# Engine for sawmill



## cibb911

My father asked me to build him a bandsaw mill. Long story short all of our cattle fence is old and rotten the cost to replace it is very expensive so we can use our timber for the wood. 

We have a 10hp hatz diesel also a z790 hatz that is in very good shape as well. Also I have a 20hp Honda with 20amp alternator that needs rebuilding but still runs. 

The z790 is a 27hp diesel but is very large and heavy. I'd prefer to use the 10hp diesel but I feel it will be way under powered on a band mill. I'm going to use 22" band wheels and hope to have it wide enough for a 30" log. Though most of the work will be on 18-25" logs. 

I know bigger is usually better but I prefer the diesel but would the 10hp be too weak? Would you go with the Honda?

I'm not in a huge rush just doing some planning right now. 

Thanks for any help.


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## Logger

my norwood rons a 13 hp. honda and cuts well.


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## qbilder

The 10hp is out of the question, unless it's got incredible torque at full throttle. You'll want the bigger diesel or rebuild the big Honda. You'll not need the generator attached to it, just the motor. A saw that big will need power, and 10hp just won't do it. My saw is about that size with a 16hp motor & there are times I wish I had 25 or better.


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## cibb911

qbilder said:


> The 10hp is out of the question, unless it's got incredible torque at full throttle. You'll want the bigger diesel or rebuild the big Honda. You'll not need the generator attached to it, just the motor. A saw that big will need power, and 10hp just won't do it. My saw is about that size with a 16hp motor & there are times I wish I had 25 or better.


I figured the 10HP would be a bit small, even as a diesel. I'm leaning towards the gas I'm just concerned about the size of that engine, the z790 diesel. I feel it would be over kill.

I'm going to add a hydraulic log loader, think the 20amp Alternator would do enough charging for a log loader? I'd have the battery fully charged to start with so it would just need to help keep it from being completely drained.


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## ETWW

My mill has a 13 hp Honda clone (Jingdong) and saws pretty well on big logs if I take it slow. I'm already thinking of upgrading to an 18 hp engine. You can saw 30" hardwood logs with a 10 hp mill but it will take a long time. I think re-building the 20 hp Honda would be your best option.

If you are anywhere close to Northeast Texas, I have a bed for a manual mill that I would let go very cheap. It has three clamps/log stops and was mfg by Logmaster in Nacogdoches, TX. I had a trailer built for my LM-1 mill and have no use for the stationary bed. It will handle 12' logs with the LM-1 head rig on it. PM me if you are interested.


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## Tommie Hockett

dude you have got to do a build thread on this when you start:yes::thumbsup:


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## qbilder

Yeah the alternator should be ok, possibly even up it to a 90 or 100amp automotive alternator. The diesel isn't too small, especially for the size of the mill. If it's big enough & heavy enough to support hydraulic log handlers, then your diesel isn't overkill. The gas motor would work, too. Worse thing would be to build the mill & find out that you need more power, and have to modify it. 50hp diesel engines are not uncommon on hydraulic saws, so your 20 something hp is not overkill.


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## cibb911

Tommie Hockett said:


> dude you have got to do a build thread on this when you start:yes::thumbsup:


I fully intend to. I've got several projects I'm working on so this one is going to take a while. I intend to have some fairly detailed pics and write up on it.


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## cibb911

qbilder said:


> Yeah the alternator should be ok, possibly even up it to a 90 or 100amp automotive alternator. The diesel isn't too small, especially for the size of the mill. If it's big enough & heavy enough to support hydraulic log handlers, then your diesel isn't overkill. The gas motor would work, too. Worse thing would be to build the mill & find out that you need more power, and have to modify it. 50hp diesel engines are not uncommon on hydraulic saws, so your 20 something hp is not overkill.



The z790 is a military surplus engine, it would likely need rebuilding as well. The engine is very heavy, fully assembled it weights in 200-300 pounds, I'm leaning towards the gas due to it being lighter but I'd really prefer the diesel.


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## Tommie Hockett

cibb911 said:


> I fully intend to. I've got several projects I'm working on so this one is going to take a while. I intend to have some fairly detailed pics and write up on it.



Well in that case your are my new best friend:yes:


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## qbilder

Maybe keep an eye out for a cheap motor. Heavy isn't bad but too heavy is bad. I'd think a 20-30hp mower or generator engine would do you fine. My 16hp does the job. 20 would be better. 25hp would leave me not wanting.


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## Alchymist

Seen a number of them with Volkswagen engines.


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## harrymontana

too small or too big engine depends on the kind ofwood you are going to cut, we use for example a 30HP for cutting up the 2" thick hardwood (ipe, massaranduba, tigerwood). 
As far as I understand I don't think there is a difference between electric or diesel/ gas/ gasoline driven, it is just about the HP


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## scsmith42

harrymontana said:


> too small or too big engine depends on the kind ofwood you are going to cut, we use for example a 30HP for cutting up the 2" thick hardwood (ipe, massaranduba, tigerwood).
> As far as I understand I don't think there is a difference between electric or diesel/ gas/ gasoline driven, it is just about the HP


Harry, electric models develop about 20% more torque (equivalent HP), and it makes a real difference in the cut on large hardwood logs.


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## harrymontana

I am sorry, what is exactly the difference, the powersavings (you get 20% more) or is is the stability of the powersupply (does not go on and off like with filthy diesel)?


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## scsmith42

harrymontana said:


> I am sorry, what is exactly the difference, the powersavings (you get 20% more) or is is the stability of the powersupply (does not go on and off like with filthy diesel)?


From a practical perspective, once the blade is in the cut torque becomes more important than horsepower in terms of maintaining the best cutting speed.

So when comparing power choices for mills, it's best to look at both torque and HP numbers. 

Electric motors develop more torque per HP than gas engines. Typically a 16hp electric motor provides the same torque as a 20hp gas engine.

Most of the large stationary commercial mills run off of electric motors instead of diesel engines. Electric mills are cheaper to operate and have less maintenance needs.

Diesel / gas powered mills are better suited for remote locations w/o electricity, or portable needs.


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## harrymontana

scsmith42 said:


> From a practical perspective, once the blade is in the cut torque becomes more important than horsepower in terms of maintaining the best cutting speed.
> 
> So when comparing power choices for mills, it's best to look at both torque and HP numbers.
> 
> Electric motors develop more torque per HP than gas engines. Typically a 16hp electric motor provides the same torque as a 20hp gas engine.
> 
> Most of the large stationary commercial mills run off of electric motors instead of diesel engines. Electric mills are cheaper to operate and have less maintenance needs.
> 
> Diesel / gas powered mills are better suited for remote locations w/o electricity, or portable needs.


thank you, very informative


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