RN Thru Hull Exhaust Options

Carrera911

Carrera911

Location
Cumming, Georgia
I was cleaning up my thru hull exhaust pipe before installing it and found a ton of pinholes and pitting hidden under the foam residue. I found the part new online for $155, too much for a piece of pipe with a flange IMO. I also found a 3' section of 2 3/8 OD aluminum intercooler pipe on eBay for $40. The flange is salvageable so it could be welded on the new pipe. While I can Tig aluminum, I don't have the setup and would have to find someone to do it. Ideally, I would just get a used one but I haven't seen any around. One of the cooling tubes is rotted through as well, but that shouldn't be as hard to source.

I'm sure I'm not the first one to come across this. Anyone know where to source a good used pipe or where to get 3' of aluminum pipe for a better price?
Photo Dec 08, 3 41 22 PM.jpg

Photo Dec 08, 3 41 11 PM.jpg
 
vomitspot

vomitspot

Location
mobile alabama
that sucks
not that its any help but years ago there was a guy who made them out of carbon
i picked one up
really nice part
sorry its not fs its in my sn
good luck
jason
 
Jr.

Jr.

Standing Tall
Staff member
Site Supporter
Location
Hot-Lanta
Easy enough to make your own out of carbon. Just wax a piece of 2” PVC , lay out carbon and wet it out, roll the tube
So you have at least 4 layers. Use streach wrap as your compression wrap. Hang so excess epoxy resin flows out.
Allow to cure 24-48 hrs. To release, hold carbon and smack pvc on ground, tube will slip right out.
 
Sanoman

Sanoman

AbouttoKrash
Location
NE Tenn
Jr. said:
Easy enough to make your own out of carbon. Just wax a piece of 2” PVC , lay out carbon and wet it out, roll the tube
So you have at least 4 layers. Use streach wrap as your compression wrap. Hang so excess epoxy resin flows out.
Allow to cure 24-48 hrs. To release, hold carbon and smack pvc on ground, tube will slip right out.
Click to expand...
You make it sound so easy!
 
Carrera911

Carrera911

Location
Cumming, Georgia
Thanks for all the input guys. I’ve read about people using carbon tubes for exhaust but I always wondered about what would happen if the ext. temps got too high, from say a long WOT run if someone has the water injection set too low. A quick search says 300F is about the max for epoxy. As far as that goes, I should be able to just wrap the existing tube with epoxy and biaxial lol. I’m sure carbon itself has a higher burn point than fiberglass but I’d imagine the epoxy would melt before either of them. While that would probably work for some period of time, I’m probably best off sourcing some aluminum pipe.

On a side note, McMaster was the first place I looked. Their pricing is very weird, some things you can get way more than needed for less than just about anywhere. Other things like this pipe and the cooling tubes are about 25% cheaper on eBay and amazon before factoring whatever they charge for shipping.


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Req

Req

Location
SW Tenn
I just got a 4ft x 2.25" OD piece of SS-304 from flowmaster for 50 bucks. I just weighed it and it comes to 1.2lb per ft. I am using it to run a new lower exhaust tube for a wide tray superjet I am working on. I was not even planning on running a flange just 5200 the crap out of it and have it stick out the back a half inch to combat the splooge dripping down the hull.
 
Carrera911

Carrera911

Location
Cumming, Georgia
Req said:
I just got a 4ft x 2.25" OD piece of SS-304 from flowmaster for 50 bucks. I just weighed it and it comes to 1.2lb per ft. I am using it to run a new lower exhaust tube for a wide tray superjet I am working on. I was not even planning on running a flange just 5200 the crap out of it and have it stick out the back a half inch to combat the splooge dripping down the hull.
Click to expand...
I thought about stainless exhaust pipe being a cheap option but I wouldn't want to run without a flange of some kind. So then I'd need to fab up a stainless flange and get some argon to Tig it to the pipe. I would go this route for sure if I ran in salt since this pipe rotted out from mostly freshwater soaked foam.
 
Req

Req

Location
SW Tenn
I am pretty sure some AM hulls run without flanges but if you wanted a bit of security a few tabs on the engine firewall side of the tube may be enough, and a lot easier to fab up than a full circumference flange on the rear of the ski. Now that we are talking about it I think that is what I will do.
 
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Carrera911

Carrera911

Location
Cumming, Georgia
My reason for the flange wasn't really for security. The factory cutout is too large and would leave a 1/8 to 1/4" gap around the pipe. I also feel like it would be only a matter of time before I sliced my leg on it sticking out the back of the hull. Making a flange would be easy, just trace the old one onto some card stock for a template and cut it out with a plasma cutter or angle grinder. Then clean it up with a flap disc and drill the necessary holes. The only hard part would be cutting the pipe at the correct angle in combination with clocking it since the transom itself is angled. Maybe a 3 hour project all said and done. That is exactly what I would do but sourcing anything other than plain old steel is hard to do in my neck of the woods.
 
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