Bad manifold, perhaps?

[Kelly]

standpipe leak

Hi Tom,

I just re-read the thread and was wondering what the final word was? Did you get the standpipe repaired? Where was the failure?

Did the silver lining turn into a full-blown rising sun, complete with heavenly rays and singing?

[TomG]

Kelly,

Thanks for asking! At the moment I'll say it is probably solved, but I reserve the right to change my answer. I need to run the boat a little more to rule out a few other things, but it looks like the culprit was somewhere in the standpipe.

After I called Ken and Don to tell them of my findings and concerns (mid-November), Don really got involved with finding the cause (a throwback to his days as an accident investigator and Air Force fighter pilot, I suppose). I sent the standpipe back to Don for analysis and possible repair in early December. According to Don, the shop disassembled the standpipe and they really couldn't find a "smoking gun" although they supposed the alignment of one plate or another in the innards of the thing could lead to water getting back down the hot section. Moyer Marine sent a new standpipe just before Christmas which I installed just before New Year's Day. I ran the engine for maybe 30 minutes with no water issues. Prior to the new standpipe, the engine would run for 5 or maybe 10 minutes before water would fill the intake and carb and finally kill combustion. I ran the new standpipe for 30 minute or so, and didn't have any water in the carb fuel bowl or the intake, so I felt pretty good about the problem being solved except I never could quite reconcile the onset of the problem... one would think that a new standpipe wouldn't develop this kind of issue.

Now here's the interesting part of the story: About three weeks ago, Don called 'out of the blue' and wanted to know how things had worked out with the new standpipe. I happily told him that the new standpipe seemed to be working flawlessly, but with the cold weather I had only run it for about a half hour. Don patiently spent nearly 45 minutes going over the history of not only this event, but the entire engine. It was really neat to talk with Don for so long... I felt like I was going over my 401k with Warren Buffett or explaining why my PC laptop would lock up with Bill Gates. Don being Don wanted to truly understand how this series of events transpired for a few reasons. The first reason is, I think Don was primarily concerned that I had a different issue altogether and perhaps, given the design and construction of the standpipe, the water was entering via the manifold somewhere. Secondly, if there was a problem with the standpipe, Don really wanted to know how and where.

Unfortunately, the demands of gainful employment (a good problem to have, I suppose), family, and hearth have not allowed me time to run the engine and further test of the manifold since I spoke with Don last. It looks like the stars might align today briefly or tomorrow. I hope to be able to give a full report to Don by Friday.

Finally, I want to acknowledge how truly lucky we all are to have Don and his crew running the show for us Afourians. Don is a gentleman in every sense of the word and is driven by quality. His very personal interest in my problem is testament to this fact. Thanks Don, for Moyer Marine and thanks to Bill for this forum. Without your efforts, our A-4's wouldn't be the well-loved and marvelous machines that they are.

I am hopeful that I can report back by Friday and call this issue resolved.

[olchad]

Water

We have a few indications that water is getting into the exhaust pipe immediately after the manifold, not much but enough to perhaps cause the #1 exhaust valve to stick open. I am wondering about back pressure from the rubber exhaust hose between the standpipe and thru-hull fitting on the T30. If the hose was blocked in some way, a trap would be created that, upon shut down, could cause a "burp" of pressure to push water over the the top of the exhaust stack in the standpipe and back down toward the exhaust manifold. It is unlikely, but i don't want to overlook any possibilities. Any other restriction in the hose could cause the water to back up.
Because the engine is currently out of the boat being re-assembled, I'm unable to do any tests. And with the standpipe out as well, the hose section will probably not tell us much. I will look at it today and see whether the hose is clear and unobstructed.
Tom, have you checked that hose on your boat?
Working on my friend's boat means I have not been living with the problem, so I am trying to reconstruct at this point.

[olchad]

Standpipe

The only aspect of the standpipe that causes me discomfort is its height above the engine. On my Ranger 29 the muffler and the exhaust thru-hull are below the gooseneck coming off the exhaust manifold. It seems to me this is an advantage over the standpipe in the event of restriction downstream. It doesn't guard against complete plug-up, but then the engine probably wouldn't run then in any case.

[Ajax]

Kelly,

<snip>Unfortunately, the demands of gainful employment (a good problem to have, I suppose), family, and hearth have not allowed me time to run the engine and further test of the manifold since I spoke with Don last. It looks like the stars might align today briefly or tomorrow. I hope to be able to give a full report to Don by Friday.
<snip>

I just noticed that you're over on Kent. Is. I hope that I'll see you out there when the weather warms up.

[sastanley]

olchad, if you do not know the age of the rubber exhaust hose, I recommend you replace it. The inner layer can collapse while the outer layer looks just fine...(this can also be true of the radiator hose we use in other sections of the cooling system.)

In my case, I noticed the first winter I had the boat (2008-2009), the wire spring in the middle of my 1977 hose had started rusting and sticking out in sections along the hose, which indicated to me that the exhaust moisture had broken thru the inner layer of hose and it probably failed in some sections.

[TomG]

The only aspect of the standpipe that causes me discomfort is its height above the engine. On my Ranger 29 the muffler and the exhaust thru-hull are below the gooseneck coming off the exhaust manifold. It seems to me this is an advantage over the standpipe in the event of restriction downstream. It doesn't guard against complete plug-up, but then the engine probably wouldn't run then in any case.

olchad,

I see your point, but I think the height of the standpipe is its major advantage. By the time the exhaust leaves the standpipe, it is mixed with cooling water and the discharge is quite tepid. I think the problem with hoses breaking down and collapsing internally are probably very rare after the water is mixed with the hot exhaust and quite common between the hot section and whatever muffler is used (i.e. standpipe or waterlift). The exit for my standpipe is a good 14 inches above the exhaust thru-hull. Once the water gets to the top of the standpipe, 32fps/ps takes over and gravity does the rest. The way my system is designed, a block downstream of the standpipe is low on the list of concerns.

Does your standpipe reside inside the chase in the head just outboard of the mast or is lower in the boat? Mine hangs inside the chase like this:

[TomG]

I just noticed that you're over on Kent. Is. I hope that I'll see you out there when the weather warms up.

Ajax,

Let's plan on in.

One thing I would like to point out is the reason the weather has been so nice on the Chesapeake this winter is because I completely winterized and stripped my boat BUT I left it in the water. You'll know when I've put the sails back on and fired everything up because the weather will immediately turn to crap.

Where are you?

[TomG]

olchad, if you do not know the age of the rubber exhaust hose, I recommend you replace it. The inner layer can collapse while the outer layer looks just fine...(this can also be true of the radiator hose we use in other sections of the cooling system.)

Case in point: when re-doing the exhaust on my boat, here is what the previous owner was working against:


This is a cross section of the hose between the waterlift and the vented loop What a mess. Just one of the many reason I changed to a standpipe (and new hose).