DIY Genturi Shopping List

Just wanted to thank SAJohnson and all the contributors to this thread - I installed my homemade Gen Turi and it works absolutely fantastic. The generator exhaust exits at a high rate of speed well above the RV before dissipating, and there is no longer a diesel odor under the awning. It's also very sturdy, and I fully expect it will last the life of the rig with no issues. Only thing I'm going to do is paint or powdercoat the tube, but otherwise it's done.

Damnation! A 24G with the rear slide doesn't have a ladder!!!!! Love that MacGuyver genturi!

Great job Suburbanrancher!

I'm glad it worked out so well.

Thanks for the photos.

How did you couple the genset exhaust to the 90 degree elbow?

Old Crows said:

Damnation! A 24G with the rear slide doesn't have a ladder!!!!! Love that MacGuyver genturi!

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Only one good option -- trade it in!

sajohnson said:

Great job Suburbanrancher!

I'm glad it worked out so well.

Thanks for the photos.

How did you couple the genset exhaust to the 90 degree elbow?

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I purchased a piece of 90 degree 1 1/4" galvanized conduit from Home Depot for less than $8, cut 8 relief lines in the end (so it would compress) and secured it with two hose clamps. Though it doesn't feel like it's going anywhere, I may weld (or at least JB weld) it together at some point.

Note that I did take about 1" off the stock gen exhaust with a dremel to ensure the exhaust flowed freely and to make the conduit and aluminum pipe line up perfectly.

Suburbanrancher said:

I purchased a piece of 90 degree 1 1/4" galvanized conduit from Home Depot for less than $8, cut 8 relief lines in the end (so it would compress) and secured it with two hose clamps. Though it doesn't feel like it's going anywhere, I may weld (or at least JB weld) it together at some point.

Note that I did take about 1" off the stock gen exhaust with a dremel to ensure the exhaust flowed freely and to make the conduit and aluminum pipe line up perfectly.

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I see you added scissors jacks also. Great minds think alike.

The conduit looks good. I agree it shouldn't go anywhere, but an exhaust clamp would be more secure than the hose clamps.

I’m doing my own DIY version.

But thinking of going with a much smaller diameter tube for my diesel.

Hoping it might be possible due to the aa out of suction and force you experienced.

I guess I could test it with some different sized smaller diameter pvc pipes and try to figure out how to test the back pressure.

Or worst maybe even a shallow taper/funnel on the bottom.

Any thoughts or ideas?

geob said:

I’m doing my own DIY version.

But thinking of going with a much smaller diameter tube for my diesel.

Hoping it might be possible due to the aa out of suction and force you experienced.

I guess I could test it with some different sized smaller diameter pvc pipes and try to figure out how to test the back pressure.

Or worst maybe even a shallow taper/funnel on the bottom.

Any thoughts or ideas?

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I guess my first question is, why go with a smaller tube?

I'm assuming that the Gen-Turi is designed the way it is for a variety of reasons -- although reduction of back pressure may not be one of them (or not a primary one).

It could be that the designer mainly wanted to make it light and keep the pipe relatively cool.

Maybe extending the exhaust pipe all the way to the roofline would work. I recall emailing a guy who did this mod but ended up *sealing* the opening where the exhaust pipe enters the bottom of the larger vertical pipe. I can't recall why. He claimed it worked fine. Of course he was still using a larger vertical pipe, which would reduce backpressure.

IDK what to tell you. You might contact Cummins-Onan, or any small engine mfr, and ask about extending the exhaust. My guess is that it will be hard to get straight info from them. They will probably just say, "Don't do it, it will void the warranty..." but it's worth asking, esp if you can get a tech or engineer on the phone.

Maybe someone who has experience repairing small engines could tell you.

I'm not sure what you mean by:

"Hoping it might be possible due to the aa out of suction and force you experienced."

Could you explain?

Also:

"Or worst maybe even a shallow taper/funnel on the bottom."

An illustration would help.

Please report back if you get any good info about extending the exhaust.

Thanks SA.

I’d like to do a semi-permanent mounted to the ladder on my J.
I am vain and interested in a smaller diameter tube more for cosmetic reasons then anything. Lol

What I meant was that it sounds like you have an impressive amount of flow/draft/pull. So that makes me think the diameter can be reduced some.

What I meant about the funnel/taper... was basically if just the smaller diameter tube wasn’t enough flow/draft/pull and fabing an upside down funnel/flair at the bottom that widenes it a little where the exhaust goes in.

I will do some experimentation when I get a chance.

Thx again!
Geo

geob said:

Thanks SA.

I’d like to do a semi-permanent mounted to the ladder on my J.
I am vain and interested in a smaller diameter tube more for cosmetic reasons then anything. Lol

What I meant was that it sounds like you have an impressive amount of flow/draft/pull. So that makes me think the diameter can be reduced some.

What I meant about the funnel/taper... was basically if just the smaller diameter tube wasn’t enough flow/draft/pull and fabing an upside down funnel/flair at the bottom that widenes it a little where the exhaust goes in.

I will do some experimentation when I get a chance.

Thx again!
Geo

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You don't want a drain culvert attached to your ladder?

The smaller pipe might work. I have to say though, I really like the strong draft and the extra air mixing with the exhaust. It keeps the larger pipe relatively cool, dilutes the exhaust fumes, and helps the exhaust go further up above the roof.

You might want to search and see if someone has done what you are considering.

With a smaller pipe you would have to be very precise with the positioning of the exhaust pipe inside it, because the genset is on rubber mounts and therefore the exhaust pipe moves some. The last thing you want is for the exhaust pipe to be rattling against the inside of the larger pipe.

A better bet might be to consider just extending the exhaust pipe. I have no idea though how far you can go before back pressure becomes an issue. If necessary, you could step up to a slightly larger pipe using an adapter.

There are a couple potential issues with that (regardless of whether the size is stepped up):

1) The pipe will get very hot.

2) It will have to be mounted to allow for vibration.

Quick update:

One of the 1/4-20 galvanized bolts running through the clamp on the ladder that the tube is secured to, broke.

I don't think it was broken for long before we realized it. No harm done.

I replaced it with a grade 5 stainless 1/4-20 bolt and a nyloc nut.