revs which is my problem, speaking to Bruntons again but I am not optomistic
Peter
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dancline
Member
| Joined: | Sun Aug 8th, 2004 |
| Location: | Midland, Michigan USA |
| Posts: | 136 |
| Model: | IP320 | | Hull #: | 47 | | DSC ID: | |
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Posted: Thu Feb 18th, 2010 01:24 pm |
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The prior owner of my boat, Glen Forbes, purchased the Autoprop in 2001. My guess is he obtained it from AB Marine, either directly or through the yacht broker, Holland Yacht Sales. You might try contacting AB Marine to see if they have records on it. Here is their web site: http://ab-marine.com/
Good luck!
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Dan Cline
Wildwood, IP320-47
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Spindrift
Member
| Joined: | Thu Jan 4th, 2007 |
| Location: | United Kingdom |
| Posts: | 89 |
| Model: | IP350 | | Hull #: | 132 ... | | DSC ID: | |
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Posted: Fri Feb 19th, 2010 07:57 am |
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This is the standard Autoprop model on the Autoprop database for standard configuration IP320: Yacht: IP 320 Autoprop Model: H5-460; Engine: Yanmar 3GM30 | BHP: 27 | RPM: 3600 | Gear Ratio: 3.2
If your engine is different the recommended model changes; if you send the details of your current engine to Autoprop they can tell if you have the correct model fitted.
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Duncan G
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Scotland
Member
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Posted: Mon Feb 22nd, 2010 02:57 pm |
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Thanks
This is the same engine and gearbox ratio will speak to Autoprop
Peter
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