[C320-list] Prop Info
Robert E. Sloat
resloat at comcast.net
Thu Nov 9 10:32:35 PST 2006
What a great tip. I don't think there is any problem with my tachometer,
but will do this experiment just for the fun of it. And adjust if necessary.
Bob Sloat
Savannah #894
----- Original Message -----
From: <frpoint at earthlink.net>
To: "C320-List" <c320-list at catalina320.com>
Sent: Thursday, November 09, 2006 12:27 PM
Subject: Re: [C320-list] Prop Info
> you can use a florescent light. paint a single line on the front pulley of
> your engine.
> while shining the florescent light at the pulley slowly rev the engine. at
> 1800 rpm you should see 4 stationary lines adjust the tack at the binnacle
> to read 1800 rpm. note: use a shore power light, not 12 volt.
>
> ----- Original Message -----
> From: "Bob & Bel Harrison" <b_harrison at shaw.ca>
> To: "'C320-List'" <c320-list at catalina320.com>
> Sent: Thursday, November 09, 2006 10:16 AM
> Subject: Re: [C320-list] Prop Info
>
>
> Jeff,
> I just tried this, and got to maybe 4050 in neutral. I was aware that it
> wasn't supposed to go that high, which was the reason we asked the
> mechanic
> to check the tach. No hobby shop around here has heard of such a thing as
> an optical tach, and neither have the auto parts stores, at least under
> $400. My bicycle computer does basically the same thing and a lot more
> for
> about $30, so I don't know why a handheld tach should be any different.
> EBay
> has one for $10 plus $40 shipping, so I'll try a few more places here
> (Vancouver, BC).
>
> Bob H.
>
> P.S. After 3 summers, the boat has ~1050 engine hours, so we've probably
> used more oil for oil changes than Ken D. uses in diesel ;-). We're at 90
> days on the water so far, but it looks like we won't quite make 100 this
> year, as the ski season starts in a couple of weeks!
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Jeff Church
> Sent: Tuesday, November 07, 2006 7:41 PM
> To: C320-List
> Subject: Re: [C320-list] Prop Info
>
> Bob,
>
> I can't even get to 3900 in neutral, but the maximum no-load rpm spec is
> 3850 so maybe your tach is off. If you want to check it, you can buy a
> optical tach at a hobby shop for $25.
>
> I spoke with a different MaxProp tech today and got a different answer
> regarding the correct pitch. This guy says 16 degrees would be a good
> setting for cruising conditions. I knew if I called enough I'd eventually
> get the answer I was waiting for.
>
> I'm surprised that there aren't more MaxProp owners on this mail list!
>
> Jeff
> ----- Original Message -----
> From: Bob & Bel Harrison
> To: 'C320-List'
> Sent: Tuesday, November 07, 2006 9:01 PM
> Subject: Re: [C320-list] Prop Info
>
>
> My transmission ratio is 2.62.
> We can reach 3900 RPM, but it starts to heat up very quickly over 3300,
> so
> we usually motor for long stretches around 2800. Only if necessary, of
> course. Once in a while we run at high RPM for 5 minutes or so, as
> Yanmar
> recommends.
> It sounds like we both should re-pitch - - yours lower and mine higher.
>
> Bob H.
>
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Jeff Church
> Sent: Tuesday, November 07, 2006 2:46 PM
> To: C320-List
> Subject: Re: [C320-list] Prop Info
>
> Bob,
>
> Thanks for the information.
>
> You have more pitch than me and yet you are running at a higher rpm than
> I
>
> am. Do you know what your transmission ratio is? If yours is 2.62 that
> would
>
> explain the difference between your rpm and mine. I believe Catalina used
> a
> couple of different ratios. I have the 2.21 transmission and with 18
> degrees of pitch I turn 3500 rpm at 7+ knots in flat calm conditions.
> Also,
> what is the maximum rpm you can get at full throttle?
>
> My current pitch is OK for day-sailing, but I'm considering re-pitching
> to
>
> 16 degrees so I can still get 3500 to 3600 rpm under less than ideal
> cruising conditions such as fully loaded boat, fouled bottom, headwinds
> and
> big seas. When I go on a long cruise those are the usual conditions when
> I
>
> would need to motor near full speed. As currently pitched, that kind of
> load
>
> pulls my max rpm down to around 3000 and the engine gets a bit stressed.
> MaxProp thinks I shouldn't need to re-pitch, Yanmar thinks I should.
>
> Jeff
>
>
> ----- Original Message -----
> From: "Bob & Bel Harrison" <b_harrison at shaw.ca>
> To: "'C320-List'" <c320-list at catalina320.com>
> Sent: Tuesday, November 07, 2006 11:51 AM
> Subject: Re: [C320-list] Prop Info
>
>
> 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
>
>
>
>
>
>
>
>
>
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