Looking for Exhaust Advice

[hanleyclifford]

Caleb has some really good ideas on this and I would just add that some Kroil or PB Blaster overnight might help. It's important that you realize what a treasure that system is and that it is worth some TLC. The big advantage of that system is that it does not require the engine to use precious exhaust pressure to drive water uphill. In fuel economy and power over long hauls this is a huge consideration. Right now I use a riser and waterlift system on my boat but if I had a chance to have what you have for your engine I would jump on it.

[LastLeg]

Thanks for the feedback, I would really like to salvage this piece, I am thinking that if I have a coupling brazed on the end as stated in this thread.

Then I would have to use two small pipes and a union. I will give this a shot tomorrow morning, on my way to a welder.

[ndutton]

One of the 'vendors' I'm dependent upon for boat projects is my metals guy. When it comes to something like this I get him in the decision loop as early as possible. He tells me what can and cannot be done, the expected strength of each option and approximate cost.

[hanleyclifford]

Thanks for the feedback, I would really like to salvage this piece, I am thinking that if I have a coupling brazed on the end as stated in this thread.

Then I would have to use two small pipes and a union. I will give this a shot tomorrow morning, on my way to a welder.

If that unit were mine the first thing I would do is cut it off flush, carefully. Next I would run a hole saw into the iron and then by small increments increase the size of the hole saws until I could weaken the remaining steel/iron enough to start peeling the threads out. It would be tedious but the reward is enormous even if you have to special order some not- often-used hole saws. The thing is probably 1 1/4" NPT. Even if you have to spend a couple hundred bucks on tools it would be less than a complete new system.

[Kelly]

standpipe

I just wanted to reinforce Hanley's view that you should prioritize saving your original setup. You'll notice that the piece that failed was not of the original design (I assume). The materials used to make your standpipe and mixer will likely outlast the use of the boat where as the black pipe reconstructions necessitate replacement on a regular basis.

Also, the design of the standpipe makes it virtually impossible to get water backing into the engine from the exhaust.

[marthur]

The reciprocating saw should easily cut through the iron pipe. I would do as previously suggested and insert the saw in the hole, slice the pipe in several places. You should be able to bend or break the sections this creates towards the center of the hole. If you are careful, you might not even mark the copper threads.

I have done this before and for me, the important thing is to adopt a zen like patience. If I try to hurry the job I always do something I regret.

[edwardc]

I agree with your input, I am going to piece together my own exhaust. In my prior configuration I noticed that the water hose exiting the manifold joined the exhaust pipe prior to the lift, based on what I see this should join after the lift.

That is because this is a double-walled/jacketed system. The water enters the outer jacket space between the inner and outer walls, and flows down the length of the assembly, pre-cooling the exhaust without yet mixing with it. At the end of the run, there is an internal injection point where the water finally mixes with the exhaust. As Hanley pointed out, this is a much superior system and should be salvaged if at all possible.

[Kelly]

Exhaust schematic

Here is the perfect opportunity to resurrect my fancy "MSpaint" drawing for clarification!

HERE

[romantic comedy]

As suggest, I recommend cutting it off flush. Then make a cut or three, into the pipe. Then collapse it inward. You can use a vise, or clamp, or whatever.

You want to not heat it too much that could cause the copper to unbraze, and leak.

I can see that a welder or machine shop, could braze a coupling right to the pipe. Probably use a brass or bronze fitting.

That exhaust system is the best kind, and you should try to keep it.

[marthur]

Would it be easier to collapse it inward if you could grasp the part sticking out? If so you may not want to cut it off flush.

[Carl-T705]

Last leg, DO NOT cut this off flush. Cut the pipe with a hack saw blade with tape wrapped around half the blade for a handle. A power saw is too difficult to control on this type of job, you want to work slow, checking the cut area several times for signs of rust or copper indicating you have breached the threads I cut about 1/2 the thickness of the iron pipe with the saw in two places ( about 1/3 the circumference apart). Be careful not to let the end of the blade puncture the copper liner Then I put the pipe ( the iron nipple that is sticking out) in a vise and squeeze the cut section, it may take a couple of trials to be sure you've cut deep enough. Once you've removed this cut section , you can squeeze the pipe again and this will allow the remainder to fall out. This piece is worth all of the effort to save it.... I think!!!

[hanleyclifford]

Last leg, DO NOT cut this off flush. Cut the pipe with a hack saw blade with tape wrapped around half the blade for a handle. A power saw is too difficult to control on this type of job, you want to work slow, checking the cut area several times for signs of rust or copper indicating you have breached the threads I cut about 1/2 the thickness of the iron pipe with the saw in two places ( about 1/3 the circumference apart). Be careful not to let the end of the blade puncture the copper liner Then I put the pipe ( the iron nipple that is sticking out) in a vise and squeeze the cut section, it may take a couple of trials to be sure you've cut deep enough. Once you've removed this cut section , you can squeeze the pipe again and this will allow the remainder to fall out. This piece is worth all of the effort to save it.... I think!!!

This is another fine approach to the problem and I have used it, too. It does depend on having enough "meat" left of the extruding iron to clamp tight. It also requires great care with the hack saw. Study the iron carefully before deciding which approach to take.

[hanleyclifford]

Just to expand on Carl's suggestion: often it is possible to cut two lines in the interior of the iron about 3/4" apart and then grasp what is showing with a vice grips. A slight tapping with a small ball peen might peel away the first couple of threads so some PB Blaster can be introduced. Whatever method you select it must be viewed as a "surgical" operation on a valuable patient.

[romantic comedy]

OOPS, Mac, you are right. Leave it sticking out, so you can whack it in.

[LastLeg]

Carl had the right idea and unfortunately I got his message too late. I should not have used the Sawzall at all as it jump and damaged the tip which caused separation between the brass threaded section and the copper jacket, Edwardc understood the inner workings now I understand very well how this awesome manifold works.

To make a long story short, I finally removed the black steal section from the now damaged manifold. Considering the inner threaded pipe was brass and the jacket copper I worked it just like house plumbing. I cleaned the tip with a sander and soldered where the sawzall created separation. Tested it with a garden and ensure it was leak free after a couple of rounds of soldering it was dry, no leaking. I think if it can stand the full pressure of a garden hose at it will have little problem dealing with the A4 pushing water through it. I plan to install today. If it works, I owe everyone on this thread a beer.