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

[jonvez at comcast.net]

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 
> 
>