[C320-list] exhaust elbow question

[jonvez at comcast.net]

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 
> > > > 
> > > > 
> > > > 
> > > > 
> > 
> > 
> 
> 
>