[C320-list] FW: Re: Tach Accuracy

Sat Oct 7 06:43:51 PDT 2006

At my survey last September (2006), my tach (engine gauge) read 50rpm higher than what was measured using the phototach, at 3000rpm. So you are correct that each one may be different!!

Perhaps we should consider getting a phototach for the C320IA toolbox, so the members might borrow it and recalibrate from time to time.

Karl Mielenhausen

2000 C320 Hull#690 "Silver Lining"

New Bern, NC

http://members.cox.net/mielen/

From: Len [mailto: aqua5len at gmail.com]

To: Allan.Field at comcast.net, c320-list at catalina320.com

Date: Fri, 6 Oct 2006 17:43:07 -0700

Subject: Re: [C320-list] exhaust elbow question

Checked the tachometer on my 3YM30 with a photo tachometer (put reflective tape on flywheel, infrared beam reads actual rpms) and at dock in neutral found boat tach @ 2,500 rpms actually 2,775 rpms, full throttle boat tach @ 3,450 actually 3,775. Each tach may vary, but suggest worth checking. Plan to recalibrate tach to be closer to reality soon. Len Krane Aqua5 #1070 Marina del Rey, CA On 10/6/06, Allan Field <Allan.Field at comcast.net> wrote: > > While at the Annapolis Boat Show today, I talked with the Mack Boring rep > regarding the Yanmar diesels. Here is what he said. > > Warm-up in neutral at idle speed of 900-1000 rpm. We should be able to > hit > hull speed between 2700 and 3100 rpm and we should be able to reach > 3500-3600 rpm's. But he acknowledged that many of us have problems doing > so > due to, "screwing around with different prop configurations". The engine > is > designed for 
continuous operation at three-quarters of maximum rpm's (3600 > x > .75 = 2700). He also said that the engine mounted tachometer will read > about 150 rpm's less than actual. > > When shutting down, put it in neutral, let it idle for 3-5 minutes, then > shut down. If the engine has been run for a long time at low speeds, > after > the 3-5 minute cool down period, rev it up in neutral 2-3 times then shut > it > down. > > Based on something I was told long ago, I make sure that every time I take > the boat out, I run at 3000 rpm's for at least 10 minutes. > > The rep also gave me a brochure for their 1 day classroom followed by > 2-day > hands-on classes. This has been on my Good Intentions List for sometime > now... > > Hope this helps... > > Allan S. Field > Sea Shadow - #808 > Columbia, MD > > -----Original Message----- > From: c320-list-bounces at catalina320.com > 
[mailto:c320-list-bounces at catalina320.com] On Behalf Of jonvez at comcast.net > Sent: Friday, October 06, 2006 8:32 AM > To: C320-List > Subject: Re: [C320-list] exhaust elbow question > > Bruce, > > I agree and will change my SOP. One has to balance logic against all of > the > 'experts' out there--another testament to this list as it's great to > bounce > these things off everyone and get a sanity check. > > Regards, > > Jon > > -------------- Original message -------------- > From: "Bruce Heyman" <BruceHeyman at cox.net> > > > Jeff/Jon, > > If you only put 50-100 hours on your engine per year then you have at > least > > 40 years before you have to worry about it. If however you are blessed > with > > year round access to the water but cursed by the typical wind forecast > of > > "....light and variable, less than 10 knots...." which translates to 2,3 > or > > 4 knots at best and almost 
guaranteed to be on the nose you will put on > may > > more hours. > > > > The typical 18 wheeler seems to get 1m miles or more before the engine > is > > torn down or replaced. I'm guessing that they are only driving on the > road > > > for 2-3000 hours per year but they generally leave the engine idling > even > > when they are eating, sleeping, fueling, loading, being weighted.... so > they > > probably end up with 5-6000 hours per year. At a million miles that > means > > that they rebuild/replace after about 7 years or 42,000 hours. > > > > Wouldn't it be great if we could get 42k hours out of your little > diesels! > > > Now that our boats are made out of what Hershoft called "frozen snot" > the > > boats last forever, provided they are reasonably maintained and > upgraded. > > Which means that boats that are 30-40 years old are very serviceable and > > very popular and usually are priced in the 
20-30k range? Not fun when > you > > have to spend 8-15k to re-power, you will never get that money back! > > > > While I could be wrong I don't think I agree with it is ok to rev the > engine > > when it is cold, even when it is during warm weather. Our engines are > made > > > with all sorts of alloy's which have different temperature coefficients > of > > > expansion. The designers take these into account when they design and > > manufacture the engines. This means that when the engine is cold you do > not > > have the right tolerance in the bearings, gears, rings, valve stems, > push > > rods.... This means then when our high compression engines fire all this > > "slop" results in additional noise, vibration and it would seem to me > wear. > > > > When we start our engine we seem to go through two transitions. The > first > > is very quickly after starting, the low oil alarm goes off and the > 
really > > loud pinging becomes just loud pining. I assume this is most of the > parts, > > > lifters, bearings, rings.... are getting a dose of oil. The second > > transition is after 3 to 10 minutes and seems rather abrupt. I assume > the > > combustion chamber is now up to temperature and the fuel is being burnt > > evenly, the engine just seems to settle down and run smother and > quieter. > > > > I think I'm going to continue to be gentle (no throttle) with the engine > at > > start but based on this discussion I am going to rev the engine at the > end > > > of the day before it is put away for the last time. What do people > > recommend, let it run up to 4000 RPM and then pull the kill or run it up > to > > 4000 RPM then throttle back and kill it when it is back to 900? > > > > Bruce > > Somerset 671 SoCal > > > > -----Original Message----- > > From: c320-list-bounces at catalina320.com > > 
[mailto:c320-list-bounces at catalina320.com] On Behalf Of > jonvez at comcast.net > > > Sent: Wednesday, October 04, 2006 9:58 AM > > To: catalina at thehares.com; C320-List > > Subject: Re: [C320-list] exhaust elbow question > > > > Jeff, > > > > I think you have the right perspective...The same mechanic/trainer also > > said, anything you do to these engines may be a matter of whether you > > rebuild it after 4000 hours or 10,000 hours-- at 50-100 hours a year, > either > > way, it's a loooong time and a lot of abuse..... > > > > Regards, > > > > Jon Vez > > > > -------------- Original message -------------- > > From: "Jeffrey Hare" > > > > > Hi Guys, > > > > > > Don't sweat the warmup/revving thing. Most agree you shouldn't load it > > > until it's warmed up, but reving a diesel after starting it in the > summer > > is > > > simply a non-issue. In the middle of winter is a different story > 
because > > > > the oil doesn't flow well. > > > > > > Revving a *Gas* engine that hasn't warmed up for a couple minutes in > cool > > or > > > cold weather is a different story. Gasoline washes the oil off the > > cylinder > > > walls, while diesel doesn't really suffer from that phenomenon given > that > > > Diesel fuel *is* oil. > > > > > > Clean oil, clean air, and clean fuel, running it hard/fast it'll > outlive > > > > many of us. > > > > > > -JeffH > > > > > > > > > > > > -----Original Message----- > > > From: jonvez at comcast.net [mailto:jonvez at comcast.net] > > > Sent: Wednesday, October 04, 2006 10:52 AM > > > To: John Van Vessem; C320-List > > > Subject: Re: [C320-list] exhaust elbow question > > > > > > John, > > > > > > I am certainly not an expert on this, but the info. I received was > from > a > > > two day diesel class I took that was put on by Mack Boring....I 
guess > I'm > > > back to being confused?? > > > > > > Regards, > > > > > > Jon Vez > > > > > > -------------- Original message -------------- > > > From: John Van Vessem > > > > > > > Running a cold engine up to full RPM is probably the worse thing you > can > > > > > do to > > > > any engine. The Yanmar manual says that you should run the engine up > to > > > full > > > > throtle prior to shutting down, when the exhaust is hot and all > bearings > > > > > are at > > > > their disign tolerance. > > > > > > > > John Van Vessem > > > > Sojourn 645 > > > > Vallejo Yacht Club > > > > > > > > > > > > > > > > ----- Original Message ---- > > > > From: jonvez at comcast.net > > > > To: Allan.Field at comcast.net; C320-List > > > > Sent: Wednesday, October 4, 2006 5:02:18 AM > > > > Subject: Re: [C320-list] exhaust elbow question > > > > > > > > > > > > Koen, > > > > > > > > 
I posted several questions related to the exhaust elbow as I was > > > interested in > > > > proactively replacing mine (my boat is in it's 8th season in salt > > water). > > > > > > > > My confusion was whether the elbow was custom made by Catalina like > the > > > muffler, > > > > or whether I could get it from a Yanmar dealer--than answer is BOTH. > > Some > > > hulls > > > > (with the Yanmar) had a custom elbow made by Catalina...even though > I > > > suspected > > > > this was the case on mine, I couldn't confirm until I went to a > local > > > Yanmar > > > > distributor myself. Even Catalina couldn't answer this > question....The > > > > good news > > > > is that if you do have a custom elbow from Catalina, you can indeed > > > replace with > > > > a stock Yanmar elbow...The bad news is, you need to buy 3 pieces > (for > > > about $360 > > > > vs about $160 for just the elbow). The Catalina 
elbow is a one piece > > > elbow, > > > > whereas the stock parts have a manifold, an adjusting screw > connector > > and > > > the > > > > elbow. Once you have replaced with the stock parts, you will only > have > > > to > > > > replace the elbow (top part) going forward.... > > > > > > > > As for time, Mr. Douglas had suggested 5-8 seasons is a good time to > > > replace. > > > > One suggestion on keeping the buildup under control from Mack Boring > is > > to > > > start > > > > the engine at full throttle and bring it back to idle as soon as the > > > engine > > > > starts...This will blow a lot of the build up out and presumably > delay > > > the > > > > > > > inevitable... > > > > > > > > Regards, > > > > > > > > Jon Vez > > > > > > > > -------------- Original message -------------- > > > > From: "Allan Field" > > > > > > > > > Koen - There are 2 concerns with the 
exhaust elbow. The first is > that > > it > > > > > > > > clogs over time and will impact engine performance. The second is > that > > > > > it > > > > > eventually gets pinhole leaks. Both happened on my previous boat. > > Trust > > > me > > > > > when I say that you don't even want to think about the mess you > will > > > > have if > > > > > the elbow gets a pinhole leak. The engine compartment fills with > black > > > > > soot > > > > > that never completely goes away no matter how much you clean, > clean, > > > > clean, > > > > > and clean some more. > > > > > > > > > > I intend to replace my elbow prophylactically over the winter at > about > > > > > 500 > > > > > hours, change the hose to the aqua lift muffler, add a hump hose > at > > the > > > > > muffler, and pull the muffler, send it back to Catalina, and have > a > > > > > duplicate muffler made to sit on a shelf 
until when I need it. > Again, > > > you > > > > > don't even want to think about the mess if these parts fail. > > > > > > > > > > Allan S. Field > > > > > Sea Shadow - #808 > > > > > Columbia, MD > > > > > > > > > > -----Original Message----- > > > > > From: c320-list-bounces at catalina320.com > > > > > [mailto:c320-list-bounces at catalina320.com] On Behalf Of Koen > > Bennebroek > > > > > Sent: Tuesday, October 03, 2006 9:05 PM > > > > > To: c320-list at catalina320.com > > > > > Subject: [C320-list] exhaust elbow question > > > > > > > > > > I seem to remember someone mentioning that the exhaust elbows on > > C320's > > > get > > > > > clogged and are recommended to be replaced every so often.. > > > > > My local mechanic, who will do the very first service on our boat > soon > > > > > (so > > > > > we do not have experience either with him or with the engine > > > > > service in general), recommends 
we order the elbow and gasket from > > > Perkins > > > > > (I believe tadiesel sells them?) in advance to save time. > > > > > > > > > > Is this a good suggestion? We have purchased the boat used 2 > seasons > > > > ago, so > > > > > I have no idea what the history of this part is. > > > > > > > > > > Thanks for any suggestions, > > > > > > > > > > -Koen > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >

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