Popping the cork on a dredge

[GrizzlyGremlin]

Got some big plans ahead of me. I want a 4" but regulations here require no more than 5hp. I cant find a single 4" that can use that little horsepower. I really dont want to settle for a 3" but may have to. I just cant get by the fact that a 4" can do almost 2x the volume as a 3.

Who has a solution for me?
Is there a 5hp motor out there that can run a 4"?

 

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[okbasspro]

Find you a old style L head 5hp Briggs put a p180 pump on it and rock on

 

[Goodyguy]

I run a 5hp Briggs & Stratton on my 4" Keene
Had to remove the air compressor to use all the HP for suction, plus have to run the engine wide open.


It works ok, but also have to baby the feed when in mostly sand to keep from getting plug ups in the hose that more horse power would eliminate.



GG~

 

[tertiaryjim]

Use an infinity style jet. Set up your compressor with a small engine that you can firmly stake or tie off on shore.
I did this with a small keen compressor and a 3 hrs engine. That little engine had enough toque that I adjusted the sheave size so it only ran about 1200 rpm. Could have gotten it lower.
Also, don't use the old crash box style header. The lift required uses more horse power.

 

[bill-costa rica]

get a older briggs 8 hp and take off the 8 hp sticker and replace with a 5 hp. now you have a 4 inch that will work. or stay with the 5 hp and make the 4 inch a sub surface dredge.

bill/cr

 

[Timberdoodle]

The key is the jet like tertiaryjim said. A more efficient jet uses less power and can certainly allow the use of a 4" using less than 5hp. I built a 4" running 10ft of hose using a Honda/keene p90 combo - no air. O/U sluice with jet flare (at the moment) and the whole package is no larger than a Keene 2". (no I'm not dreaming)

The Jet will determine power requirements and throughput volume to the sluicebox so you can also use a smaller sluicebox if your efficiency is good. A infinity/couple type jet can achieve this. I outlined how to build a 2" pvc infinity on GPEX forum. If you have a welder, I can give you some pointers on how to make a steel 4" if this interests you.

 

[munkirinch]

Nitrous?

 

[Timberdoodle]

Nitrous?

No nitrous - lol.

Just a much more efficient jetting system than a log jet. 60gpm at 30psi jet feed promoting 270gpm draw on my multijet. Log jet's run in the area of a 1-1 input to draw ratio which would require close to 270gpm feed for 270gpm draw which also results in a box capable of handling over 500gpm volume. I work mainly smaller streams and rivers where I don't need to have air most of the time and if I do, then I have a 12v system that I can bring in.

 

[russau]

The key is the jet like tertiaryjim said. A more efficient jet uses less power and can certainly allow the use of a 4" using less than 5hp. I built a 4" running 10ft of hose using a Honda/keene p90 combo - no air. O/U sluice with jet flare (at the moment) and the whole package is no larger than a Keene 2". (no I'm not dreaming)

The Jet will determine power requirements and throughput volume to the sluicebox so you can also use a smaller sluicebox if your efficiency is good. A infinity/couple type jet can achieve this. I outlined how to build a 2" pvc infinity on GPEX forum. If you have a welder, I can give you some pointers on how to make a steel 4" if this interests you.

Could you post a link here so we could eyeball your post?

 

[CabarrusGold]

I made a 4" jet using muffler pipe from local muffler shop and bell reducer/pipe from Granger. Had a 5hp Briggs with P-180 on 15' of hose. Worked great. I now have a 5" Gold Grabber that I use. Sometimes I still use the 4" on the 5" rig due to some locations that will not allow 5" dredges. Trick is getting the 4" jet to seal up on 5". I had a 16" wide sluice on the 4". Make sure you get the pressure right on the jet. I think I went down to 1" pipe. The jet hole ID was around 3/4" shaped like a cigar. Good luck.

 

[bill-costa rica]

there is a guy named trev from new Zealand that made a low power subsurface dredge called a suitcase dredge. I never built one , but from what I can tell it worked very well. he still has plans on his yahoo group goldminers. take a look at that. with a 5hp you can get a little suction , but not a lot. people that say a 5 hp dredge works great have never had a dredge that does. with a 5 hp motor and the best pump and jet log you can get will still be only mediocre.

bill/cr

 

[Timberdoodle]

Could you post a link here so we could eyeball your post?

Here's the link Infinity jet for gold dredge

For steel - Yes, Muffler pipe is the way to go for an easy build. Look for a 5-4 sweeping reduction instead of a quick flare which will help. Weld a 1.5 threaded pipe nipple to the side for manifold input. Take a 4od pipe long enough to make it out the front of the jet as the input connection to hose and slide it into the bell until 1/16 dimension is left (you can tab some spots on the pipe or add a weld build up to help set dimension. You could try a 5ply silicon 5-4 reducer and a couple hose clamps on the front end to seal off the front, but you will need tabs or screws to keep the pipe centered. The silicon reducer will allow for easy disassembly and testing until you have it the way you want. You can either weld up the front with a adapter later or just keep using the silicone reducer since cleaning the gap is often required on a ring type jet.

Hope this helps

 

[panningjack]

Agreed. A couple/infinity jet will do the trick. I run a old gold divers infinity jet and a 2" clear water pump on 20 feet of 4" hose. I have almost as much suction as my buddy's Keene 4". My air compressor is ran off of a separate 2hp engine

 

[Jason in Enid]

Got some big plans ahead of me. I want a 4" but regulations here require no more than 5hp. I cant find a single 4" that can use that little horsepower. I really dont want to settle for a 3" but may have to. I just cant get by the fact that a 4" can do almost 2x the volume as a 3.

Who has a solution for me?
Is there a 5hp motor out there that can run a 4"?

Who is measuring HP output? Are you looking at a sticker? 5.5 doesn't mean it puts out 5.5HP. There was a class action lawsuit not long ago because those ratings were always higher than reality. That's why you find displacement ratings now. Just peel the sticker off.

 

[Timberdoodle]

Agreed. A couple/infinity jet will do the trick. I run a old gold divers infinity jet and a 2" clear water pump on 20 feet of 4" hose. I have almost as much suction as my buddy's Keene 4". My air compressor is ran off of a separate 2hp engine

Nice Panningjack!! Gold divers made a nice quality jet!! That's another thing I love about a more efficient jet. Less expense for a pump.

 

[principedeleon]

Nice Panningjack!! Gold divers made a nice quality jet!! That's another thing I love about a more efficient jet. Less expense for a pump.

So do you think timber; that with a 8hp engine and the ke201 pump i can run a 6" dredge with 25' hose using the coupler jet ?

Btw..Is the coupler jet more efficient then the muffler type? Doesnt water enters like at 45degree angle with that kind of setup.

 

[Timberdoodle]

So do you think timber; that with a 8hp engine and the ke201 pump i can run a 6" dredge with 25' hose using the coupler jet ?

Btw..Is the coupler jet more efficient then the muffler type? Doesnt water enters like at 45degree angle with that kind of setup.

I'm not familiar with the older Keene pump spec's. If you are running something with it already (4" or 5") then you should be able to at least double your efficiency with the muffler type easy build. Their are always factors involved which add to the mix which makes it harder to judge until it is built and tested. You will need more feet per second flow in the suction hose to lift 6" material so it's not just water volume increase that can be easily factored. So far I have only built jet's from 1-4" so I would not want to say until I get experience with the larger jet's and time running them in the field.

 

[principedeleon]

Im currently running a 4" with the pump but i would also like having a p90 pump running my 4" as you are doing with your setup can you Show us your 4" jet.. I dont see much pictures of the finish product online just a lot of people speaking on the sucess. Thanks

 

[Timberdoodle]

I'm currently working on construction/part sourcing so I don't have any pretty ones yet, just prototypes. I hope to have something in the next few months for public.

 

[principedeleon]

Just trying to catch up here is this the principle idea of a muffler infinity jet ?