engine exhaust to muffler failure (atomic 4)

[Christian Williams]

Not an expert, but I have a Makita XTS13 (basic Home Depot tool). It takes any hex shank bit. It freed up frozen bolts in my traveler when nothing else would. It is compact, which comes in handy in confined spaces.

I have also found it to drill well, using a drill bit, when reaching at arm's length and unable to apply much pressure.

Makita 18 Volt LXT Lithium-Ion Brushless Cordless Impact Driver (Tool Only)

Makita 18 Volt LXT Lithium-Ion Brushless Cordless Impact Driver (Tool Only) - XDT13Z

www.acmetools.com

 

[steven]

I found a small unused 20v from DeWalt in my look-at-this-stuff-one-day draw.
Must have come bundled with something else I just bought.

But I'm concerned it will round the bolt head or even worse tear the head off the bolt.

There are how-to on the internet on cutting the vertical pipe and then using a hand die to cut new threads. And then just screwing on more pipe. 1 1/4" NPT dies seem to be available. Wonder if it's as easy as it looks.

 

[Dave G.]

I think cutting new threads on 1.5" pipe while it is still in the boat is a no go for sure. They use power machines to cut pipe threads at the bib box stores. I don't think you could get enough leverage in that small area to even consider that option. Does your Dewalt have a clutch adjustment ? If so put it on medium setting and let it "hammer" on the bolts for a bit to break loose the corrosion.

 

[bigd14]

I have had good luck with the impact driver on tough nuts or bolts by actually driving them IN briefly, before backing them out. Extension and wobbler might be needed to get to it. Good luck, this is a tough spot to reach.

I will also vouch for Christian's Makita impact driver. I have had one since 2008 with the original two batteries, and with weekly and sometimes extreme use, it still operates flawlessly. By far my favorite tool.

 

[steven]

Thanks. Got the flange unbolted.

Did not have to resort to impact driver or heat.
Just kept applying PTBaster, Liquid Wrench, and WD40. Over and over for a couple of weeks.
Have no idea which product or combination made a difference, or in fact if anything made a difference.
Just kept trying different stuff.

Came loose with a 9/16 socket. 6 point. 6" deep to get out past the elbow fitting that was blocking swinging room for the ratchet handle. 1/2 drive with 14" handle. ( 3/8" drive ratchet/socket broke)

And a friend who has done this before (on houses and cars).

Now to get the new stuff in. Ordering the mixing unit and flange from Moyer Marine.
Pipe and related from McMaster-Carr.

thanks for advice so far. I'll probably need more before this is through.

--Steve

 

[steven]

I know this sounds like a dumb question, but . . .

any hints on working with black NPT pipe ?
How tight to screw together ? Is hand tight enough, too much, or do I need a pipe wrench(s)?

To get the elbows pointed in the right direction I would expect to over tighten a smidgen and then back off to the desired angle.
Will that work with NPT pipe ? Is there a better technique ?

Related: Should I lubricate the threads ? Will burn off of course, but wondering if it will help when installing.

--Steve

 

[Afrakes]

I know this sounds like a dumb question, but . . .

any hints on working with black NPT pipe ?
How tight to screw together ? Is hand tight enough, too much, or do I need a pipe wrench(s)?

To get the elbows pointed in the right direction I would expect to over tighten a smidgen and then back off to the desired angle.
Will that work with NPT pipe ? Is there a better technique ?

Related: Should I lubricate the threads ? Will burn off of course, but wondering if it will help when installing.

--Steve

Wrenches will be needed. You can coat the threads with anti-seize compound. Alignment of the elbows can be achieved using the method you mentioned but better to not back off too much. Try pre-assembly to get the alignment close and mark the mating sections with a line across the joint to aid in final assembly.

 

[steven]

pic of removed hot leg
the riser nipple is around 10", so elbow center to elbow center is around 12"
The new installation will be elbow to elbow 14" (a little more protection against backflow);
and the mixer will orient vertically instead of angled 30deg as shown in the picture.

Also, note the male-female 90deg adapter connected to the flange.
Made it very difficult to get the wrench on the 9/16 bolt holding the flange to the engine.
Instead I plan to use a short (2") horizontal nipple threaded into the flange and then to a 90deg F-F elbow - which will give some maneuvering room around the flange.

 

[steven]

Al, thanks.
I think I am going to try to take your approach a step further.
Final assemble the entire apparatus on my workbench, and then bolt it to the manifold.

That way if I mess up, I can throw away the cheap pipe and start over.

--Steve

 

[Dave G.]

FWIW I would use a high heat pipe sealant/lubricant on the threads. It will aid in assembly and also seal it at the same time. Something like this..

Amazon.com

 

[steven]

some web sites have suggested Locktight 567.
Is it more or less equivalent ?


https://www.amazon.com/567-Thread-S...octite+567&qid=1633200345&s=industrial&sr=1-3

 

[Dave G.]

I'm sure that would work, it's rated to 300 deg F. The Permatex is rated to 400 deg F. Not sure what the actual exhaust temp is, maybe someone else does ?

 

[Kenneth K]

Some of the high temp RTVs are rated up to 600-700 deg F.

 

[steven]

interesting that it is not easy to find a spec for the manifold exhaust temperature.
Not in any A4 literature that I can find.

Got some stuff from Ace rated to 500F. It was all they had in stock at the local store.
https://www.acehardware.com/departm...-and-cements/plumbers-putty-and-sealers/45282

anyone know what kind of hose goes from the hot leg to the water lift muffle pot ?
A4 manual says 1 1/2 ID but no other info about hose rating.
I'm expecting to re-use the approx 2 ft of existing hose, but I'm thinkin might as well change it - its' been there 10 years.

--Steve

 

[Loren Beach]

anyone know what kind of hose goes from the hot leg to the water lift muffle pot ?
A4 manual says 1 1/2 ID but no other info about hose rating.
I'm expecting to re-use the approx 2 ft of existing hose, but I'm thinkin might as well change it - its' been there 10 years.

Interesting question. I replaced my former and ancient exhaust hose with a new one from a local industrial hose supplier, and it is sold for a lot of applications and is specified as "exhaust hose" !
I suspect that the temp inside stays under 200 degrees, i.e. less than boiling water. Because it carries a mixture of exhaust gases and water from the heat exchanger jacket, and I have heard that pure exhaust gases will burn thru it pretty quick if our raw water pump impeller ever fails.
OK. Still not totally answering the question!