[C320-list] Regatta Tech Sessions - a summary.

[Jeff Church]

Bruce,

I have a MaxProp so I can't recommend what should happen with an Autoprop, 
but my recent experience could be helpful to you. I recently had Mack Boring 
come out and inspect the engine because I have not been able to get the 
engine up to 3600 RPM. I thought the prop was pitched correctly and I was 
able to get 3600 at the beginning of the season, so I suspected an engine 
problem. The interesting thing to note is that they found that my tachometer 
is very inaccurate. They said that this is common, and I have read about 
this problem from other owners on this mail list. If yours is indicating 
3300 RPM, it may be that it is really turning 3000 or 3800 RPM. 
Unfortunately, when we measured with an optical tach we found that my engine 
is turning even slower than the boat's tach indicates, so I'll need to 
re-pitch (and fix the tach). Before you do anything with the prop, you might 
want to purchase an optical tachometer at a hobby shop for $30 dollars (they 
use them to measure propeller speed on RC planes) and see what your real 
engine speed is.

FYI
1) Mack Boring also recommends pitching the prop for dirty bottom/fully 
loaded conditions.
2) Yanmar has a spec for no-load wide open throttle (something like 4500 
RPM). If you can't get up to that RPM you might have an injector or fuel 
pump problem that is keeping you from hitting 3600 under load.

JeffC


----- Original Message ----- 
From: <bruceheyman at cox.net>
To: "C320-List" <c320-list at catalina320.com>
Sent: Tuesday, September 12, 2006 2:05 PM
Subject: Re: [C320-list] Regatta Tech Sessions - a summary.


> Jon,
> Would be interested what others can get the autoprop up to.  When I tried 
> it yesterday iit only made it up to 3300 or so.  I'd also be interesting 
> what everyone considers the proper crusing RPM.  At the regatta I heard 
> everything from 3000 to 2100.  I always heard that desiels do best at 80% 
> of red line.  I've looked theough the owners manual and the shop manual 
> for the 3GM30F and they offer no insight.
> Thanks,
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry from Cingular Wireless
>
> -----Original Message-----
> From: jonvez at comcast.net
> Date: Tue, 12 Sep 2006 17:37:42
> To:catalina at thehares.com, C320-List <c320-list at catalina320.com>
> Subject: Re: [C320-list] Regatta Tech Sessions - a summary.
>
> Jeff,
>
> Thanks for the recap, very good info. all around....A couple of items from 
> the Yanmar discussion certainly stand out--certainly the comment on the 
> Dexcool and also getting the engine up to 3600 regardless of the 
> prop...not sure I can do that with my Autoprop....
>
> Thanks again for keeping those of us who could not make it informed...
>
> Regards,
>
> Jon
>
> -------------- Original message -------------- 
> From: "Jeffrey Hare" <catalina at thehares.com>
>
>> Hi All,
>>
>> At this year's regatta, Dick organized tech sessions by:
>>
>> * Mark Felgenhauer at Garhauer Marine,
>> * A technical guy from Lewmar,
>> * A Yanmar technical representative
>> * Some riggers demonstrating how to tension and adjust the mast rigging 
>> on a
>> C320.
>>
>> This is about all I remember from those sessions. If you attended and 
>> have
>> things to add or corrections to make, please feel free to note them and 
>> make
>> corrections. I'd like to post as much information from the tech sessions 
>> as
>> possible on the website, but since I didn't take any written notes, I
>> probably forgot about lots of things that were discussed. I may also have
>> made some mistakes below in trying to write this email, so "have at it!".
>>
>>
>> GARHAUER:
>> =========
>> The session with Garhauer was an interesting opportunity to see the new
>> products they've introduces for the C320, and ask tech questions about
>> applications. One of the most interesting new products is the replacement
>> Genoa turning block for the one in the cockpit near the primary winches. 
>> It
>> is a beautifully manufactured block that's a perfect replacement for the
>> stock Lewmar one. The main difference is that the Garhauer block has
>> bearings and handles the sheet loads way better. It's beautifully
>> anodized and machined from an aluminum block.
>>
>>
>> LEWMAR:
>> =========
>> The Lewmar rep, discussed how to disassemble the side hatches, stop leaks
>> and adjust the latch mechanisms. He discussed the 4 types of side hatches
>> used on the C320, and showed the new Stainless Steel framed replacement
>> hatch used on the current and future C320s. He also indicated that Lewmar
>> now makes all the hatches on the C320, so at some point the forward hatch
>> went from being a Bomar, to a Lewmar. It would be interesting to know 
>> when
>> this change occurred.
>>
>> My observations: (from memory)
>> There are two shapes for the standard side hatches. Rectangular Ends &
>> Rounded Ends.
>>
>> As a common note, he indicated that replacement inside rubber seals on 
>> the
>> side hatches are available and replaceable if they're damaged and leak, 
>> but
>> keeping them clean and having the closing tension properly adjusted 
>> (where
>> possible) should eliminate leaking through this seal.
>>
>> Rectangular End side hatches:
>> ==========================
>> Used on the Earlier C320's (prior to ~2000??), and have the twist style
>> of hatch closure.
>>
>> There are two styles of outside frame for these. The older style has a
>> horizontal seam in the center of each end, and those that have a single
>> vertical seam at the bottom. The older styles were prone to the sealant 
>> in
>> the seams drying out and allowing water to enter the hatch frame, and 
>> leak
>> inside. He had a procedure that would help eliminate or reduce that
>> leakage. The newer version of the rectangular hatch had a vertical seam 
>> on
>> the bottom and was far less prone to leaking. But he said, to pull the
>> inner trim ring and if you see water in there after a rain, then the 
>> rubber
>> in the outer seal is probably leaking. Someone who took notes, may have
>> more details here.
>>
>> He indicated that there were a couple versions of the twist lock
>> closures on the rectangular frames. Ones that had the catches welded, and
>> others that had the catches screwed in. He had a procedure that would let
>> you adjust the closing tension here.
>>
>> Rounded End side hatches:
>> =======================
>> Used on the newer (post ~2000-ish?) C320s and have the flip up/down
>> hatch closures.
>>
>> Lewmar has made a few different versions of these side hatches, with the
>> differences being mostly in the appearance of the finish on the aluminum
>> outside trim.
>>
>> The newest version has a SS outside trim ring and looks very nice. The
>> rounded end hatches can be directly replaced with the current polished
>> Stainless Steel side hatches since the sizes and hull opening 
>> requirements
>> are identical. They are not a direct replacement for the squared end side
>> hatches however. I forgot to ask about whether they have better side
>> screens on the new SS hatches.
>>
>>
>>
>> YANMAR:
>> =========
>> He mentioned quite a few things. Some of them I remember, most of
>> them I don't. :)
>>
>> * Again, he reiterated that regardless of which prop you have, the
>> engine needs to be able to reach 3600 RPM under load or the prop is
>> overpitched.
>>
>> * He indicated that a 2 micron filter was a good idea and that the
>> engine and pump has absolutely no difficulty with this fine a filter. I
>> mentioned (after his presentation was over) the discussions this list has
>> had and the concerns some raised about not getting a good enough flow 
>> with
>> 2u filters. He said that the engine is efficient and doesn't need to move
>> lots of fuel, so fuel starvation isn't going to happen just because you 
>> use
>> a 2u filter. He indicated that the difference in fuel flow through 2 and
>> 10 micron filters is really quite minimal. He indicated that the finer
>> filter is better for the injectors and that 2micron is stock for newer
>> yanmars anyway. Filter size does matter in really cold (below freezing)
>> weather where diesel gelling issues are possible. But I'm tucked in at 
>> home
>> beside the fireplace in those conditions anyway. :)
>>
>> * He discussed the differences in the 3YM vs. 3GM. Mainly that the
>> seawater impeller is easier to change.
>>
>> * He indicated that we should CHANGE our ANTIFREEZE to the DexCool
>> variety. He said yanmar found that the Green (and others?) were possibly
>> the cause of corrosion in the aluminum parts of the heat exchanger. 
>> Yanmar
>> is using DexCool in these engines exclusively now. (Please correct me if 
>> I
>> missed something here). We discussed flushing it out, and he said that we
>> should try to get as much out as possible, but not to worry about small
>> amounts left in there, that small amounts mixing wouldn't be harmful.
>>
>> * He mentioned that the impeller should be checked every year, and
>> replaced every ?2?. (I forgot his exact answer, but he indicated that 
>> look
>> for wear and cracking.)
>>
>> * He cleared up the "impeller mystery" between the European and
>> Japanese Yanmars. He said that there are 2 different pump manufacturers.
>> Johnson, and Yanmar. The Yanmar pump, needs an impeller with the keyway 
>> and
>> a paper gasket. The Johnson pump uses a rubber O-Ring and has a slotted
>> shaft that accepts an impeller with a screw through the center of the 
>> hole
>> in the impeller. He indicated that the Japanese Yanmars typically (but 
>> not
>> always) used the Yanmar pump, while the European Yanmars typically used 
>> the
>> Johnson pump.
>>
>> If you have an engine with the JOHNSON PUMP (it says so right on the back
>> plate), you can use the Johnson impeller kit which comes with the oring,
>> some unneeded paper washers and the impeller. Yanmar also sells this
>> impeller, but sells the o-ring separately (and is probably more $$). He
>> recommends just getting the Johnson kit if you have the johnson pump.
>>
>> If you have an engine with the YANMAR PUMP, (may say yanmar, but doesn't 
>> say
>> Johnson :), then you probably have to buy the impeller through Yanmar or
>> some other OEM supplier. It needs the paper washer.
>>
>>
>> RIGGING:
>> ========
>> The riggers discussed how to tune the rig. They indicated that the cap
>> shrouds should be tensioned to no more than 12% breaking strength.
>>
>> They demonstrated proper use of the Pro version of the Loos gauge.
>>
>> They recommend the use of Boshield T9 spray on the turnbuckles to 
>> penetrate,
>> lube and seal out moisture. DON'T use this on turning blocks however
>> because it leaves a waxy buildup behind. Sailkote or other dry lubes are
>> preferred for turning/sliding blocks.
>>
>> They spent a considerable amount of time discussing the concept of 
>> pre-bend
>> in the mast. (my interpretation and words follow here, so correct me if I
>> incorrectly conveyed what they said)
>>
>> Pre-bend is a slight bend in the mast arching aft. Even for a furling 
>> main!
>> The reason is that when the mast is perfectly straight in column, the 
>> middle
>> will tend to pump (wiggle fore and aft) which will cause damaging fatigue
>> stresses on the mast.
>>
>> They indicated that we absolutely want to ensure that our mast has some
>> pre-bend. This is accomplished by ensuring that the FORWARD LOWERS are
>> tensioned properly and tighter than the AFT LOWERS, and that the backstay 
>> is
>> not too loose. This is to pull the middle section of the mast slightly
>> forward and introduce some bend.
>>
>> An interesting side-note: While at the Marina Del Ray regatta a couple
>> years back, I noticed that most of the C320s there had very loose (almost
>> floppy) forward lower stays.
>>
>> An observation on their techniques: If you've seen Brion Toss's video on
>> rig tuning, he has a far superior technique for adjusting the 
>> turn-buckles
>> which puts less stress on the turnbuckle and is easier.
>>
>> Procedurally, they said, put enough tension on the cap stays (highest 
>> one)
>> to keep the mast from falling down. Then generally work from the bottom 
>> up,
>> side to side until the shrouds are up to tension.
>>
>> There was a lot more, but it seemed obvious to me, so I don't recall
>> specifically what they said. Sorry!
>>
>>
>> -Jeff Hare
>>
>>
>