Home made Gen-Turi

smlranger · 01-11-2007, 06:08 AM

OK, weather is cold so got the itch to 'make' something for the motorhome. Reading some threads elsewhere and see several folks have made their own generator exhaust vent pipe. Some are using 3" PVC or CPVC...wow

, 3" is huge and heavy. I'd like to get by with a 2" diameter stack.

I plan on using an EMT elbow on the exhaust tip but the stainless tip is so big (it's welded on), it would take a 2" EMT elbow to cover it, requiring 3" pipe to get the 'venturi' effect. The exhaust on the genset is actually 1 1/4" and I have discovered that a 1" EMT elbow wedges nicely inside the exhaust pipe. This should allow use of a 2" pipe for a stack.

Anyone else done this or something similar? Also wondering if the 1" elbow will restrict the exhaust enough to be a problem?

smlranger · 01-11-2007, 06:08 AM

OK, weather is cold so got the itch to 'make' something for the motorhome. Reading some threads elsewhere and see several folks have made their own generator exhaust vent pipe. Some are using 3" PVC or CPVC...wow

, 3" is huge and heavy. I'd like to get by with a 2" diameter stack.

I plan on using an EMT elbow on the exhaust tip but the stainless tip is so big (it's welded on), it would take a 2" EMT elbow to cover it, requiring 3" pipe to get the 'venturi' effect. The exhaust on the genset is actually 1 1/4" and I have discovered that a 1" EMT elbow wedges nicely inside the exhaust pipe. This should allow use of a 2" pipe for a stack.

Anyone else done this or something similar? Also wondering if the 1" elbow will restrict the exhaust enough to be a problem?

Y-Guy · 01-11-2007, 07:26 AM

I made one for my Raptor Toy Hauler, plan to move it over for use on our Winnebago now. Some of the best info I found was on the barthmobile.com site.

From all I read sticking with the larger pipe is best, make sure you have a gap too. I had no issues with mine, in fact it worked amazingly well.

Here is my write up on the one I made for my Raptor, along with links to some other helpful pages and some photos.

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Well after having the C0 detector sound off last year on my Raptor, the dealer resealed generator compartment and extended the tailpipe a few inches. But we had it go off on us again. So I figured it was time to get one of the Gen-turi stacks. I wasn't about to spend $130 on a new one. So of course the net had the solution. Help from this thread and this thread on barthmobile.com gave me great directions. Set off to Lowes to pick up the parts. Might not look like a factory built unit but at about 1/10th the price it works for me. I plan on painting the steel bars and making a few cosmetic changes, but for now it works. Best of all after running the generator during the trip we had no more C0 issues. With the garage I'm able to just load the whole thing, full length, in the back.

I will be making a change so I can fit it in our compartment on the Winnebago, but plan to keep it around just in case.

smlranger · 01-11-2007, 08:11 AM

Steve:

If I use 1" EMT to connect to existing exhaust pipe and 2" CPVC for the 'stack,' that would give me a 1/2" gap around the EMT which should be enough to entrain air at the bottom.

Is your stack 3" PVC? Hard to tell from the photo. Also, what diameter is the EMT elbow coming out of exhaust pipe?

Y-Guy · 01-11-2007, 02:21 PM

I didn't use PVC I used 3" thin wall PVC sewer pipe. At Lowe's it was in the same area. As a white outside and black inside, its thin and a bit pliable but it won't bend or melt.

The conduit coming out on my Raptor was 1-1/4" so I used 1-1/4" electrical EMT elbow and EMT coupler. Went together really well.

I pretty much took the list from what Bill G on barthmobile wrote and headed off to lowes. Measure your exhaust vent to make sure its the same size.

In the design that I followed the EMT pipe never enters the PVC pipe, there is about a 2" gap, the hot fumes continue to rise up, but there isn't any real back pressure - which you want to avoid as its not healthy for the generator.

This is how mine looks pretty much, but Bill G did a nice job painting his and smoothing the rough edges.

Gary the Wombat · 01-11-2007, 02:42 PM

Nice job Y-guy! What type of strapping is that between the suction cups and the stack? I know from reading the bartmobile stuff that eliminating vibration at that point seemed to be an issue.

Easyrider · 01-11-2007, 02:55 PM

Great job Y-guy! Looks very nice, I like the white finish as it would blend in with the sides of my mh easily. I may have to do some "winter construction projects" too! I'll assume a simple union or two would allow you to shorten the stack for storage. Thanks for the idea of a inexpensive exhaust extension.

Y-Guy · 01-11-2007, 03:30 PM

Thanks. It worked out well for us on the Raptor, no more warnings going off on us. The new Sightseer vents out the back so I am hopefully that I won't need it except when in a more crowded area.

Gary - I think its just a 1/2" x 1/8" bar stock as the other site suggested, though I didn't use 8' - the section that is held on by the suction cups never vibrated much on my setup - maybe it was my amateur metal bending process that solved that issue.