From wet to dry tailpipes
 

I've currently got a set of silent choice lightning headers without the diverters going into jacketed dry tailpipes. Do to the way the system was originally put together, from a previous owner, the connected from header to tail is not water tight, there is a gap that was previously filled with high temp silicone. Because of this Im getting reversion and water in my oil. My plan, and what i am currently in the process of doing, is to weld all the water ports in the header closed, weld a 1/2" stainless fuel bung into the top of the headers waterjacket just after the collector and dump it out the back of the transom. My questions are: is 1/2" going to be a big enough bung/hose to dump the water without building up and excessive amounts of pressure. Also, is the heat coming off the tail jackets now without water going to cause any issues? I've debated opening up 2-3 of the small water port holes to allow a minimal amount of water still to pass through the tailpipes and to help relieve any pressure build up. thoughts?

Your boat is most likely going to catch on fire if you do what you are proposing.

What if I were to only close up half of the water ports? Would that still allow enough water into the tails for cooling and relieve enough of the pressure to get away with using 1/2" bungs/hoses?

Why not just fix the previous owners screw up???

trust me I would love to by putting a new set of headers and matching tails on. But $3-5k isnt in the current budget. The headers seem to pressure test good so it's really a fitment issue between the header and tail. I'm trying to come up with a good proper way to fix that and make a good seal then I wont have to dump any water.

Make 7 more posts and then post a pic of what you have.

I think I've got it figured out. Fortunately there are other people out there more helpful than saying my boat will catch fire and posting sarcastic comments without ever offering any real help at all.

I agree, and I agree with the comment. However if someone says something is broken and asks for advice and someone else response is essentially "fix it" that also is a true statement yet not helpful. I was responding to others comments or questions on this thread, I did not continue to keep it alive alone. So sarcastically saying to keep it going with pictures seems uncalled for and less than helpful. Wouldnt you agree?

okay, that being said and my misunderstanding I apologize sincerely. It seemed sarcastic to me, but I do now understand what he was getting at with the amount of posts it would take to get all the pictures.

Griff I apologize!
I do think my issue stems from the fitment between my headers and tails more so than the amount of water flowing through them. Given that I dont have a choice but to run water, the fitment is what I am going to try to focus on.

I will try to get some pictures tonight.
My headers are supposed to he silent choice, they just dont have the diverter attached anymore. So my water dumps into the tails through 12-15 small holes right at the collector. The tailpipe inside tube slides inside of the header exhaust tube and the water jackets are connected/sealed via a 5" rubber hose that slides overtop both header and tailpipe outer jacket. Without water entering the exhaust right where it does, I fear I would burn up that rubber connection hose. The fitment between header and tail exhaust pipes is my issue, it's very loose and leaves a gap that high temp silicone cannot fill alone and that's where my reversion is getting the water from.

My comment was short and while I can't see.exactly what you are dealing, I can't really see what you need to do to fix it. My comment was directed at the fact you have an exhaust system that was originally designed to work together. The gist of your comment was that the previous owner Mickey moused it to the point it no longer works together. So demickey mouse it. Don't band aid it, figure out why it isn't working as designed and address that. If it's I capable of working as designed something is jacked and rigging something that is jacked my be an acceptable way to get you home safely, it is usually not an effective long term solution

Now

I get

It!

Sorry again Griff. I had to have 10 posts to post any pics.
my own misunderstanding and jump to a negative conclusion was obviously far uncalled for. Pics of my set up to follow

https://cimg8.ibsrv.net/gimg/www.off...ce7391b715.jpg

Head with water jacket outlet holes immediately after the collector

https://cimg1.ibsrv.net/gimg/www.off...670ce037ef.jpg

Jacketed tail
https://cimg0.ibsrv.net/gimg/www.off...5a70a2afb2.jpg

https://cimg2.ibsrv.net/gimg/www.off...d27cc5d103.jpg
https://cimg8.ibsrv.net/gimg/www.off...b80f3e9abc.jpg

The inner tail pipe slides inside the inner header pipe and the watwr jackets are connected/sealed with the hose. There is no clamp, or way to make a tighter fit and the fitment is very sloppy at best. Thats the point of my reversion

My original plan WAS to seal off those outlet holes in my header, weld a bung in the top and dump the water out the transom. Obviously then the fitment of the 2 pieces wouldn't be an issue if there wasnt any water. Finding out how bad of an idea that was, my new plan is to try to fix the fitment.

There is roughly 1/16 - 1/8" gap when you fit the 2 pipes together. My plan is to weld 3-4 beads around the tail and slowly grind those down until they fit snug inside the header. Then before putting them together permanently, filling the valleys created from the weld with high temp silicone. I'm hoping that will create a water tight seal between the two and relieve my reversion issue...
thoughts?

if the slip connection has a lot of slop, you should be able to take the header and tail to a place that does diesel exhaust, they should have dies that will expand/contract the tubing untill you have a nice snug slip fit, or you could seal the water jacket on each side, ad bungs and a 1" diameter jumper hose like cmi's..just throwing ideas out there

I like the idea of expanding the pipe. It's such a small amount it would have to be expanded that I would assume the dies would have to be highly adjustable to the mm. I thought about running a jumper hose farther down the tail, I'm just concerned about the rubber hose that is making the connection between the two jackets. I'm not sure if I put a bung say 10-12" farther down from that, if it would still build up enough heat at that point to melt it.

About how far down the tail should I put the bung from where the hose slides over the jacket? Not having any water pass under that hose, you dont think itll get too hot and melt? The bung in the header would be roughly 6" behind the hose and if I put the tail bung roughly 6-8" down the tail in front of the hose, there will be about a 18-20" space that wont be getting any water right where that hose is. Will that space generate too much heat for hose?

look at this exhaust.... the cooling water goes thru the hose at the joint. the water jacket on the header and the riser is dead headed with the header and the riser being gasketed/band clamped.

If you try and use exhaust hose without water you WILL burn thru it

(pik stolen from 777offshore's ad)


https://cimg1.ibsrv.net/gimg/www.off...62cfc718af.jpg

I would weld up the water holes at the end of the header and at the front of the tail. Then weld in a appropriate marmon flange to the outer pipe. Then weld in a bung on the header and the tail and bypass the water around the joint. I would look similar to the header/tail Phragle posted. Attachment 576428

Its sounds like something other than the rubber hose will need to be used to make that connection. Another question I had with that set up is, the bung in the tail would only be going through the water jacket not through the jacket and exhaust pipe both? If that's the case, I assume the flow will just be natural out the back end of the tail since it wont hit any exhaust until the mufflers.

His.goal is to create a dry joint.

I agree "best" but yes maybe more welding/moding than i want to get into. If wrapping that joint/gap with exhaust wrap will keep that rubber hose from melting right at that water free joint, that might be a good, however ghetto, way to go for the time being.

At some point, possibly next season, I'll be getting new headers. I would like to put a set if thunder and lightning headers on it. My only reservation then would be if I can get those to fit my current tails. I wouldn't have a problem getting new tails as well, but they would have to he 5" as are the holes in my transom currently. Filling and re drilling new holes is beyond what I want to get into and comfortable doing.

well this is my set up
stelling into extension
water runs from header to extension thru a one inch hose and connectorshttps://cimg7.ibsrv.net/gimg/www.off...f3e4f28533.jpg

I think the welding up holes, adding bungs/jumper hoses, exhaust wrap on inner pipe (after fixing fitment) is your only choice with the parts you have now. You'll know soon enough if it won't work. I'd contemplate running it first time sans engine hatch to keep an eye and nose on the connection. Not sure if the high temp silicon (blue) hose would be better in this application.

yea, this setup has been on this boat motors since early 90's ,,as far as i know
never melted any hoses...

flash, is that tail bung dumping the water into a jacket or into the exhaust?