[Amel Yacht Owners] Speed vs. RPM


Claude Roessiger <nearlynothing@...>
 

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


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Ag Av8ter
 

Hello Claude,
I spoke with a man in Ft. Lauderdale when I had our boat hauled out
for her survey. He owns an older Amel, not sure what model. He
suggested that as long as the boat was out of the water, that I
apply "some stuff" (I do not remember what it is called)> Evidently
it is a coating or film that goes on a squeaky clean prop an seals
it. Thus it is less apt to fouling and easier to clean when
fouled. I am an aviator, and there are "tapes" to cover the leading
edges of the wing and prop to accomplish this same thing. And for
rotorcraft it also reduces the leading edge errosion. When I get
back to my boat, in just a few days, I will try the full astern to
see what kind of RPM she will turn. In my particular case I am
convinced that the boat is over pitched, and that I am not getting
optimum performance from the turbo. (Low RPM, low to ineffective
turbine speed, thus increasing coking or carbon build up)

Tony Gray
WORLD CITIZEN SM #266


--- In amelyachtowners@yahoogroups.com, Claude Roessiger
<nearlynothing@...> wrote:

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


__________________________________________________
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Tired of spam? Yahoo! Mail has the best spam protection around
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Ag Av8ter
 

Hello Claude,
I spoke with a man in Ft. Lauderdale when I had our boat hauled out
for her survey. He owns an older Amel, not sure what model. He
suggested that as long as the boat was out of the water, that I
apply "some stuff" (I do not remember what it is called)> Evidently
it is a coating or film that goes on a squeaky clean prop an seals
it. Thus it is less apt to fouling and easier to clean when
fouled. I am an aviator, and there are "tapes" to cover the leading
edges of the wing and prop to accomplish this same thing. And for
rotorcraft it also reduces the leading edge errosion. When I get
back to my boat, in just a few days, I will try the full astern to
see what kind of RPM she will turn. In my particular case I am
convinced that the boat is over pitched, and that I am not getting
optimum performance from the turbo. (Low RPM, low to ineffective
turbine speed, thus increasing coking or carbon build up)

Tony Gray
WORLD CITIZEN SM #266


--- In amelyachtowners@yahoogroups.com, Claude Roessiger
<nearlynothing@...> wrote:

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


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ianjenkins1946 <ianjudyjenkins@hotmail.com>
 

Hi Claude and others. Sorry to read of your experience. I dont know if my Bruntons Autoprop is different to yours ( Pen Azen is June 2000, no 302, standard Volvo/Perkins engine) but after nearly 2,000 engine hours, usually cruising at 1900 revs with a burst of 2,800 for about ten minutes every 6 or so hours, I cen happily get 8.6-8.8 knots on a calm day with a full cruising load aboard.
Twice I have had the revs stick at about 2200 in gear even though I was getting 2800 in neutral. On each occasion the boat had just been put in the water after several months ashore. All I did on each occasion was to keep revving up and down for ten minutes or so and the thing cleared itself.
So far, performance hasnt been affected by small amounts of sealife. On one occasion, in UK waters, I couldnt exceed 7 knots at full throttle and on diving I found the prop absolutely covered in barnacles between one and two centimeters across. I was amazed that it functioned at all.
I confess that I have never seen how high I can rev astern, but going ahead I have found nothing to complain of.
Bruntons claim that you should think of changing the bearings after 1000 hours or so. I think this depends on revs and the condition of the water you sail in. I will do it next time the boat is out of the water. Fair winds, Ian and Judy Jenkins, Pen Azen, Rio de Janeiro ( just about the dirtiest water you can find!)

From: Claude Roessiger <nearlynothing@yahoo.com>
Reply-To: amelyachtowners@yahoogroups.com
To: amelyachtowners@yahoogroups.com
Subject: Re: [Amel Yacht Owners] Speed vs. RPM
Date: Wed, 8 Mar 2006 09:10:49 -0800 (PST)

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


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John McDougall <j.c.mcdougall@...>
 

Hi Claude & others
My SM2000 no 330 had the Yanmar/Autoprop combination and max revs
would frequently drop to about 1700. This was always cured by
cleaning the prop. My berth is in Antibes and the rate of marine
growth seems very high there for a reason we needn't go into but
let's say the harbour fish are large and fat. Quite expensive as I
don't dive (and certainly wouldn't in the marina!). The prop was
subject to a recall by Bruntons and in May 2004 I had Amel fit the
spare fixed blade prop. This prop is still fitted.

It is difficult to compare the performance of the fixed prop against
the Autoprop but I would say the difference is so slight as to be
unoticeable without making a test under identical conditions. I
agree that the Autoprop is extremely sensitive to fouling and I have
specified a fixed blade prop on my "54" to be delivered at the end
of this month.

Finally, before the fixed prop was fitted I had it treated with
PROPSPEED a silcone based propellor antifouling which works by means
of producing a slippery surface that marine gowth cannot adhere to.
The result was fantastic - the prop was still clean a year later as
opposed needing to be cleaned every couple of months in summer.
Propspeed is very expensive but I believe Seajet Pellerclean to be a
similar product and this has just been rated as the best in March
Yachting Monthly and Motor Boat
magazines. Has anyone tried it?
John McDougall


-- In amelyachtowners@yahoogroups.com, Claude Roessiger
<nearlynothing@...> wrote:

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


__________________________________________________
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Tired of spam? Yahoo! Mail has the best spam protection around
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Krassopoulos Dimitris <dkra@...>
 

I agree that the Autoprop is sensitive to marine growth but any propeller is
I think. Regarding SEAJet product I tried it without any good result. So I
do not recommend it.

My question to John : what was the speed difference with the autoprop and
the fixed propeller?

SM 2000 Alma Libre

Dimitris

-----Original Message-----
From: amelyachtowners@yahoogroups.com
[mailto:amelyachtowners@yahoogroups.com] On Behalf Of John McDougall
Sent: Monday, March 13, 2006 2:12 PM
To: amelyachtowners@yahoogroups.com
Subject: Re: [Amel Yacht Owners] Speed vs. RPM

Hi Claude & others
My SM2000 no 330 had the Yanmar/Autoprop combination and max revs
would frequently drop to about 1700. This was always cured by
cleaning the prop. My berth is in Antibes and the rate of marine
growth seems very high there for a reason we needn't go into but
let's say the harbour fish are large and fat. Quite expensive as I
don't dive (and certainly wouldn't in the marina!). The prop was
subject to a recall by Bruntons and in May 2004 I had Amel fit the
spare fixed blade prop. This prop is still fitted.

It is difficult to compare the performance of the fixed prop against
the Autoprop but I would say the difference is so slight as to be
unoticeable without making a test under identical conditions. I
agree that the Autoprop is extremely sensitive to fouling and I have
specified a fixed blade prop on my "54" to be delivered at the end
of this month.

Finally, before the fixed prop was fitted I had it treated with
PROPSPEED a silcone based propellor antifouling which works by means
of producing a slippery surface that marine gowth cannot adhere to.
The result was fantastic - the prop was still clean a year later as
opposed needing to be cleaned every couple of months in summer.
Propspeed is very expensive but I believe Seajet Pellerclean to be a
similar product and this has just been rated as the best in March
Yachting Monthly and Motor Boat
magazines. Has anyone tried it?
John McDougall


-- In amelyachtowners@yahoogroups.com, Claude Roessiger
<nearlynothing@...> wrote:

I have had no end of trouble with this combination.
Amel aren't playing this straight with us. Every owner
I have met with the Volvo-Auto prop combination has
similar woes. I think the source of the trouble is the
prop. In reverse, do you get 3500 RPM? If so, it says
a lot.
This darned prop (and I have had unsatisfactory
exchanges with Bruntons, the maker) is unbelievably
sensitive. Unless it's polished to perfection, it
seems to just not give power. Expensive as it is, I
think to change it.
At full power the SM ought to give you 8 kts +.
I have had similar woes in waves as you describe, no
power, no speed.
The Volvo turbo-diesel is itself less torquey than a
straight old diesel as in the old Maramus,
bullet-proof engines.
This said, an 80 hp engine should do the job. I think
the prop is suspect.
If anyone has made a prop change successfully, it
would be good to know.
Thanks,
Claude Roessiger


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