[Public-List] Public-List Digest, Vol 3273, Issue 2
Gordon Laco via Public-List
public-list at lists.alberg30.org
Mon Jun 6 05:19:00 PDT 2016
I don't doubt that. In any case, we're calling the exercise a success.
G
On 2016-06-06, at 8:06 AM, <sail_505 at hotmail.com> wrote:
> Gord,
>
> The quietness is probably a result of less prop-wash against the hull due to the reduced diameter. With an aperature, like the A30, the prop should be no more than 85% of the aperature...the original 13" prop was nearly all of the opening.
>
> Mike Lehman
> ~~/)~/)~~
>
>
>
> On Sun, Jun 5, 2016 at 6:05 PM -0700, "Gordon Laco via Public-List" <public-list at lists.alberg30.org> wrote:
>
> Hello friends,
>
> Found it already. The old prop, factory installed at Whitby Boatworks, is a
> two blade 'Columbian' 13 diameter x 7 pitch.
>
> The new Campbell prop is 11 x 5.
>
> As I wrote below, the Campbell prop is very different. The blades are thick
> in cross section with rounded somewhat blunt leading edges, not sharp. Each
> blade is quite a bit narrower than each of the old two blade prop's blades.
> The aggregate result is that although there are three blades, there's only
> something like 20% more area than the traditional two bladed prop.
>
> My understanding of the quietness is that there is never a time when more
> than one third of the area of the prop is masked by the sternpost... So I'm
> not getting that 'whomph' caused by BOTH blades being masked, all the area,
> twice every rotation.
>
> I'll send a picture of the new prop if people write me off line.
>
> Gord Surprise 426
>
>
> On 2016-06-05, 8:28 PM, "charles pleisse via Public-List"
> <public-list at lists.alberg30.org> wrote:
>
> > Gord,
> > Was your new Campbell prop a 2 or 3 blade prop?
> > Charlie
> > Sookie 221
> >
> > Jun 5, 2016 at 3:05 PM, via Public-List <public-list at lists.alberg30.org>
> > wrote:
> >
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> >> Today's Topics:
> >>
> >> 1. Re: Propellers... (Gordon Laco via Public-List)
> >>
> >>
> >> ----------------------------------------------------------------------
> >>
> >> Message: 1
> >> Date: Sun, 5 Jun 2016 14:12:52 -0400
> >> From: Gordon Laco via Public-List <public-list at lists.alberg30.org>
> >> To: Don Campbell <dk.campbell at xplornet.ca>
> >> Cc: Alberg 30 Public List -- open to all
> >> <public-list at lists.alberg30.org>
> >> Subject: Re: [Public-List] Propellers...
> >> Message-ID: <7CF3D811-D6FB-4664-8C6F-F8423E87C99C at csolve.net>
> >> Content-Type: text/plain; charset=utf-8
> >>
> >> Hi Don
> >>
> >> It's 3x as per Campbell standard for our boats. Pitch and diameter are
> >> also as per their advertised standard made for our boats, engines and
> >> transmission ratio
> >>
> >> G
> >>
> >> On 2016-06-05, at 2:01 PM, "Don Campbell" <dk.campbell at xplornet.ca> wrote:
> >>
> >>> The only things you have not given us is the diameter and pitch of this
> >> new machine! I am guessing a two blade because of your comment on the stock
> >> blade from Whitby B.W. but not sure on that either.
> >>> Don Campbell
> >>>
> >>> -----Original Message----- From: Gordon Laco via Public-List
> >>> Sent: Sunday, June 05, 2016 11:44 AM
> >>> To: George Dinwiddie ; Alberg 30 Public List -- open to all
> >>> Subject: Re: [Public-List] Propellers...
> >>>
> >>> Thanks,
> >>>
> >>> Caroline laughed at me over the battery charger/charge state thing.
> >> When I
> >>> noticed it had clicked off, I assumed a malfunction so went into 'grumpy
> >>> Gord' mode.... 'damned thing, what next, knew something would go wrong,
> >> hate
> >>> batteries, when I am going to find time to fix this, probably five things
> >>> wrong, not just one...' etc etc until I realized that the issue was that
> >>> the batteries were indeed fully charged...
> >>>
> >>>
> >>> On 2016-06-05, 11:11 AM, "George Dinwiddie via Public-List"
> >>> <public-list at lists.alberg30.org> wrote:
> >>>
> >>>> Sounds like a complete win, Gord.
> >>>>
> >>>> On 6/5/16 10:42 AM, Gordon Laco via Public-List wrote:
> >>>>> Hello friends,
> >>>>>
> >>>>> I?m sorry to reintroduce this topic... But I?ve changed propellers and
> >>>>> thought I?d share the experience.
> >>>>>
> >>>>> Some of you may recall that I have pontificated about taking a ?don?t
> >>>>> change? position with regard to the prop supplied by Whitby Boatworks
> >> with
> >>>>> the Atomic IV engines many of our boats have.
> >>>>>
> >>>>> Well this spring I was thinking about the engine and decided to try a
> >>>>> change. Last fall?s ?Misery Trip? reached a crescendo of suffering
> >> with a
> >>>>> slog to windward in 40 knot winds and a sharp chop... We were nearly
> >>>>> stopped a few times, mostly by wave action, but SURPRISE trudged along
> >> and I
> >>>>> would say coped better than our companion?s boats which were all fin
> >> keeled
> >>>>> yachts fitted with diesels. So power delivered to the water wasn?t
> >> the
> >>>>> issue... What I was thinking about was alternator performance and
> >> cooling.
> >>>>>
> >>>>> Cooling has never been an issue with our engine, particularly since I
> >>>>> replaced the old water pump with the upgrade offered by Moyer.
> >> However I?ve
> >>>>> been keenly aware that our cruising RPM of about 1000 doesn?t really
> >> spin
> >>>>> things down in the engine compartment fast enough to deliver what the
> >>>>> alternator is theoretically capable of.
> >>>>>
> >>>>> I liked the look of the narrowed bladed ?Campbell? props I?d seen on
> >> other
> >>>>> boats, and liked the idea of increasing revs while at least keeping
> >> the same
> >>>>> ?power in the water? situation the stock two bladed prop gave us. So I
> >>>>> ordered the Campbell which they recommend for Alberg 30?s fitted with
> >> Atomic
> >>>>> IV engines with 1:1 transmissions. The vendor said he was certain
> >> what
> >>>>> shaft diameter and taper my boat has... But because I?m a doubter, I
> >> sent
> >>>>> him my old prop for reference.
> >>>>>
> >>>>> In due course the new prop came back along with the old one (and he was
> >>>>> right, he did already know the specs). I couldn?t wait to try it out.
> >>>>>
> >>>>> We installed the new prop as part of my condensed spring outfitting
> >> (and no,
> >>>>> I did not do the cap rail job I wrote about earlier. I got busy with
> >> work
> >>>>> which took me away most of April and May so that?s that on that job for
> >>>>> now). Eagle eyed Rod saw the shiny new thing and commented ?I thought
> >> you
> >>>>> said...? Well I know what I said, but what the heck...
> >>>>>
> >>>>> We got SURPRISE into the water and after securing the rig, started up
> >> and
> >>>>> started the two hour trip back to our sailing club. First thing I
> >> noticed
> >>>>> was that I seemed to have a lot more power in reverse than before. The
> >>>>> second thing was that prop walk seemed to have dissappeared... Amazing.
> >>>>>
> >>>>> The only negative comment I?d read about these props on line referred
> >> to a
> >>>>> supposed loss of maneuvring power... But I was able to do the usual
> >> spin
> >>>>> within her length that SURPRISE normally does. Motoring out of
> >>>>> Dutchman?s Cove Marina, I found that our speed at idle was lower, and
> >> that?s
> >>>>> a good thing of course not unexpected because of the finer pitch.
> >> Once out
> >>>>> past the breakwater, we opened the throttle and both Caroline and I
> >> were
> >>>>> amazed. Boat speed climbed to 6.6 knots as usual for full throttle,
> >> but
> >>>>> there was no roar and vibration from the engine. I won?t say it was as
> >>>>> quiet as electric, but the change from how things were was startling
> >> and
> >>>>> dramatic. We were so quiet at full speed I mistrusted the knotmeter
> >> and
> >>>>> fired up the GPS, but it confirmed the speed. Amazing.
> >>>>>
> >>>>> We found our old cruising speed of 5.2 at 1000rpm was now 5.2 at 1400
> >> (this
> >>>>> second RPM was full out open throttle with the old prop). Yes the
> >> engine was
> >>>>> spinning faster, but at the same throttle setting and clearly not
> >> labouring
> >>>>> quite so hard. The boat was so quiet we didn?t feel like we were
> >> moving,
> >>>>> so we did the trip at 6+.
> >>>>>
> >>>>> So the prop change is rated a total success. But there was a surprise
> >> in
> >>>>> store for us. Because I was away so much I didn?t do my usual thorough
> >>>>> recharge of the batteries... We started up after launch on what was
> >> left in
> >>>>> the batteries after the Misery Trip and months of winter lay up. I
> >> was
> >>>>> glad there seemed to be enough juice to spin the engine.
> >>>>> Yesterday I decided to connect up the battery charger and run it all
> >> day...
> >>>>> But after only moments, the charger was indicating full charge. I
> >> assumed a
> >>>>> problem with the charger but after investigating, realized that the
> >>>>> ?problem? was that the battery bank was indeed fully charged and the
> >>>>> automatic function on the charger was sensing this and shutting off.
> >>>>>
> >>>>> How could that be, I thought... Then it occurred to me that the
> >> alternator
> >>>>> must have run up the batteries on the trip over from the marina. In
> >> the old
> >>>>> days, the alternator barely kept up with the engine?s requirements and
> >> I?d
> >>>>> had to charge from shore power periodically. So it appears that
> >> whatever
> >>>>> was in the batteries at launch, the engine itself topped them up in
> >> the 90
> >>>>> minute shot over under power (wasn?t two hours because we galloped home
> >>>>> faster).
> >>>>>
> >>>>> Happy happy.
> >>>>>
> >>>>> Gord #426 Surprise
> >>>
> >>>
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> >> End of Public-List Digest, Vol 3273, Issue 2
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