Gasser exhaust questions

[WAC]

Well I continue to go through my new project one step at a time. Over the weekend I pulled the exhaust from both motors back to the mufflers. The exhausts leave the motors at 3" then collect at a 3x3x4 Y that connects to the muffler. My Y's are looking pretty bad with some holes and will be extremely thin after cleaning. I would rather replace but they seem to be discontinued. My searches have come up with only one so far.
Question #1
Does anyone have information on where I can find these? Or does anyone have a couple in good condition they would like to sell?
Can I use the fiberglass collectors? This is before the muffler so I am not sure about heat.

The heat exchangers have 5" rubber end caps with a groove on the inside to fit the divider plate in the exchanger. My searches for this part have also come up empty.
Question #2
Does anyone have part number information or a source for these end caps?
Mine are cracking and I would like to replace before putting any time on them.

Update, I pulled all the tubing from the fittings and the 90's are not correct but rather just cast plumbing 90's. Going to have to replace all the connections. Not sure how hot the exhaust gets and am wondering if I can just use fiberglass fittings as they are rated for 180. I would at least like to use the fiberglass Y collector but again am unsure about heat. Always had outboards so this stuff is new to me and I am trying to avoid a costly mistake.

I am trying to keep the gas motors going for a few years so I can save the money for the upgrade.
Thanks in advance.

[Tony Meola]

Wayne

Of us have converted over to fiberglass so no problems. Have you contacted Merc cruiser for the parts or you might need to change the risers to update the configuration. Updating the risers is probably not a bad idea anyway.

[WAC]

Tony, i did some more research and there should be no issue converting to the fiberglass as it is rated the same as the exhaust hose. I may have to add some support as the cast supported itself. Just money I was hoping not to spend at the moment. I am replacing everything right back to the collector discharge at the top of the motors.
I also found the heat exchanger end caps but they are scary pricey as I am fixing all out of production items.

[Yannis]

Wayne,

When I bought my boat it had no risers.
The water from the exhaust was moving freely from one end to the other, however, in the 28 the situation is rather alarming as the belowdecks are shallow, so the whole exhaust assembly is almost totally horizontal and parallel to sea level, which means that the turbo was getting almost wet - a bad thing especially for Yanmars.
So, I called in my inox guy and made new risers, which he fabricated with wedged pipe sections welded together to make this peculiar S shape.
I think it was like 300 per piece 4 years ago.

[WAC]

Yannis, I have noticed the risers that the guys have on the diesels. I have the original elbow risers coming out of the manifolds. From there they have a significant drop down to below the cockpit floor. When I pulled the exhaust from the front side of the mufflers I got a good rush of water then everything settled down. When standing centerline of the cockpit I get no water entering through the mufflers, when I move to port or starboard I get a flow of water in through the mufflers. So I am just slightly above the waterline with the exhaust, and with the rise up to the exhaust elbows I should be good.
The PO replaced the elbows last year but I plan to pull them for inspection. I ordered all of the new fiberglass 90's and Y's today and with all new exhaust tubing I will be new from the manifolds back. Not an expense I was expecting but it will provide good piece of mind.
With new through hulls, new bilge pumps, new exhaust fittings and tubing, new bilge blowers, new bonding wiring, all new hoses for everything below deck, she should be one happy vessel in a couple months.
Thanks for the input, as I stated prior I have always been an outboard guy and all of these items are new to me so I like to ask before I go forward so I can do it once and right the first time.
Thanks again.

[mike ohlstein]

Consider surge tubes. Another $50 adds a load of protection against hydrolock, bent valves, and a missed season.

http://www.marine-exhaust.com/index.cfm ... roup_Id=16

[WAC]

Thanks Mike, good idea. Trying to think where I can incorporate them as I will be putting the system back in about 2 weeks. Any suggestions?

[mike ohlstein]

Generally, you just run them along the outboard side of the engines. 18 inches is enough. I'll try to get a picture of mine tomorrow.

[mike ohlstein]

These pictures are from the 2004 refit.....

[Yannis]

Mike,

These are Yanmar 240's ?
Are you happy with them?
How many hours have you put on them?
Thanks.

[mike ohlstein]

230's installed 2001 or so.

I have a couple 'o thousand hours so far. The engines are fabulous. Fuel efficient Powerful enough.

[WAC]

Mike, thanks for the pics. I have seen them installed that way but mine are still gassers. Two exhaust banks coming together in a Y prior to the muffler. That is where my question stemmed from. It rises up fairly significantly to each bank so with the split I assume I will be ok. Not sure if they are needed and or how they would be installed in this set-up.
All my new glass fittings and exhaust tubing should be here today. With all new bonding installed over the weekend I should be one or two weekends away from putting back in the new starboard water pump and exhaust system.
If I can figure out how to post pics I will start doing so.