muffler crack?

[Ron Hill]

Ken : You need to look at a C34 MK1s factory routing of the exhaust hose. 
Maybe you would have rerouted it differently?

Too bad that Gerry Douglas didn't consult Centek's engineering before designing the C34 muffler.

Out 

[KWKloeber]

Ken : You need to look at a C34 MK1s factory routing of the exhaust hose. 

Ron:

I'm trying to visualize it -- but don't have one to look at.  Why does it need to be high all the way thru the port locker?  It  seems to be a very similar run as mine, which could be dropped down low after the initial rise high under the coming.  Is there something stopping it from being dropped down lower once it hits the high spot? 

ken

[Stu Jackson]

I'm trying to visualize it -- but don't have one to look at.  Why does it need to be high all the way thru the port locker?  It  seems to be a very similar run as mine, which could be dropped down low after the initial rise high under the coming.  Is there something stopping it from being dropped down lower once it hits the high spot? 

I linked to a picture in one of my last posts.  One showed my son in the port locker, another showed the hose routing.

The REASON is that CY put the HOLE at the aft end high up, and then it drops down to the transom exit thru hull.  Those hoses aren't FULL of water at any time anyway.  Not a big deal.

[KWKloeber]

Thanks Stu,

I saw the "end", and the "beginning", just didn't see the "middle" and why the hose couldn't be dropped down.  It's not a big deal w/ the Aqualift with it's over capacity.  But with the comparitively tiny capacity of the 8" roundm, and being a side-inny, half the capacity of a top-inny, IIWMB I'd drill a new hole thru the locker near the aft bottom, drop the hose down at a 45 angle, and assure that the absolute minimum of water is left in the hose at any time. 
"Belt and suspenders," .....or s*it happens .... or, hydrolock, *ouch*
kk

I'm trying to visualize it -- but don't have one to look at.  Why does it need to be high all the way thru the port locker?  It  seems to be a very similar run as mine, which could be dropped down low after the initial rise high under the coming.  Is there something stopping it from being dropped down lower once it hits the high spot? 

I linked to a picture in one of my last posts.  One showed my son in the port loc ker, another shoed the hose routing.

The REASON is that CY put the HOLE at the aft end high up, and then it drops down to the transom exit thru hull.  Those hoses aren't FULL of water at any time anyway.  Not a big deal.

[Ron Hill]

Ken : Unlike a C30, the exhaust of a C34 exists thru the hull, not the transom. 

A thought

[KWKloeber]

Ken : Unlike a C30, the exhaust of a C34 exists thru the hull, not the transom. 

A thought

Thanks for the clarification, Ron.  Yeah I finally realized that from Stu's last pic (blue seawater showing thru  )
That really doesn't affect how it's run thru the sail locker, and making that mod would greatly inhibit any water draining back to the muffler from, as you say, the variable pitch of the boat and what might end up in the "long" horizontal run in the locker.)   At the thru hull, you'd just use an elbow. As I say, just belt and suspenders with a tiny muffler, which seems to be a viable option per Jim's install.

-k

[Noah]

Cockpit locker and aft cabin is different then a C30 too. No sail locker. A big fuel tank in the way. They routed it the only way possible/practical as far as I can see. Don't know why folks would not opt for OEM replacement muffler (for a couple of hundred bucks more) instead of spending a lot of brain damage and labor to trying to re-invent the wheel---one that has worked pretty well as is. 20+ years on a $375 muffler seems like a pretty good value to me.

[KWKloeber]

Noah,

Apologies if I am misunderstanding the locker layout -- I have conflicting descriptions.  From Stu's photos and the description of rhe route. it looked like the hose could drop down (say at a 45 angle) after it hits the high spot right above the entry into the locker?  n'est pas?



For whatever reason (money?) Jim didn't, so it just begged the question is there a way to address Ron's comment about water back flowing to the small 8" muffler (especially it being a side-inny.)  FWIW, the Centek is a MUCH better muffler, quality wise.

ken

Cockpit locker and aft cabin is different then a C30 too. No sail locker. A big fuel tank in the way. They routed it the only way possible/practical as far as I can see. Don't know why folks would not opt for OEM replacement muffler (for a couple of hundred bucks more) instead of spending a lot of brain damage and labor to trying to re-invent the wheel---one that has worked pretty well as is. 20+ years on a $375 muffler seems like a pretty good value to me.

[Stu Jackson]

Noah,

Apologies if I am misunderstanding the locker layout -- I have conflicting descriptions.  From Stu's photos and the description of rhe route. it looked like the hose could drop down (say at a 45 angle) after it hits the high spot right above the entry into the locker?  n'est pas?

OK, now follow that hose more to the left as it exits the picture.  About two feet aft to the left side of the picture is the "end" of the port locker, inside, which consists of a vertical piece of painted plywood with a hole in it.  That hole is as high up as it can be.  The hose goes through that hole.  After the hole and the vertical plywood is the lazarette under the helmsman seat.  The first time the hose has an opportunity to go down is once it gets into the lazarette.

Yes, they could have drilled the hole in the aft end lower, but that would have messed up storage in the port locker.

***********

Re: volume of water in riser and the different mufflers.  I understand the point, Ken, but it would be extremely helpful to share engineering.

IIRC, my raw water intake hose is 1/2" and 5/8" from the rw pump to the HX and then on to the exhaust riser nipple.  Assuming that those hoses are full, the 1 5/8" hose then would be a lot less full of water.  Also, if IIRC, the rw pump could be all of maybe 6 gpm.  So, when the engine shuts down, it appears, prior to even a rigorous engineering analysis, that there simply can't be a whole lot of water in say, 10 feet of that 17 foot exhaust hose.  Then, as you said, compare that to the volume of the muffler. 

My point is that we shouldn't be giving Jim any reasons for concern about his new muffler installation, nor giving him any sleepless nights worrying about having to drop the aft end of his hose in his port locker.

[Ekutney]

Last year just about this time of year I purchased my boat and in the Feb/Mar timeframe started after the to do list.  I replaced the riser, muffler & exhaust hose.  I went with the OEM muffler because like others have the previous one lasted 30 yrs.  The exhaust hose is 17 ft long, it runs from the muffler up into the port cockpit locker (a hole at each end at the outward port side of the locker) then out into the port side of the lazarette then to the transom.  There is a high point loop in the transom to prevent backflow in a following sea.  I ran the exhaust hose from the port cockpit locker; first ran it through the hole going fwd into the head locker then connected to the muffler.  Next ran it through the aft hole in the port cockpit locker into the lazarette then to the thru hull.  I replaced the original thru hull with a stainless steel one to make sure all components were solid.  I can say that of ALL the hoses I replaced on the boat this was the most difficult, although I have not done the pumpout hose YET.  Getting and out of the port cockpit locker is not easy, once inside there is plenty of room to move around but getting in & out takes a bit of flexibility, not easy for a 6 ft 250 lb 60 yr old guy.  It is also difficult working with the wire reinforced exhaust hose, I have rubber coated work gloves that make handling/twisting the hose much easier (they provide a good grip).  I made sure the hose was properly positioned by turning & twisting it into position, this prevented any stress points.  I used tied wraps to fasten it in three places, one inside the head locker near the muffler, one inside the port cockpit locker & one on the transom bulkhead.  I did not have to but it gave me additional confidence that no matter what the hose would not move around.     

[KWKloeber]

Stu

I see what you mean about the RW pump flow volume.  It was centek that had first raised the issue of potential back flow using the lower volume side inlet type with a long hose (no high loop right behind the muffler.)  It seemed logical to me.   I hadn't estimated the possible water volume.  Their other issue was the hose getting filled with the rail buried and the spillover point being distant from the muffler.

Ken

Stu

Noah,

Apologies if I am misunderstanding the locker layout -- I have conflicting descriptions.  From Stu's photos and the description of rhe route. it looked like the hose could drop down (say at a 45 angle) after it hits the high spot right above the entry into the locker?  n'est pas?

OK, now follow that hose more to the left as it exits the picture.  About two feet aft to the left side of the picture is the "end" of the port locker, inside, which consists of a vertical piece of painted plywood with a hole in it.  That hole is as high up as it can be.  The hose goes through that hole.  After the hole and the vertical plywood is the lazarette under the helmsman seat.  The first time the hose has an opportunity to go down is once it gets into the lazarette.

Yes, they could have drilled the hole in the aft end lower, but that would have messed up storage in the port locker.

***********

Re: volume of water in riser and the different mufflers.  I understand the point, Ken, but it would be extremely helpful to share engineering.

IIRC, my raw water intake hose is 1/2" and 5/8" from the rw pump to the HX and then on to the exhaust riser nipple.  Assuming that those hoses are full, the 1 5/8" hose then would be a lot less full of water.  Also, if IIRC, the rw pump could be all of maybe 6 gpm.  So, when the engine shuts down, it appears, prior to even a rigorous engineering analysis, that there simply can't be a whole lot of water in say, 10 feet of that 17 foot exhaust hose.  Then, as you said, compare that to the volume of the muffler. 

My point is that we shouldn't be giving Jim any reasons for concern about his new muffler installation, nor giving him any sleepless nights worrying about having to drop the aft end of his hose in his port locker.

[Ron Hill]

Guys : We surely have beaten this one thread to where you could even say

                                                    it's "thread bare".   

[Capt.Jim]

Hey guys,

Just to let you know that I wasn't ignoring you guys. Just sailing around and then staying onboard doing some other maintenance and organizing the buckets loads of crap around the boat.
You know the new boat deal.
It takes 10-15 minutes each time to locate my flashlight or screwdriver since nothing yet have a dedicated spot... But it is getting there.

So far no backflow from the exhaust...

[Ekutney]

Glad your non OEM setup is working.  I had thought about going the same route but ended up replacing my unit with components from Catalina Direct, exhaust riser & water lift muffler including the exhaust hose (all 17 ft of it).  Did it myself and opted to go that route to keep from doing any modifications, it was straight forward and required no thinking... After all the previous setup lasted 30 years in my case.  Yes, only the riser had been changed over ten years ago according to the PO.  Envy you Jim, sailing this time of year in MD is a frigid experience... 26 deg this AM.