[C320-list] exhaust elbow question

[jonvez at comcast.net]

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 <jvanvessem at sbcglobal.net> 

> 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 
> > 
> > 
> > 
> >