Engine and pump question

Flatline

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Aug 31, 2021
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So the engine i have now is a 6hp honda, it runs a keene p180 and does a great job at running it.. BUT i feel it uses too much fuel, especially for the amount of gold i get back 😭
😆
So my question is what would happen if i would get a bigger hp engine say a 12hp or even bigger and then make the shaft smaller i guess so the pump still fits on it, or get a diesel which i guess should be even more efficient? I'm also thinking about modifying the engine with a better air filter etc etc, but i have no idea what mods would be overkill and not really do much.

Any ideas or suggestions?
 

pepperj

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So the engine i have now is a 6hp honda, it runs a keene p180 and does a great job at running it.. BUT i feel it uses too much fuel, especially for the amount of gold i get back 😭
😆
So my question is what would happen if i would get a bigger hp engine say a 12hp or even bigger and then make the shaft smaller i guess so the pump still fits on it, or get a diesel which i guess should be even more efficient? I'm also thinking about modifying the engine with a better air filter etc etc, but i have no idea what mods would be overkill and not really do much.

Any ideas or suggestions?
Screen Shot 2023-11-23 at 8.53.30 AM.png
 

pepperj

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Smaller the engine less fuel consumption
GX 160/5.5HP uses .37 GPH
GX390/12HP uses .92 GPH
Understanding bigger isn't better always unless the 5.5 is working hard or at a higher rpm then option is lesson the load on the engine or to upside.
Diesel might be a option then run a bio-fuel mixture to cut the cost. Old engines will run on lots of alternative fuels.

 

OP
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Flatline

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Aug 31, 2021
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Smaller the engine less fuel consumption
GX 160/5.5HP uses .37 GPH
GX390/12HP uses .92 GPH
Understanding bigger isn't better always unless the 5.5 is working hard or at a higher rpm then option is lesson the load on the engine or to upside.
Diesel might be a option then run a bio-fuel mixture to cut the cost. Old engines will run on lots of alternative fuels.

I basically always run it on nearly max speed so 3300 - 3600 rpm. But higher hp would make it have to work less hard, but i guess fuel usage would still go up?
 

Reed Lukens

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A P180 runs fine on a 4hp motor. It runs fine with a T80 added on a 5hp motor and then with a Gast compressor with the 6.5. If you are just running the P180 pump, then a smaller motor would save some gas.
 

russau

Gold Member
May 29, 2005
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St. Louis, missouri
Maxing out your RPM on the engine isn't the way to run these engines ! SLOW it DOWN and save, and you'll have better recovery rates to boot ! AND you'll save on wear and tear on your equipment plus less noise to put up with !!
 

russau

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I thought about doing just that back when.... but gasoline was more accessible for me and had other gasoline equipment and I didn't want to add to much to my list of equipment that I hauled around the Country !
 

principedeleon

Sr. Member
Oct 22, 2013
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So the engine i have now is a 6hp honda, it runs a keene p180 and does a great job at running it.. BUT i feel it uses too much fuel, especially for the amount of gold i get back 😭
😆
So my question is what would happen if i would get a bigger hp engine say a 12hp or even bigger and then make the shaft smaller i guess so the pump still fits on it, or get a diesel which i guess should be even more efficient? I'm also thinking about modifying the engine with a better air filter etc etc, but i have no idea what mods would be overkill and not really do much.

Any ideas or suggestions?
The way i been able to deal with it has been making a subbie dredge which could use a smaller pump to run.. so for a 4" dredge that normally is around less then 10 feet DEEP ; you could use a 4hp engine.. if you want to keep the bigger dredge and dont mind addng extra weight Diesel is the best thing you could do. These engines are really heavy but with just couple gallon of diesel you could spend the whole week dredging..
 

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Flatline

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Aug 31, 2021
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Maxing out your RPM on the engine isn't the way to run these engines ! SLOW it DOWN and save, and you'll have better recovery rates to boot ! AND you'll save on wear and tear on your equipment plus less noise to put up with !!
Yep, noticed that from doing a bit more research.
 

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Flatline

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Aug 31, 2021
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The way i been able to deal with it has been making a subbie dredge which could use a smaller pump to run.. so for a 4" dredge that normally is around less then 10 feet feet; you could a 4hp engine.. if you want to keep the bigger dredge and dont mind addng extra weight Diesel is the best thing you could do. These engines are really heavy but with just couple gallon of diesel you could spend the whole week dredging..


Yes, been looking into that also it seems you could almost run a full day on some engines. And the chinese ones are pretty cheap, but yep they do weigh a bit. But i can't seem to find a middle ground one, i found a 4hp one and then a 10hp one, i would need something in between i think if i'm going with a 5inch nozzle.
 

principedeleon

Sr. Member
Oct 22, 2013
449
151
Yes, been looking into that also it seems you could almost run a full day on some engines. And the chinese ones are pretty cheap, but yep they do weigh a bit. But i can't seem to find a middle ground one, i found a 4hp one and then a 10hp one, i would need something in between i think if i'm going with a 5inch nozzle.
yeah i noticed the same thing specially in weight.. because in HP there's these 5HP , 9HP and a 12HP but they all weight about the same.. the 4hp one is the lightest diesel i seen weighting in around 50 pounds. but it would be tiny for a surface 4" dredge. they bigger ones could run a 5" surface or 6" subbie.
 

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Flatline

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Aug 31, 2021
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yeah i noticed the same thing specially in weight.. because in HP there's these 5HP , 9HP and a 12HP but they all weight about the same.. the 4hp one is the lightest diesel i seen weighting in around 50 pounds. but it would be tiny for a surface 4" dredge. they bigger ones could run a 5" surface or 6" subbie.
Yeah, i'm probably going to build myself a 5" it looks like i just need to move more damn material! And a bigger 9Hp diesel should handle that with ease.
 

russau

Gold Member
May 29, 2005
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St. Louis, missouri
I just heard on T.V. that some socalled politician were wanting to turn 150 miles of the Mississippi River into a National Park ! This would be including in front of the Gateway Arch in St. Louis , Mo....! That would end my thought's of building a BIG dredge and doing some sniping
 

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Flatline

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Aug 31, 2021
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I just heard on T.V. that some socalled politician were wanting to turn 150 miles of the Mississippi River into a National Park ! This would be including in front of the Gateway Arch in St. Louis , Mo....! That would end my thought's of building a BIG dredge and doing some sniping
I'm in sweden so no problem :D And we have our claim in finland :D
If anyone want's to look it up we have a facebook page called Camp Skäggwood https://www.facebook.com/groups/1948201855459551/
 

submerged

Jr. Member
May 20, 2005
75
5
Fishkill N.Y.
So the engine i have now is a 6hp honda, it runs a keene p180 and does a great job at running it.. BUT i feel it uses too much fuel, especially for the amount of gold i get back 😭
😆
So my question is what would happen if i would get a bigger hp engine say a 12hp or even bigger and then make the shaft smaller i guess so the pump still fits on it, or get a diesel which i guess should be even more efficient? I'm also thinking about modifying the engine with a better air filter etc etc, but i have no idea what mods would be overkill and not really do much.

Any ideas or suggestions?
I have the same engine on my grandsons mini bike I put an AMR500 roots style supercharger on it from Amazon $125. It runs 2x the HP 2x faster and much less gas used it pulls crazy wheelies with me and I’m 260lbs. Just a little welding
 

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Flatline

Jr. Member
Aug 31, 2021
29
18
sweden
Primary Interest:
All Treasure Hunting
I have the same engine on my grandsons mini bike I put an AMR500 roots style supercharger on it from Amazon $125. It runs 2x the HP 2x faster and much less gas used it pulls crazy wheelies with me and I’m 260lbs. Just a little welding
I guess you have removed the governor then too? I wont as the pump is rated at 3600 rpm so running faster than that might make it break.
 

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