Any reason to wrap mixing elbow ...
- Thread starter Scott T-Bird
- Start date
to cover insulation of the pipe is my guess. reducing the heat in the engine room.
is there a prize with this quiz?
is there a prize with this quiz?
If the pipe and ell are not water cooled, then the wrap would help with engine room temperature.. If the run of pipe between the engine and the water injection point is long (and this one looks like it may be) it would reduce engine box temps a little..
EDIT: I find it strange to see the exchanger sea water outlet hose going away forward and port.. Must be a vented loop on the other side of the bulkhead?? The injection nipple into the elbow is not visible but it looks to be on the forward side of the elbow, covered and out of sight from this angle..??
EDIT: I find it strange to see the exchanger sea water outlet hose going away forward and port.. Must be a vented loop on the other side of the bulkhead?? The injection nipple into the elbow is not visible but it looks to be on the forward side of the elbow, covered and out of sight from this angle..??
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Mine runs cold at WOT ! ! !
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Just what did I win for all this effort of replying ?
Did I win ? Did I win ? I want to win ! ! !
Just what did I win for all this effort of replying ?
The water injection should be on the downhill side of the 180° elbow which will cool the exhaust gases before they hit the hose and helps to prevent water backing up into the cylinders. For this reason the elbow will get incredibly hot, roughly exhaust temp hot. Beneath the aluminum foil is an insulating wrap. If you are lucky the wrap is fiberglass, if not it is asbestos. The foil helps to protect the underlying wrap and keeps fiber bits from floating freely around the cabin.
If you peel a little away you will be able to see what the insulating material is, yellow/golden its fiberglass, grayish its asbestos.
If you peel a little away you will be able to see what the insulating material is, yellow/golden its fiberglass, grayish its asbestos.
The elbow is "kind of" jacketed with cool sea water from the heat exchanger so if the water flow is sufficient, the whole elbow remains cool through conductivity. There is some warmth on the bottom portion of the elbow.
If your C320 is similar to my C310, the bulkhead aft of the engine practically touches the mixing elbow, which, of course, gets very hot during engine operation. In many C310's with the M25xpb Universal engine, the bulkhead has been charred by the elbow, including my C310. Normally, there is a layer of fiberglass insulation under the foil, with some "chicken wire" under the fiberglass to hold everything away from the elbow.
Here is a view from the front. I've removed the bulkhead that pretty much bridges over the center of the engine for easy access while working on this. The sea water injection is on the outlet side of the elbow. I wondered why the green-striped hose disappears into the compartment on the side before re-appearing at the elbow - the ventilated loop has to be the reason and I hadn't thought of that! I thought it must be going somewhere to heat something up, but it didn't make sense because the other pair of hoses on the closed circuit go to the water heater.
Here's the front view.
I figured that the foil was primarily to mitigate heat but I hadn't thought there would be insulation underneath it. The 2YM15 that I had on Thunderbird wasn't insulated like this, so that made me wonder. There is a MC-614 external regulator mounted on the wall surface pretty close to the mixing elbow. Maine Sail says it is a bad location for this equipment because of the heat. I will probably want to re-locate it. The engine box is pretty tight and it is in 2 parts. The front box is under the companionway stair. The rear box is in the aft berth.
Here's the front view.
I figured that the foil was primarily to mitigate heat but I hadn't thought there would be insulation underneath it. The 2YM15 that I had on Thunderbird wasn't insulated like this, so that made me wonder. There is a MC-614 external regulator mounted on the wall surface pretty close to the mixing elbow. Maine Sail says it is a bad location for this equipment because of the heat. I will probably want to re-locate it. The engine box is pretty tight and it is in 2 parts. The front box is under the companionway stair. The rear box is in the aft berth.
You seem to have pretty good 3 sided access. Of course the oil filter is on the side with more limited access.
There seems to be an awful lot of belt dust, or there used to be a lot. When you relocate the MC-614 it might be a good idea to check its settings and lower the belt manager setting. MaineSail has a good article on doing this and since you will be removing the regulator anyway, taking it home and hooking it up to a 12v power supply makes it very easy. Just tell Sue the new 12v power supply was an essential tool. It will also allow you to play with your MFD at home over the winter. That story worked well with my Susan.
That layout looks like a dream to work on as compared to my setup in a Nike shoe box:
I'm surprised by the number of responses that indicate that the mixing elbow on the smaller Yanmars runs hot. It should run cool. I have always used that as an indicator of flow restriction in the sea water circuit and most of the time it's the elbow clogging.
Good picture, Scott.. So, from the exhaust outlet all the way to where the injection point is will be very hot, exhaust gas temperature ish.. That elbow looks to be kinda custom made(probably by Catalina so that the system works in their engine box) and not the typical Yanmar one since the injection point is on the "downhill" side, meaning that the elbow is probably not water jacketed.. The insulation is definitely to reduce the heat that would be radiating (and convecting) from the exhaust outlet all the way to the injection point. The wrap probably needs to stay to keep stuff in the box from overheating. ..
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Now that you mention it, that doesn't look like a Yanmar mixing elbow and no, I'd very much doubt it's water jacketed. If made from pipe fittings, it's only a fraction of the cost but when it starts to leak, OUCH
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Mine does this and it’s for the loop. Mine is vented to a through hole in the stern. It’s a tell-tale that the pump is working. It’s a real piece of mind.
On my last boat with a Volvo MD7A the exhaust riser was made from off the shelf parts and pieces. When it finally broke (a long story in itself) I was able to create a temporary riser after a couple of trips to the big box HW store. Later I replicated the original.Now that you mention it, that doesn't look like a Yanmar mixing elbow and no, I'd very much doubt it's water jacketed. If made from pipe fittings, it's only a fraction of the cost but when it starts to leak, OUCH
McMaster-Carr sells a black iron 180° elbow a part that is hard to locally source.
Wow, that's a lot of space to work on that engine!
Doubt if Catalina would be wrapping the exhaust elbow with asbestos, in a late model boat. With the hazardous nature of asbestos well documented, they wouldn't want their factory workers nor boat owners to be exposed to the stuff. That would be a huge liability for Catalina. Now if some boatyard decided to wrap it, who knows what it is.
Given the age of the boat, I would agree. But ya never know what thoughts have gone through a PO's mind.
If the tape needs to be replaced, it is muffler insulating tape, can be found at any auto parts store usually in the "high performance" section.