[C320-list] Prop Info

[John Van Vessem]

Len,

Something is different with your boat and mine.  I have a factory fixed 3 blade and I do 7 kts at 2900 RPM.  I wonder if the SOG you are measuring is against the current, then your actual boat speed would be faster than 7 kts.
 
John Van Vessem
Sojourn 645
Vallejo Yacht Club



----- Original Message ----
From: Len <aqua5len at gmail.com>
To: C320-List <c320-list at catalina320.com>
Sent: Tuesday, November 7, 2006 10:23:35 AM
Subject: Re: [C320-list] Prop Info


Re Maverick---Have you checked your engine rpms with photo tachometer?  I
found indicated rpms about 250 rpm below actual; will recalibrate soon.
Also, at max throttle 3600 actual, my boat does 7 knots (per gps sog) with
standard factory 3-blade 15x*11*.

Len Krane
Aqua5   #1070.


On 11/7/06, Bob & Bel Harrison <b_harrison at shaw.ca> wrote:
>
> Earlier this year we installed a 15" Three Blade Classic Max-prop to
> replace
> a 15x9 3-blade fixed prop.
> Engine is a Yanmar 3YM30, standard transmission.
> The prop was set to the manufacturer-recommended 10.3 (20 degrees) pitch,
> and here are some before & after boat speed measurements...
>
> RPM   Fixed   Max-prop
> 2300    4.4    4.6
> 2600    4.85   5.13
> 2900    5.35   5.65
> 3200    5.8    5.95
> 3500    6.0    6.28
>
> It seems to me that since the engine has no difficulty reaching high RPMs,
> the prop could be pitched a little higher, say 11.4 (22 degrees).  I'm
> considering changing it at next spring's haul-out, but on the other hand,
> why mess with something that's quite satisfactory?
>
> Bob Harrison
> Maverick #1007
>
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Jeff Church
> Sent: November 6, 2006 11:06 AM
> To: C320
> Subject: [C320-list] Prop Info
>
> The boats on the hard and I'm working thru my winter project list. I'm
> about
> to re-pitch my MaxProp and I'd like to know what pitch other 320 owners
> are
> using. MaxProp's database is out of date. They only list the C320 with a
> Perkins diesel.
>
> If you have a MaxProp and a Yanmar please let me know the pitch,
> transmission ratio, and your maximum speed and RPM while motoring.
>
> Aside from taking the results into account for my use, I'll update MaxProp
> with the information.
>
> Thanks
>
> JeffC
>
>
>