240D engine to be used for a Generator (info needed) - Page 3 - PeachParts Mercedes-Benz Forum

80's old school · #31 02-17-2009, 08:48 PM

Quote:

Originally Posted by Rashakor

Actually in a cold winter storm like in Massachusetts back in Dec, i would rather prefer to have a water-cooled engine than an air cooled engine. At least you can actually make a derivation on the water circuit of the motor and used that heat that would be otherwise wasted, hence saving electricity for other purposes.
I look forward for the inputs from this thread.

Well I am going to keep it coming. I will hbe getting the car either this weekend or next. To all of you 240D afficianados, this car is beyond restoring economically. The transmission is toast, and the body was seriously vandalized. (People jumping on the roof and hood). I will get parts I could use on my 300.....maybe look at replacing my messed up power windows with the manual from the 240. Also he said his odometer worked...mine does not. Maybe I will do some swapping there as well.

My big this is I wished there was some commercially available coupling from the engine to the genset. It sucks that I will have to fab this up.

I plan on using the Mercedes radiator, oil cooler, vacuum pump (possibly for cruise activation) I may also employ some kind of air compressor to this skid unit. I will be placing this unit on a trailer and setting it up to weld as well. Would be nice to have compressed air as well. I thought about using the AC compressor to build pressure, but I do not feel the CFM will be sufficient.

lutzTD · #32 02-17-2009, 10:24 PM

Quote:

Originally Posted by 80's old school

Well I am going to keep it coming. I will hbe getting the car either this weekend or next. To all of you 240D afficianados, this car is beyond restoring economically. The transmission is toast, and the body was seriously vandalized. (People jumping on the roof and hood). I will get parts I could use on my 300.....maybe look at replacing my messed up power windows with the manual from the 240. Also he said his odometer worked...mine does not. Maybe I will do some swapping there as well.

My big this is I wished there was some commercially available coupling from the engine to the genset. It sucks that I will have to fab this up.

I plan on using the Mercedes radiator, oil cooler, vacuum pump (possibly for cruise activation) I may also employ some kind of air compressor to this skid unit. I will be placing this unit on a trailer and setting it up to weld as well. Would be nice to have compressed air as well. I thought about using the AC compressor to build pressure, but I do not feel the CFM will be sufficient.

The Jeep guys use York compressors for offroad air and seem to get a pretty good flow rate from them. If you get teh stand up ones they even have their own oil res in the bottom.

strelnik · #33 02-17-2009, 11:13 PM

Quote:

Originally Posted by lutzTD

seems like you could rig the cruise control to be a governor, all those parts are already there

The 240D originally came with a Bowden cable arrangement to act as a high idle at start up to speed up bring the engine to full operating temp. It is vert easy to bring that engine to that speed by just adjusting nthe point where the cable connects.

Alternately you could increase the overall basic speed of the vehicle by changing the fuel delivery on the injection pump itself.

I can't imagine this would be necessary but under extreme conditions you could ensure fast start up by heating the engine using the block heater and starting almost at 1500 rpm, then going the rest of the way to 1800 rpm shortly therafter, assuming that your genset had its own lube set-up so that it is not adversely affected by friction as the engine speeds up to its "cruising" rpm for the genset.

Then all you would need is your post production equipment, such as voltage regulator, fuse box, plug ins to the mains etc, etc.

Many DB engines have had multiple uses (especially the OM 636, OM 516, 616, M121 and M180) and the 240s were used for trawler-type constant-speed marine applications in Europe. I am sure the fuel inj pump and governor set up were different but I think this engine would work fine for your application if it could power a trawler.

babymog · #34 02-18-2009, 12:01 PM

My first (Blue Bird) coaches came with a perkins I-4 diesel powered 12.5kva genset. It ran at 1800rpm, the noisiest thing was the (240vac powered) cooling fan.

A squirrel-cage furnace-type fan is better, best if you can use a 2-speed that is on low constantly with high controlled by a temp-sensor.

All commercial gensets have a shutoff for low oil pressure and high coolant temp. This can be done easily with a couple of relays and a Tee for extra sensors. The oil-pressure would kill the engine so you need to hold the start button down until it builds oil pressure in this simple iteration, and replace the vacuum shut-off with a 12v solenoid which will turn the engine off when not energized.

The engine should be fairly efficent at 1800rpm, but be careful to not "lug" the engine. This engine is currently designed for automotive operation, the cooling system and lubrication system aren't set up for extended full-output at low (1800) RPMs.

As far as efficiency, much of this engine is designed to be efficient at higher RPMs, and will therefore need re-tuning to create more efficiency at low RPMs. This can include many things such as: combustion chamber design, valve timing, pre-chamber design, injection timing and injection rate, injector pop-pressure. If you want to use it for more than occasional use and are interested in improving efficiency there are probably some generator and refrigeration unit gurus who can help. At very least I would consider the oil pressure at those RPMs and water flow, might be wise to replace the oil pump with a higher-volume pump and put a smaller pulley on the water pump (or larger on the crank).

Thanks for sharing your project so far, it helps some of us live vicariously though you.

80's old school · #35 02-18-2009, 01:35 PM

Quote:

Originally Posted by babymog

My first (Blue Bird) coaches came with a perkins I-4 diesel powered 12.5kva genset. It ran at 1800rpm, the noisiest thing was the (240vac powered) cooling fan.

A squirrel-cage furnace-type fan is better, best if you can use a 2-speed that is on low constantly with high controlled by a temp-sensor.

All commercial gensets have a shutoff for low oil pressure and high coolant temp. This can be done easily with a couple of relays and a Tee for extra sensors. The oil-pressure would kill the engine so you need to hold the start button down until it builds oil pressure in this simple iteration, and replace the vacuum shut-off with a 12v solenoid which will turn the engine off when not energized.

The engine should be fairly efficent at 1800rpm, but be careful to not "lug" the engine. This engine is currently designed for automotive operation, the cooling system and lubrication system aren't set up for extended full-output at low (1800) RPMs.

As far as efficiency, much of this engine is designed to be efficient at higher RPMs, and will therefore need re-tuning to create more efficiency at low RPMs. This can include many things such as: combustion chamber design, valve timing, pre-chamber design, injection timing and injection rate, injector pop-pressure. If you want to use it for more than occasional use and are interested in improving efficiency there are probably some generator and refrigeration unit gurus who can help. At very least I would consider the oil pressure at those RPMs and water flow, might be wise to replace the oil pump with a higher-volume pump and put a smaller pulley on the water pump (or larger on the crank).

Thanks for sharing your project so far, it helps some of us live vicariously though you.

Thanks for the info Jeff. Definitely something to think about!!!

lutzTD · #36 02-25-2009, 09:09 PM

Quote:

Originally Posted by babymog

My first (Blue Bird) coaches came with a perkins I-4 diesel powered 12.5kva genset. It ran at 1800rpm, the noisiest thing was the (240vac powered) cooling fan.

A squirrel-cage furnace-type fan is better, best if you can use a 2-speed that is on low constantly with high controlled by a temp-sensor.

All commercial gensets have a shutoff for low oil pressure and high coolant temp. This can be done easily with a couple of relays and a Tee for extra sensors. The oil-pressure would kill the engine so you need to hold the start button down until it builds oil pressure in this simple iteration, and replace the vacuum shut-off with a 12v solenoid which will turn the engine off when not energized.

The engine should be fairly efficent at 1800rpm, but be careful to not "lug" the engine. This engine is currently designed for automotive operation, the cooling system and lubrication system aren't set up for extended full-output at low (1800) RPMs.

As far as efficiency, much of this engine is designed to be efficient at higher RPMs, and will therefore need re-tuning to create more efficiency at low RPMs. This can include many things such as: combustion chamber design, valve timing, pre-chamber design, injection timing and injection rate, injector pop-pressure. If you want to use it for more than occasional use and are interested in improving efficiency there are probably some generator and refrigeration unit gurus who can help. At very least I would consider the oil pressure at those RPMs and water flow, might be wise to replace the oil pump with a higher-volume pump and put a smaller pulley on the water pump (or larger on the crank).

Thanks for sharing your project so far, it helps some of us live vicariously though you.

all true but maybe the scope is too much. I see 240D motors go for 100-200 on craigs pretty often. I say see how long it lasts and keep a cheap spare. I bet it will still live pretty long, much better than the Chinese motors on diesel gensets I see in the price range you will be building this.

wgreen · #37 02-26-2009, 12:23 AM

you can use the york brand a/c unit for air, check some 4x4 sites it is real common, and add a large storage tank to make up for low cfm, they can make at least 100 psi

#38 02-27-2009, 08:52 AM

Check out this youtube video, it may answer your questions

http://www.youtube.com/watch?v=1Nc7tcYn04c&NR=1

Bajaman · #39 02-27-2009, 09:34 AM

If you want to weld with it, why not get a welder with a bad engine. It would have all the controls you need, you would just have to modify them for the 240.

strelnik · #40 02-27-2009, 01:08 PM

Quote:

Originally Posted by 80's old school

I was planning on using a simple Audiovox cruise control system. Run the engine until you get 60 cycles per minute and then set the cruise. When the load changes (increases) the cruise will still keep the RPM constant to power the generator.

Yes I agree there might be other engines more suited to this but hey, I have a ragged out 240D that was just given to me. Besides.....we are all car guys or tinkerers....are'nt we?? I would be so cool to have a Mercedes diesel generator!!

The Generator heads can be purchased online ebay. Just type in generator head.

This is a great idea, but I'm not sure you even need to go this far. The generator never changes its demands on the engine, because it's stationary. It's not like a speed control that maintains speed over hills or other sources that could change thepower output of the engine at a particular rpm.. So....once the correct speed is identified to get 60 cycles, set that as the "low/minimum speed" on the idle control which would have been connected to the cable and knob on the dash. Allow for a little higher speed in case of weather changes that might affect cold starts. One bracket hooked somewhere on the frame toi hold the knob and you are done!!
No need, really, to install that PLUS a speed control.
Just index the idle speed to 60 cycles minimum generator output and you are good to go.

Speaking of diesels, I am still looking for OM 636 engines that were used in Thermo King reefer units, cement mixers, generators, boats etc. Or even cars! I still need at least one, preferably complete, preferably running, but if not, that's ok too.

PM me.

Thanks,
strelnik

Bajaman · #41 02-27-2009, 01:17 PM

Of course the load will change. The wife turns on the hair dryer and the clothes dryer, washing machine etc, all at once. The extra power has to come from somewhere, and if the rack position isn't changing, no extra fuel = no extra power. Try this go start your diesel and see if you can hold the rpm at 1800 with no load. Not very easy to do. These injection pumps are not designed for constant rpm.

The idea about adjusting the high speed governor is pretty good, but I'm not sure how precisely that 'stop' will function.

Stevo · #42 02-27-2009, 06:41 PM

Quote:

Originally Posted by strelnik

This is a great idea, but I'm not sure you even need to go this far. The generator never changes its demands on the engine,

Thanks,
strelnik

The load on a generator engine certainly does change. A governor of some sort is needed to keep the RPM constant when the demand for power changes.

lutzTD · #43 02-27-2009, 08:04 PM

Quote:

Originally Posted by 83240D

Check out this youtube video, it may answer your questions

http://www.youtube.com/watch?v=1Nc7tcYn04c&NR=1

seems a bit overkill for a 12KW genset, that should only require 18-20 HP at 1800RPM in a diesel, but it should be more resistant to load changes

Chris W. · #44 02-28-2009, 09:15 AM

On that YouTube video you can see the governor installed. You will definitely need a governor. 1800 RPM is the synchronous speed for a 60 Hz generator. (there are other synch speeds, like 3600, 900, 720, etc.) If you have a load on the engine and it slows down, the generator frequency will also slow down. The governor senses the load and keeps the speed constant, as long as the engine has sufficient power to handle the electrical load.

I think a generator in the 15 kW range would not be out of line for a 240D engine. 15 kW generators will have an efficiency of ~93% or so, give or take. Let's say 90% to be conservative. That means the engine has to produce 15/.9 = 16.67 kW x 1.34 hp/kw = 22.33 hp. Probably ok for this engine at 1800 rpm. Chances are that your electrical load will not be constant at full load either.

IMHO your main issues will be the governing thing, and as that video noted, the coupling seems to be an issue. I would think you want a reasonably flexible coupling, which will allow misalignment to some degree, and also handle the fact that the 4 cylinder engine will be producing firing pulses which tend to hammer the coupling.

Rgds,
Chris W.
'95 E300D, 283K