[C38] three blade fixed propeller

Mon Oct 10 23:10:42 EDT 2005

This discussion on props and boat speed is perfect timing. I am thinking
about replacing my prop again. My experiences are as follows, When I bought
the boat it had a 14x12 three blade fixed prop. I could only motor at 5.8 t0
6.2 at 2400 rpm(depending on sea state). I also couldn't get the engine to
reach max rpm.I think about 2500 is all it would turn. I re-pitched the prop
to 14x10. It helped with rpm, about 2600-2700,but I lost some boat
speed,About 5.7-5.9. Well, I did a little research and decided to purchase a
Campbell sailor prop. They recommended a 14x10 base on a reduction of 2:1 I
installed it and was tickled to death. I could motor at 7.0-7.2 at 2400 rpm.
Then one day I decided to see what she would do a full throttle. Well,at
2400 I was at full throttle,2400 was all that the engine would turn.Started
checking around and found that my transmission was a 1.8:1. Called Campbell
and they suggested repitching to 14x8(should get 200rpm for ever inch of
pitch) well, I only got 200 more rpm and lost 1.5 kts of boat speed,Now I
could only motor at 5.3-5.5 kts at 2400 rpm. Next in a long line of things
to happen I had to replace the transmission. This time I installed a PRN
tranny with a 2:1 reduction. Back to the yard to haul the boat again and
pitch the prop again,this time to 14x9.5 Now I motor at 5.9-6.0 kts and
still can not reach max rpm. The transom stays sooted from overloading the
engine. Although I like the Campbell prop[,I think it is to much prop for
the old 5424 to turn to its max rpm. I am now scratching my head trying to
figure out what would be the best prop for our engines that will let it
reach max rpm and still give better than 6 kts.
Moonraker C38 #204

--- Original Message ----- 
From: "Rob Cornelsen" <robcornelsen at yahoo.com>
To: "Catalina 38 Listserve" <Listserve at catalina38.org>
Sent: Monday, October 10, 2005 3:29 PM
Subject: Re: [C38] three blade fixed propeller

> Wow 5.5 at 2500! I get 4.8 at 2500 - 5.4 at 2800
> (REDLINE)with 2 bladed Martek folding prop and 2:1
> reduction gear.
>
> This spring I replaced my old Hurth gear box with a
> new ZF Hurth transmission which is the exact match as
> the original model with 2:1 reduction gear as per
> Catalina38.org site.  At the time the sales rep stated
> that 2:1 WAS NOT CORRECT SINCE I WAS ONLY MANUFACTURED
> SINCE LAST YEAR. They recommended 1.79 gear since it
> was marked with 2:1 on the old case.  Anyway I
> purchased the 2.05 (Not Bright the propeler rotation
> is now reduced to 87% of original).
>
> Rob #223
>
> Useful link
> http://www.tadiesels.com/ZF_10_M.html
>
>
>
>
> --- "Duff, Russ (R.W.)" <rduff at visteon.com> wrote:
>
> > Wow!  6.5 knots at 1800 rpm?!  I'm lucky if I get
> > 5.5 knots at 2500rpm with
> > my feathering prop.
> >
> > Sincerely,
> > Russ Duff
> > Catalina 38, Hull #112
> > "AVANTURA"
> > Lake Erie
> > Grosse Ile, Michigan
> > RDUFF AT VISTEON DOT COM
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: Listserve-bounces at catalina38.org
> > [mailto:Listserve-bounces at catalina38.org] On Behalf
> > Of empty
> > Sent: Monday, October 10, 2005 2:14 PM
> > To: Catalina 38 Listserve
> > Subject: Re: [C38] three blade fixed propeller
> >
> >
> > Hi Max,
> > The Goose has a bronze 14 x 12 fixed three blade
> > prop installed in 2004.
> > Pushes her along fine at 6.5 knots at 1800rpm on her
> > original Universal for
> > hour after hour. best wishes. Mark
> > ----- Original Message ----- 
> > From: "Max Soto" <maxsoto at hotmail.com>
> > To: <Listserve at catalina38.org>
> > Sent: Monday, October 10, 2005 6:55 PM
> > Subject: [C38] three blade fixed propeller
> >
> >
> > > Hi everybody,
> > >
> > > I'm plannig on buying a spare propeller for the
> > Estancia. I have the
> > > original 5424 with the original fixed two blade
> > 15"x13" (according to
> > > the 38org. specs.). I remember that there was some
> > mails a few months
> > > ago about Martec and
> > some
> > > other folding propeller, but none about fixed
> > ones.
> > >
> > > I read that a fixed three blade was an option from
> > Catalina. Do any of
> > > you know what's the three blade propeller number
> > for this boat with
> > > this engine????
> > >
> > > I'll really appreciate youy help.
> > >
> > > Max Soto
> > > C38 #198 ESTANCIA
> > > Puntarenas, Costa Rica
> > >
> > >
> >
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