1979 C&C 27 Mk III

[Van_Isle]

Few questions out there for any with similar age boats (especially C&C 27's) with A4's:

1) how long has your dry exhaust lasted?
2) how close to the underside of the cockpit floor does your dry exhaust stack go?
3) any problems with overheating of the dry exhaust portion?
4) what kind of waterlift came with these boats and what have you replaced it with (or have you)?
5) how high is your water bypass and does it have a siphon break?

On the maiden 'delivery voyage' for my new-to-me 27 the dry exhaust overheated the cockpit floor and caused the adjacent plywood backing block on the port cockpit drain to smoke and the plastic cockpit drain fitting to partly melt. No flames, but it was a bit tense there for a bit! ... and not a very pleasent way to start off with the boat.

The loop is right against the underside of the cockpit and the pipe wrap is partly falling off and spliting - no doubt helped by the dry exhaust vibrating against the cockpit floor. The pipe underneath appears to be galvanized and in quite good shape. This boat has a plastic vetus waterlift ... so I'm expecting that some of the exhaust at least was redone in the past - but not by last owner (since 2004) and he kept very good records of everything. The water bypass is a very short / low hose with no siphon break. Boat has always been in salt water.

[msmith10]

1977 c&c

1) how long has your dry exhaust lasted?
I replaced mine after 10 years of ownership and I don't know when it had been replaced before that. It wasn't in bad shape but the exhaust flange was leaking and the whole thing had to be replaced just to fix that.

2) how close to the underside of the cockpit floor does your dry exhaust stack go?
Mine is not closer than 2" at the high point of the dry loop.

3) any problems with overheating of the dry exhaust portion?
The dry portion will be very hot. Wrap it with "fiberglass" (or whatever the stuff is) manifold wrapping tape- see the Moyer catalog. After wrapping it will still be hot but not hot enough to burn you or melt anything near it. I have to think the PO rerouted your system or removed some insulation. Otherwise why didn't he have the same problem you had?

4) what kind of waterlift came with these boats and what have you replaced it with (or have you)?
Stainless steel waterlift-- similar to Moyer catalog. At least 10 years old and no sign of failing yet.

5) how high is your water bypass and does it have a siphon break?
Not sure what you mean by water bypass. If you mean the final water flow from manifold to exhaust, mine goes up about a foot above the engine and it does have a siphon break. It enters the exhaust about 6" below the top of the hot exhaust loop.

[edwardc]

Few questions out there for any with similar age boats (especially C&C 27's) with A4's:

1) how long has your dry exhaust lasted?

My original was recently rebuilt by the PO, but I replaced it within a year because it lacked any riser section whatsoever, and had no siphon break in the water feed. Photo album at

http://www.moyermarine.com/forums/album.php?albumid=73

2) how close to the underside of the cockpit floor does your dry exhaust stack go?

A couple of inches.

3) any problems with overheating of the dry exhaust portion?

I wrapped it with the hi-temp wrap Moyer sells, and painted the wrap with their Hi-Temp paint. No overheating issues so far, but it does get hot!

4) what kind of waterlift came with these boats and what have you replaced it with (or have you)?

Stainless Steel waterlift, similar to Moyer's. OEM with the boat 1977. Built by Cambridge Welded Tank Corp.

5) how high is your water bypass and does it have a siphon break?

I assume by "water bypass" you mean the water feed from the manifold to the exhaust. I brought it up as high as I could, into the area under the cockpit seats, and installed the siphon break there. Again the one that MMI sells.

....The pipe underneath appears to be galvanized and in quite good shape.

Galvanized is a big no-no, because the zinc coating burns off and produces toxic fumes. And once its gone, the pipe starts to rust.

Since yours is in good shape and not rusted, I suspect it's stainless, not galvanized.

And, oh yes, Welcome to the forum!

[sastanley]

VanIsle,

Welcome...I do not have a C&C but my Catalina hot stack is up under the galley. I put it within an inch, and it turned the plywood black.

I also like Ed's solution..wrap in good condition helps, & I guess the hi-temp spray helps too..I have a similar installation.

I got some of that adhesive backed, aluminum padding stuff they put in old cars for firewall insulation underneath my cabinet to dissipate the heat and protect the cabinet a bit..seems to help.

I did the no-no and used galvanized for my hot stack...I'll do black iron next time. It did off-gas for several hours when it was new..we ventilated well during that period.

I also have a Vetus waterlift, and found a leaky stainless canister type in a locker that I assume was original.

Get a siphon break for the water injection..mount it above the waterline.

[David Masury]

1975 C&C 27 MKIII

I have never had the problem with the heat distorting the cockpit floor, I know that the previous owner must of had the dry stack replaced... I have not had the need to touch it (yet) I can certainly offer to take picutres and measurements for you of the entire system.

As far as a waterlift muffler... I replaced the original metal one five years ago with a coast gaurd apperoved fiberglass one rated for 30 HP... nice and complact and does the job.

Can I presume that you have the factory fresh water cooled engine rather than the raw water cooled...

David

[Van_Isle]

Wow ... thanks all for the responses so far.

Here are a couple pictures.

1) the offending dry exhaust - big sections of the wrap missing (I've had it tested and it is NOT asbestos). Looks like galvanized pipe to me.

2) a nice shot of the damage to the adjacent backing for the cockpit drain and partly-melted drain fitting. That pipe is pretty-much right against the bottom of the cockpit.

3) a shot of the water injection point on the 'bypass' as I called it. That's as high as it goes.

I hope to route this whole section to the port locker and gain some clearance and add much additional height for the 'bypass' + add a siphon break. I'll have to relocate the battery charger 1st. Once it is functional again I'll replace the cockpit drain and repair the fiberglass of the cockpit floor.

I'm assuming here I'll use black pipe, not galvanized and I've located a couple local auto-supply places with exhaust pipe wrap.

[Van_Isle]

1975 C&C 27 MKIII

Can I presume that you have the factory fresh water cooled engine rather than the raw water cooled...

Nope - it is RWC. My engine exterior is nicely coated right now with salt deposits from a leak on the head (assuming either a leaking stud or the head is cracked by the alternator / lifting bracket). I had seawater boiling off from around the rear two plugs during the delivery trip. Next project! And this is of course a new occurance - there was no evidence of leakage prior to purchase.

Water pump is leaking nicely too ... so that's probably 3rd on my list ... and it does appear from records (the boat was an estate sale and it came with quite a complete log from 2004) to have been a chronic issue - the pump's been worked on at least 3 times in the last 5 or 6 years.

.... hmm ... I'm sensing a trend here with respect to projects.

I don't believe the PO did any exhaust work on the boat - There's nothing in the maintenance records since 2004 and from looking at the log it appears it was a very rare occurance that the PO ran this engine for longer than 1/2 to 1 hour at a time - so that might explain the lack of any overheating issues.

I do have the opportunity to pick up a 1977 Atomic 4 complete for $200 ... apparently not run for quite a while .... not sure how benefit that would be in terms of parts.

[Mo]

Fyi

Hey Van,

Just looking at those pics the rise IS too close to the cockpit floor. Using black iron is a good option...stay away from the galvanized pipe. Another thing I don't see is a wet injection (from your manifold) on the reward downside of the riser. Attaching a pic to show you what I mean. Did mine about 3 yrs ago now, I put 2 packages of wrap on the pipes as well.

Attaching a diagram of what I did on my boat...works fine.

[msmith10]

The current setup is OK, it's just too close to the cockpit floor. You'll have to drop it and turn it away from that cockpit drain. I would guess that 1" clearance might be enough, 1-1/2" for sure. Not the ideal height of riser but it will have to do.
If I had a chance to pick up a decent parts engine for $200 and had a place to keep it, and didn't have to drive too far to get it, I'd pick it up. Can't make too big a mistake for $200.

[sastanley]

whoa..yup..needs some better engineering

VI..you've obviously identified a mjor problem area...Take a look around the exhaust forum section here at the various designs to give you some ideas..some of them are pretty inventive. We've got to get that hot stack away from the cockpit floor & scupper especially () - If you can 'relocate' the hot stack to an area without stuff right next to it that would be the best option. Some of us have the A-4 in the middle of the boat, with 20'+ of an enhaust run with no problems, so you should be able to afford a little extra distance on the exhaust plumbing & piping to allow it to function better and not burn up other boat parts.

Do you have the ability to widen up the view of that area with some other pictures to help us give you some ideas? The area under the cockpit is always tight and a pain to work in.

A 'parts' engine is always a good option..or sometimes, it turns into the 'project engine' that you rebuild leisurly and maybe install it in the boat someday. It is pretty easy to get them running on a bench at home with a water supply (hose & 5 gallon bucket), couple gauges (oil & temp) & a 12 volt battery.

[Van_Isle]

Thanks guys,

Mo: the wet injection (bypass as I called it) is seen in the 3rd picture.

msmith10: Somewhere on this site is a great picture of a C&C 27 with the exhaust diverted to the port locker. I'll link it when (if) I find it again.

I'll take some additional pictures later today and post them up. For now here is a shot of the port locker (yes that is Halon).

I've still got lots of good fall sailing weather here ... so what I am thinking is in the interim I'll re-wrap the exhaust as-is. Our local auto parts supplier has wrap in multiple widths / lengths available in-stock.

I only have about a 15-minute run in and out of my berth. More time to tinker with the design and order parts for a rebuild in January, when my schedule is a bit less hectic .... I'm thinking. At the worst I'd be no more that an hour motoring from home ... and can monitor temps.

Cockpit drain hoses need replacement anyway so I can do that work now.

The water leak has me a bit more worried - I'll investigate that a bit more this weekend but again both situations can, I believe, be monitored. Again however I'd rather not (as I am sure most agree) end up with the engine opened up for a couple weeks awaiting arrival of parts.

I'll look into that used engine a bit more as well.

[Van_Isle]

Anybody used 'DEI Titanium Wrap' for this application? While the cool 'carbon fibre' look is probably overkill for the Atomic 4, it is currently on-sale at my local auto parts store ... doesn't need to be wetted to wrap .... isn't recommended to be used with any exterior coating (which would be just a plain mess to do in-place) ... and has a significantly higher temperature rating than the same company's standard wrap:

http://www.designengineering.com/category/catalog/dei-cycle/motorcycle-exhaust-pipe-wrap-kits/titanium-exhaust-wrap-lr-technology

[Van_Isle]

Found the C&C 27 picture I was looking for ... in this post:

http://www.moyermarine.com/forums/showpost.php?p=15607&postcount=16

[Van_Isle]

Well I decided to get a local marine mechanic to do up a new dry exhaust for me, since I also have that leaking cylinder head and checking the studs indicated all were tight so the leak was obviously more serious than a weeping stud / stud nut. We've since determined the cylinder head is cracked so I figured might as well have it all done-up at once.

We managed to get the exhaust flange unbolted from the manifold in the boat (surprisingly easy!!) and the mechanic took the whole dry exhaust assembly away with him. I have the exhaust manifold completely off now too.

He figures he can lower the dry exhaust by about an inch without any issues to get some clearance to the underside of the cockpit. He didn't really like the idea of taking the exhaust to the side as there isn't much of a gap between the cockpit drain hose and the bulkhead on the port side. He'll make up a new one with black iron pipe except for the water injection point will be in bronze. He plans to angle it a bit towards the centerline to maximize clearance to the cockpit drain.

He's also going to make up a new wet injection and loop it up as high as possible into the cockpit with an anti-syphon valve. He recommends a Vetus valve.

So things are on the mend!

I must say it's been nice to experience that all the tips, concerns, potential solutions I've garnered from this site met with agreement from the mechanic.

I also got my cockpit drain hose sorted out myself.

[JOHN COOKSON]

He plans to angle it a bit towards the centerline to maximize clearance to the cockpit drain.

Having the hot section near, at, or slightly across the center line of the boat will ensure that it will keep water from entering the exhaust system\engine equally well on both tacks.

TRUE GRIT