Kohler 85R78 with UV549 IH Power

[Karl Kohler]

Kohler 85R78 with UV549 IH Power

I have been reading the hundreds of threads on old Kohler generators and have to compliment Harry and those of you who have participated in the discussions…your accumulated knowledge on these machines is remarkable! Without your help this project wouldn’t be. Thanks to all!

I recently bought an old Kohler generator…I hope to use it for backup at my home. The unit appears to be well maintained, indoors, it’s a fresh water cooled, natural gas V8. I’ve added a radiator/fan setup…since the coolant runs through the exhaust manifolds…and exits each manifold separately…I’ve made a “Y” pipe to route the manifold water into the top of the radiator. Does anyone have any experience with this?

I’m limited to propane…so I’ve converted it over. It will use propane rapidly…possibly freezing up the tank…so I bought 2-250 gallon tanks…ran them through one 2.5 million BTU regulator (3/4” outlet). I’m in Arkansas…our lows usually get down into the 20’s…Does this sound like it should work?

I’ve rewired it from the original 470 volts 3 phase to the Low Zigzag single phase configuration. Hopefully I’ll be able to get the voltage I’m looking for. I bought (ebay) and installed a 260 amp Asco automatic transfer switch in the house. Although it’s supposed to only switch over to the emergency power after the output has been verified…I’m still going to be selective about what appliances are powered up during the test. I’ve got 2 kitchen ranges I can use for an initial load test.

I’m looking for schematics…Just like most everyone else the Kohler dealer told me I was on my own. I e-mailed Jim Moersch at Kohler and he quickly mailed back that the books were available for this unit and he would contact my local dealer and provide them with the part numbers.

Just like Christmas…I’m much to excited about cranking it up…to wait around for instruction books!

Here are the generator specifications:

Model: 85R78
Spec: 57408A29
Serial: 318609
Controller: A284362
KW: 75
Phase: 3
Cycles: 60
Volts: 277-480
PF: .8
Battery: 12V

Any advice will be appreciated…and thanks a lot for a great website!

Karl

[K D Redd]

To keep your tanks from freezing up look for a demand regulator which uses cooling water to heat it. This type of demand regulator is supplied with liquid LP from the tank. This is the way all LP fuel farm equpment was set-up. You might find a used one around a place that salvages school buses. In the 70's many school buses were set-up dual fuel with LP and would have a regulator you might be able to use. If you can not find one from a big enough engine I saw a 4 wheel drive puller, who ran LP, use two regulator on his engine.

Kent

[Jim Rankin]

Adding the exhaust manifold heat to the radiator will require a bigger radiator than normal, but your continuous house load is unlikely to be very much over 20% of full capacity 3 phase, so you may be fine there.

I have an older? 75kW Kohler thanks to Steve that I would like to convert to 240V 3 phase one day. Haven't had time to dig into it yet. I'll compare numbers today, but mine is 24V so it's probably older and may be a completely different exciter/regulator. It has a DC exciter mounted on the rear of the generator which sticks out under the control panel.

[Karl Kohler]

Kent,

Thanks for the advice. I will look around for one. Although it makes sense, that whole liquid/gas thing goes right over my head. Just one more thing on my future reading list!

Karl

[Karl Kohler]

Originally Posted by Jim Rankin

Adding the exhaust manifold heat to the radiator will require a bigger radiator than normal, but your continuous house load is unlikely to be very much over 20% of full capacity 3 phase, so you may be fine there.

I have an older? 75kW Kohler thanks to Steve that I would like to convert to 240V 3 phase one day. Haven't had time to dig into it yet. I'll compare numbers today, but mine is 24V so it's probably older and may be a completely different exciter/regulator. It has a DC exciter mounted on the rear of the generator which sticks out under the control panel.

Jim,

I used a 4 core radiator from a 1 ton Ford truck. Hope it’s big enough. It sure looks good!

An e-mail just came through from Jim Moersch at Kohler…he has already put my books in the mail…unbelievable! I just requested them 2 days ago. He did write that they were not specific to my set…but everything I need should be in there. His best guess is that the set was built in ’68 and the book says I may have a problem reconnecting to single phase because I could need a new exciter and regulator…which may not be available anymore. I’ll check it out when the books arrive.

I just got the generator 3 days ago, but I think it has a different exciter than yours. I think it’s right inside the grill at the end of the generator head.

I have to tell you, I was surprised at the condition and size of the generator when I picked it up from the trucking company. It looks more like 5 years old not 37…and its 2700 pounds was quite a load on my SUV!

I have no idea what Jim Moersch is sending me…you may already have it…but I will be glad to copy you with anything that pertains to your unit. Just forward me your numbers.

Karl

[Jim Rankin]

http://www.smokstak.com/forum/showth...482#post102482

Picture of a vaporizer Impco E and a thread about this.

[Karl Kohler]

Thanks for your help everyone. I'm wired, plumbed and load tested. I did have to give the exciter an initial charge to get it going. After 1/2 hour of running with a 90 amp load...the engine coolant temperature (200) tripped the limit switch and shut the unit down. Since it was fresh water cooled before...I was just guessing that a 4 core 1 ton truck radiator would be enough. Back to the drawing board! My new plan is to add another duplicate radiator and mount them side by side in the back wall of the shed. I will plumb them in series and cool them with 115 volt fans, using the unused third leg of the three phase generator output. Hopefully this will be enough cooling. With the one radiator setup...mounted on the generator skid...it took 9 gallons of a 50/50 mixture of coolant. I'll be crying when I pay for the antifreeze it will take to fill this new setup.

Regards,

Karl

[Jim Rankin]

Great! Hope you can make it work. I wonder if the standard water pump will circulate enough water through the remote radiators and piping or if you will have to have an auxillary pump in the circuit? Probably wouldn't take much of a pump to do it.

[Robert Ward]

Karl,

I have schematics on a 85R88, 75KW, 549 V8, static exciter genset if you think they will help. I can email them if you can open Adobe.

Bob

[KidDynamo]

Factory tested and proven cooling systems are easily taken for granted but sometimes when they are altered things don't go so well.

V-8 engines also have two banks which need to have cooling water go through them in approximately the same amount and if this gets disrupted and one bank "hogs" too much cooling water flow, problems can develop.

A lot of V-8's plumb the temperture sensors into one cylinder head and don't measure the water temp from the other head. I have seen imbalances where the head with the senser was cooling just fine but the other head was running way too hot. It all depends on how it is arranged. Ditto with thermostats and coolant by-pass circuits.

The same thing can happen with water cooled manifolds where one or both of them either "hog" too much coolant flow or perhaps don't get enough coolant flow. It can disrupt the entire cooling system. Consider the location of the thermostat and your temp sensers also. What exactly are the flow effects on them....?

I've been down this road a few times. You might consider running your engine as plumbed and take temp readings all over the engine to see where the heat build up is occurring. Use your hand or a digital infra-red temp sensor like a Fluke. It may surprise you to see how temps can vary in a system that isn't working correctly.

A bigger radiator may not help if coolant flow is unequally distributed. Also, the thermostat bypass flow needs to be taken into consideration too. Also, if the average angle of installtion of the engine is radically changed, this can create probelm sometimes. Head gasket steamholes can vary on similar engines according to the design intent of the engine.

This is a topic that can be a little hard to condense into a few paragraphs. I'm just trying to present some of the factors that can go into solving a cooling problem when there have been modifications. It is possible to go to some great trouble and expense installing added radiator capacity only to find that a small, carefully located flow restricter was what was needed or maybe re-routing some plumbing so the thermostat actually sensed real heat load.

When you change cooling and it works first time you forget about it. Sometimes you make changes and they can be a little harder to solve.

I hope yours is easy as pie!!!

[Karl Kohler]

Thanks for your help guys...I need all I can get. I'll let you know what I end up with.

Karl

[Frank DeWitt]

You mention that your exciter may not work for signal phase. Should that unfortunate thing happen you might get some help from
http://www.power-tronics.com/
They make after markert exciters that can be fitted to almost any generator.

They also have a great web site on trouble shooting and plans to build your own tester.
http://www.power-tronics.com/help%20files/testsetpg.htm

Frank DeWitt

[Robert Horstmeier]

Originally Posted by Jim Rankin

Adding the exhaust manifold heat to the radiator will require a bigger radiator than normal, but your continuous house load is unlikely to be very much over 20% of full capacity 3 phase, so you may be fine there.

I have an older? 75kW Kohler thanks to Steve that I would like to convert to 240V 3 phase one day. Haven't had time to dig into it yet. I'll compare numbers today, but mine is 24V so it's probably older and may be a completely different exciter/regulator. It has a DC exciter mounted on the rear of the generator which sticks out under the control panel.

DEAR SIR; I was in the engineering dept. at Fairbanks Morse in the 1960's
and we used a lot of UV549 IH engines and they top of the line. The LP and NATURAL GAS engines were very high compression and the timing was
advanced a lot more than gasoline engines. The kohler older gen-sets
were gen. cranked per the PENN. state specs. The PENN state gen-set
specs were wrote around the Kohler specs so they had a captive market.
The single phase units are only 58% efficient, so the generator was double
size compared to a 3 phase. The engine was derated also because it took over 2 HP per KW.
I do not know if I helped you or not, I hope I did????

[Robert Horstmeier]

Originally Posted by Karl Kohler

Kohler 85R78 with UV549 IH Power

I have been reading the hundreds of threads on old Kohler generators and have to compliment Harry and those of you who have participated in the discussions…your accumulated knowledge on these machines is remarkable! Without your help this project wouldn’t be. Thanks to all!

I recently bought an old Kohler generator…I hope to use it for backup at my home. The unit appears to be well maintained, indoors, it’s a fresh water cooled, natural gas V8. I’ve added a radiator/fan setup…since the coolant runs through the exhaust manifolds…and exits each manifold separately…I’ve made a “Y” pipe to route the manifold water into the top of the radiator. Does anyone have any experience with this?

I’m limited to propane…so I’ve converted it over. It will use propane rapidly…possibly freezing up the tank…so I bought 2-250 gallon tanks…ran them through one 2.5 million BTU regulator (3/4” outlet). I’m in Arkansas…our lows usually get down into the 20’s…Does this sound like it should work?

I’ve rewired it from the original 470 volts 3 phase to the Low Zigzag single phase configuration. Hopefully I’ll be able to get the voltage I’m looking for. I bought (ebay) and installed a 260 amp Asco automatic transfer switch in the house. Although it’s supposed to only switch over to the emergency power after the output has been verified…I’m still going to be selective about what appliances are powered up during the test. I’ve got 2 kitchen ranges I can use for an initial load test.

I’m looking for schematics…Just like most everyone else the Kohler dealer told me I was on my own. I e-mailed Jim Moersch at Kohler and he quickly mailed back that the books were available for this unit and he would contact my local dealer and provide them with the part numbers.

Just like Christmas…I’m much to excited about cranking it up…to wait around for instruction books!

Here are the generator specifications:

Model: 85R78
Spec: 57408A29
Serial: 318609
Controller: A284362
KW: 75
Phase: 3
Cycles: 60
Volts: 277-480
PF: .8
Battery: 12V

Any advice will be appreciated…and thanks a lot for a great website!

Karl

DEAR SIR: I worked in the gen-set dept at Fairbanks Morse
at Beloit WI in the engineering dept and we used many UV549 engines for
LP, NAT GAS, SEWER GAS and gasoline. Very good engine. The water cooled
manifolds add 2X to the cooling system. We used water cooled manifolds
with city water cooling for stand pipe and heat exchanger cooling and for
remote radiator set ups to keep the heat down in the building so the engine
and generator did not have to be derated. The remote radiator usually needed
a WATER BOOST pump. If you use insect screen, the radiator has to be
increased in size because the air is restricted 48%.
When you use the generator in the single phase tie-off with a 12 lead
connectible, the generator is ONLY 58% efficient and the engine is derated
to 2 HP per KW at .8 power factor.
The engine, if it was built for just LP will not have to be derated 12%.
A gasoline engine run on LP is derated 12%. An LP engine run on gasoline
will diesel and most likely destroy it's self. We used a lot of dual fuel engines
and on LP they were derated 12%.
I believe you have a very good unit. I believe you should check with
Kohler on the capacity of your unit with single phase and if the room gets very
warm. The engine will loose power with air over 60 degrees F. The generator
will run over temp also.
Water cooled manifolds with LP gas run very hot. Regular manifolds run
yellow with LP or NAT GAS and heat the room to unbearable temp.
GOOD LUCK WITH YOUR PROJECT. WHEN YOU GET ALL THE BUGS OUT
YOU MIGHT BE ABLE TO SELL POWER TO THE PEOPLE IN YOUR AREA IF
THERE IS ANOTHER STORM.

[Gunny]

Couple of thoughts here.
With water cooled manifolds, double the size of the radiator.

If the engine has been run with only fresh water as a coolant, you may want to descale the cooling system. Careful with a machine this old, you may end up with some leaks but they can usually be easily stopped with water glass. Would not run it with just water in the cooling system, that stuff is very corrosive at higher temperatures and causes the inside of the engine to rot out in short order.

Timing is critical. I have found the best way to get the timing right is to use a vacum gauge. Run the engine at no load with a vacum gauge reading mainifold vacum. Adjust timing to get the highest reading, lock it down and let her run.

[Karl Kohler]

Thanks for the help guys. I completed my remote, twin radiator set-up last week and load tested it at 90 amps for an hour. Once warm, engine temperature ran at a steady 170 degrees without any variation. Sometime when my wife isn't home I'll test it longer. 90 amps equals both of her electric range/ovens being cranked up...which makes it uncomfortably hot in the house.

With the twin radiator setup, I'm using 17 gallons of 50/50 antifreeze mixture. I had run some automotive cooling system flusher through the system before I went to the remote radiators so hopefully I got any sludge and some of the scaling out. I do have water cooled exhaust manifolds, so the generator doesn't seem to radiate an abnormal amount of heat. Most of the heat that does radiate off of the generator is from the 4" exhaust pipe that I've got routed through a muffler and then out of the shed. If I can figure out how to do it, I will attach some pictures of the system with my next post.

I do have a question someone may have an answer to. The first time I fired up the generator a month or so ago, I got no voltage. Because of all of the valuable info on this site, I determined that I needed to charge the exciter. Sure enough...it worked. During the time I've been working on it, it gets started every couple of days...just for fun if nothing else. How do I know the exciter is going to be charged when I really need it...after the thrill is gone and I am working on another project? This unit uses a static exciter and regulator.

Karl

[Dan R]

Karl,
Your generator should excite itself during start-up. There should be a wire running from terminal 20 in the control cabinet down to the exciter in the generator. I believe 12 volts will be supplied to the exciter field by this wire at start-up. When A.C. output is sensed on wires 8 & 11, relay 3cr will energize and disconnect this field flash circuit. The voltage regulator will now take over.Hope this helps.

[Karl Kohler]

Thanks Dan!