Wardbrook I have a bit of a unique situation. I am trying to run a circular sawmill off the rear axle of a 1983 300D. 

I need a constant saw speed of 540rpm under varying load conditions, ie: free spinning blade to buried in a hardwood log. For this I need a motor speed of roughly 3000rpm. 

Much original plan was to use a Rostra Universal cruise control kit to govern. However in practice this did not work as I intended. The rpm wasn’t all over the map it would not hold steady above 1200 rpm or so. I  then just tried to just use the accelerator pedal to slowly bring the rpm up to 3000 and hadn’t much difficulty. Same thing I can slowly bring it to 1200 or so and then it takes off like a rocket to 4000rpm if you don’t let off. This is with rear end in the air and car in gear but no real load. So I thought ok my foot just isn’t sensitive enough so I got out a small turnbuckle and hooked it up the the throttle linkage. Same results I can be at 1000 rpm and then turn the turnbuckle 1/8 turn tighter and I get a slight pause followed by the engine running away until I let the throttle back in. 

It should be evident by now that clearly I have very little knowledge about the magic of an IP. But evidently we are not in Kansas anymore, it’s nothing like a carburetor... it is now obvious to me that throttle position is not directly correlated to rpm in a no load/light load condition. This rules out an electronic cruise control every being a possibility. Almost any industrial governor option I know of such a small for a generator or compressor also use throttle linkage actuation to function.

So how do I make this work?
 
One thought I had was to mod the injection pump.  From what I understand there is a high idle setting that’s governs max rpm. If I couldn’t set this to 3000rpm much thoughts are I could have two throttle settings, idle and wide open throttle. At WOT the IP would then hold the rpm for me at various loads.

So does anyone know if A. this would work, and B. If there is even this much adjustment in that setting.

Anyone have a better reasonably low cost solution?

(05-29-2020, 12:58 AM)zeeman What about a governor from a diesel generator. They have to be kept at a certain RPM under various loads.

(05-29-2020, 12:23 AM)NZScott I cannot see any reason why an electronic cruise control wouldn't work, it would work exactly how it would move a throttle cable (assuming its not a version meant for electronic TBs). You'd just have to set the hysterisis (sensitivity) somehow

(05-29-2020, 09:17 AM)barrote U need a farm tractor governor, as all tractors have a variable load konstant speed governor...
Many jonh deere use type A pumps wich is much similar to mw pump. Just hook it anf that it. Or find a pump from 5 cyl tractor any will do ... fit it and thats all...
No car in the world have variable load governors...
M pumps have rsf/rsv/rsq c governors... but as i said M pump is automotive so u wont find any with a variable load unit.
Generators have only 2 speed , off load and onload .
Onload is set at best SFC acording to generator unit HZ, in EU is 50.00 more or less .05
Maybe u just can spend your money in a 40year old farm tractor

(05-29-2020, 11:25 AM)Wardbrook

(05-29-2020, 09:17 AM)barrote U need a farm tractor governor, as all tractors have a variable load konstant speed governor...
Many jonh deere use type A pumps wich is much similar to mw pump. Just hook it anf that it. Or find a pump from 5 cyl tractor any will do ... fit it and thats all...
No car in the world have variable load governors...
M pumps have rsf/rsv/rsq c governors... but as i said M pump is automotive so u wont find any with a variable load unit.
Generators have only 2 speed , off load and onload .
Onload is set at best SFC acording to generator unit HZ, in EU is 50.00 more or less .05
Maybe u just can spend your money in a 40year old farm tractor

Two speed is essentially what I need, idle and 3000rpm (which through gearing gets me 540rpm blade speed) the blades are dished to run at a certain rpm, higher or lower they will not run true.

I understand that no car is going to have a proper governor to do this as it’s not something a car needs to do. Some work trucks with auxiliary hydraulics or other PTO run devices have this but no passenger vehicle. I mistakenly thought I could use a cruise control to cheat it but for whatever reason as I stated the throttle position is not directly correlated to engine rpm so this doesn’t work at all how I envisioned. Sounds like maybe an A pump would work but I suspect that’s far from a bolt on mod...pumps aren’t exactly cheap either.

Why wouldn’t lowering the max RPM setting work? If it could limit max rpm to 3000 I could mash the throttle and have it hold at 3000 regardless of load or let off and idle. Two settings full on, and off. I do believe you this won’t work I am just curious why it won’t.

(05-29-2020, 01:14 PM)nastala The internal springs of the governor all interact, and if one of them is adjusted far out of the original spec, it will affect the rest. It's possible it could work, but I bet you'll find many other problems. The MW pump actually uses the RW governor on the OM617 (as far as I know), and there should be a few other governors that can bolt up the the MW housing. You could find one of these on ebay probably, or swap it over from a different pump. All information about these other governors is on the W-Archive. I've always wondered if the EDC governor can bolt up to the MW-pump, as that would allow anything to happen, both in a 300D and in whatever industrial purpose you desire.

(05-29-2020, 10:40 PM)NZScott

(05-29-2020, 01:14 PM)nastala The internal springs of the governor all interact, and if one of them is adjusted far out of the original spec, it will affect the rest. It's possible it could work, but I bet you'll find many other problems. The MW pump actually uses the RW governor on the OM617 (as far as I know), and there should be a few other governors that can bolt up the the MW housing. You could find one of these on ebay probably, or swap it over from a different pump. All information about these other governors is on the W-Archive. I've always wondered if the EDC governor can bolt up to the MW-pump, as that would allow anything to happen, both in a 300D and in whatever industrial purpose you desire.

Of course! I forgot the MW pump was used on other non vehicle engines (IH DT466 comes to mind). Yes surely some industrial engine (rather than truck) with an MW pump would have a governor that should bolt onto the back of the 617 pump?

(05-29-2020, 10:51 PM)nastala If anyone is interested, I can get a list of every MW-pump engine application and what governor it uses.

(05-31-2020, 11:25 AM)OM616 Do I understand you correctly in that the engine is in the car still? 

Although, as has been pointed out, the RW governor is not intended to work as you need, I think it may be possible to make it get you close enough to what you need, BUT, you will need special tools and will have to get into the back of the pump and make some adjustments many times. I would wager that a weaker High Speed governor spring will be needed.

I am thinking if you were to back off the Torque Control and reduce the High Speed governor spring tension that you may be able to run within the range of the High Speed governor. 

Do you have any idea how much power you need to make?  

The simplest solution is to just have a throttle-man.

(05-31-2020, 08:31 PM)Wardbrook

(05-31-2020, 11:25 AM)OM616 Do I understand you correctly in that the engine is in the car still? 

Although, as has been pointed out, the RW governor is not intended to work as you need, I think it may be possible to make it get you close enough to what you need, BUT, you will need special tools and will have to get into the back of the pump and make some adjustments many times. I would wager that a weaker High Speed governor spring will be needed.

I am thinking if you were to back off the Torque Control and reduce the High Speed governor spring tension that you may be able to run within the range of the High Speed governor. 

Do you have any idea how much power you need to make?  

The simplest solution is to just have a throttle-man.

 

That is correct, engine is in the complete car I have just made an adapter that bolts in place of one rear wheel which has a tractor PTO shaft 6 spline male output. 

I think about 50-60hp would be more than I need in most scenarios. I was previously running the mill on a 30hp diesel tractor which was not quite up to the task. I could cut smaller logs but if the blade was fully buried it did not have the grunt. 

Throttle man is not really a feasible option for one the mill is a one man operation I don't have anyone to help most of the time. But also it really needs to stay in a pretty fine window of operation at 540rpm blade speed. The blades are hammered into a dish which only runs true at the correct RPM, too fast or too slow and it will heat on either the hub or outer edge and cause lots of expensive problems as well as poor cutting.