[C320-list] exhaust elbow question

[jonvez at comcast.net]

Stan,

I suspect that none of us in the class, especially me, knew enough to challenge this suggestion--It came up when discussing this very topic--how diesels in recreational sailing vessels don't get the work they need, which leads to excessive carbon buildup, which leads to exchanger/exhaust elbow problems--I still have contact info. (I took the class several years ago) and might try and follow up just for the heck of it--Thanks Stan...

Regards,

Jon Vez

-------------- Original message -------------- 
From: "Stanley Rogacevicz" <SROGACEV at holycross.edu> 

> Jon, 
> I wonder if Mack's statement was taken a bit out of context or if it 
> was a quick answer 'shot from the hip' to a question in the class ? 
> Maybe he meant periodically or something ? I know ... big mouth that I 
> am .... I would have had to raise my hand to say something like - That 
> goes against everything I have ever heard about internal combustion 
> engines over the last 40 years - Explain Please. My assumption would be 
> that the best time to blow out the carbon dust is while its cold and not 
> so sticky, but that seems to be a very extreme measure. I know I have 
> read articles that basically said that the first 10 seconds of an 
> engines day is when all the Wear/Damage occurs.... the rest of the day 
> is just a well lubricated coast in comparison. While Jeff's comment 
> about the difference between Gas and Diesel not washing the lubrication 
> off the cylinder walls is fine that's just a small portion of the engine 
> parts that need pressurized lubrication to stay alive. The thought of a 
> relatively dry rod bearing starting at full throttle gives me shivers. 
> Stan 
> formerly "Christy Leigh" 
> c320 #656 
> Wickford/Narragansett Bay RI 
> 
> >>> 10/6/2006 9:32 AM >>> 
> 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" 
> 
> > 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 
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > 
> > > 
> > 
> > 
> > 
>