NH 120 repowered with a Kohler CH20

I have removed the original Linamar 770 as it had broken a piston, and the other head gasket was leaking, it didn`t charge and it had too many oil leaks to deal with. I have decided to repower with some good old americian know how and go with a Kohler. The problem I am running into right now is that the original engine had a bolt pattern built directly into the cast iron fly wheel that accepted the 4 bolts that connected the pump and dual pulleys directly to the motor. (I don`t know how much sense that makes, I am gonna have to get the camera and take some pics, stay tuned). The kohler engine has the option of adding an additional drive shaft to the cooling fan side of the engine allowing for mounting that will mimic the original Linamar and allow the needed space for the exahaust. Some how I need to come up with a way to mount the original dual pulley and hyd. pump mount to a 1 inch shaft. If any one has any idea of what I am talking about, I would love to hear some stories, suggestions or comments. I will be venturing out with the camera to get some pics which will no doubt help with the solution to this problem. Once again thanks in advance for all the input, I am gonna need it. I realize this is probably gonna take a trip the the machine shop but I would like to have some ideas on the ways I could connect these before I show up at the shop.......

I'm wondering how hard it would be to machine the old fly wheel down so it can be bolted to the new Kohler. You then have no issues with bolt patterns, any machine shop that knows what they are doing could machine it down to thin it out and make it fit the new engines output shaft. They could machine an adaptor plate to accept the 1" shaft and secure it to the fly wheel.
Its the route i'd go, see what ideas others have.
Lots of pictures will be required

Hi Ponyboy,
No worries, you are sure to figure this out. Like Tazza said, you need to locate a decent machine shop, as this will make your life much easier. I'm lucky to have my own available at Pop's place.
Your pulley dillema should not be a big one either, there are plenty available in the after market if you can't make your stock one work.
I may be misunderstanding you, but is your machine taking it's drive off of both ends of the crankshaft? This not too unusual, I have seen garden tractors do the same thing. I would love to see some pictures of the stock engine setup before you pull it out.
Cheers,
SR

Here is my ls 120

here is the old Linamar 770 with the cast iron fly wheel and bolt up for the pulley/pump connection

here is the pulley/pump connection that bolts up to the fly wheel



Here is the engine bay

You can see in this photo the three pump that run the beast. Top two are for right and left propulsion and the small one hanging down in the middle is the pump that runs the boom and bolts directly to the engine.

This is the new kohler engine with the side facing where the optional drive shaft bolts up. The main reason for not using the main drive on the opposite side is basically so there will be enough room to run the exahust and will make it easier to hook up the throttle and choke controls. Well this is my first attempt at posting some pics and my next post should be more organized. Keep the questions and comments coming and I can get any additional pics you need. Thanks again for all the help......

ponyboy123 said:

Here is my ls 120

here is the old Linamar 770 with the cast iron fly wheel and bolt up for the pulley/pump connection

here is the pulley/pump connection that bolts up to the fly wheel



Here is the engine bay

You can see in this photo the three pump that run the beast. Top two are for right and left propulsion and the small one hanging down in the middle is the pump that runs the boom and bolts directly to the engine.

This is the new kohler engine with the side facing where the optional drive shaft bolts up. The main reason for not using the main drive on the opposite side is basically so there will be enough room to run the exahust and will make it easier to hook up the throttle and choke controls. Well this is my first attempt at posting some pics and my next post should be more organized. Keep the questions and comments coming and I can get any additional pics you need. Thanks again for all the help......

Click to expand...

Interesting setup. I take it that the drive pumps are belt driven and the loader pump is direct drive?
Looks like an adapter flange is required, basically a piece of thick plate, machined round with the features required for the Kohler's flywheel on one side and a surface to mount the stock pulley on the opposite side. The flange would be attached to the flywheel with countersunk head machine screws, leaving a flate surface for the pulley to mount to. Does that make sense?
This would tend to push the motor a little rearward, by the thickness of the plate, but I can't see the plate having to be any thicker than 1/2" to 3/4". You would definitely need to see that machine shop about making this.
Also, does the motor turn the correct direction when you mount it like this?
Keep the updates coming!
SR

SkidRoe said:

Interesting setup. I take it that the drive pumps are belt driven and the loader pump is direct drive?
Looks like an adapter flange is required, basically a piece of thick plate, machined round with the features required for the Kohler's flywheel on one side and a surface to mount the stock pulley on the opposite side. The flange would be attached to the flywheel with countersunk head machine screws, leaving a flate surface for the pulley to mount to. Does that make sense?
This would tend to push the motor a little rearward, by the thickness of the plate, but I can't see the plate having to be any thicker than 1/2" to 3/4". You would definitely need to see that machine shop about making this.
Also, does the motor turn the correct direction when you mount it like this?
Keep the updates coming!
SR

Click to expand...

The drive pumps are belt driven, and the boom pump is direct drive. The mounting flange you talk of would certianly work, except I need at least 3" to have the clearance to get outside of the engine covers. There apears to be plenty of space to move the engine forward or backward to accomidate this process. What really interests me is if the engine will turn the correct way to power the old girl. This is something I will check out first thing in the morning. That will decide which way the engine is mounted for sure. Thanks for the input, I will try and post some more pics later.

Paul

ponyboy123 said:

The drive pumps are belt driven, and the boom pump is direct drive. The mounting flange you talk of would certianly work, except I need at least 3" to have the clearance to get outside of the engine covers. There apears to be plenty of space to move the engine forward or backward to accomidate this process. What really interests me is if the engine will turn the correct way to power the old girl. This is something I will check out first thing in the morning. That will decide which way the engine is mounted for sure. Thanks for the input, I will try and post some more pics later.

Paul

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Paul, where are you located? I noticed the Canadian Tire and Home Hardware shopping bags hanging from your machine, you have to be in Canada...
SR

SkidRoe said:

Paul, where are you located? I noticed the Canadian Tire and Home Hardware shopping bags hanging from your machine, you have to be in Canada...
SR

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Located in Nova Scotia Canada, guess the Home Hardware and Canadian Tire bags gives that away, lol. Things are getting pretty busy here on the farm so my time with my beloved skid steer is limited. I did manage to figure out that the Kholer engine has to mount in "backwards" in order to keep the rotation correct. So that makes that decision easier. I tied up a few loose ends and got the measurements I needed to order the optional output shaft so it is back to the waiting game for that to come in and then it is off to the machine shop. I will try and post some more updats when possible but there probably won't be a whole lot of skid steer work goin on till I get all these kits born, weaned, split, implanted, and vaccinated, all 20,000 of them. By then it will be August.
Cheers

ponyboy123 said:

Located in Nova Scotia Canada, guess the Home Hardware and Canadian Tire bags gives that away, lol. Things are getting pretty busy here on the farm so my time with my beloved skid steer is limited. I did manage to figure out that the Kholer engine has to mount in "backwards" in order to keep the rotation correct. So that makes that decision easier. I tied up a few loose ends and got the measurements I needed to order the optional output shaft so it is back to the waiting game for that to come in and then it is off to the machine shop. I will try and post some more updats when possible but there probably won't be a whole lot of skid steer work goin on till I get all these kits born, weaned, split, implanted, and vaccinated, all 20,000 of them. By then it will be August.
Cheers

Click to expand...

If you dont mind me asking, what did you give for the loader?