240D engine to be used for a Generator (info needed)
 

I live on the Gulf coast and have been wanting to build a large standby generator. Now I have located where I can get 15,20,or 25 KW heads.

My question is, what would be the best way to couple the engine to the generator head? I will mount the engine, radiator, fuel tank, and generator head on a skid. I am trying to create the most cost effective way to couple the two.

BTW, the engine is an automatic transmission engine.

is the stock trans too much of a loss for you? Determine the most optimal RPM range based off someone's dyno sheet and find the corresponding gear through trial runs kW output.

I don't mean to dampen your enthusiasm, but vehicle engines are not the best type of engine for this! They are meant to provide varying RPM's and power levels and will not hold one constant RPM and be governed well connected to a GenSet. I would seriously look into a Perkins, Yanmar or Hatz. I would look into a Hatz. There are really durable air cooled diesels and this company has been around since the turn of the last century! They make excellent diesels for industrial power service and this is what you are trying to do. I honestly do not think that a 240D engine will do the trick for you if it came out of a car.

What you need is something in the 30 to 42 horsepower range. If you have the time, I would also recommend a Listeroid engine for your project! They are much better on fuel and easy to start by hand! There have been successful Listeroid homemade gensets that deliver amazing results for very little fuel and these are designed to run for long periods at a time and handle varying loads better than a lot of others and no governor is necessary because of their design.

Try this link for some ideas: http://www.listeroid.com/

This link is to a great site called UtterPower and their CD on Lister Engines is worth the $20 bucks alone for offering real practical guidance for the Home Do it your selfer who wants to build a genset. This site and the links at both are worth a read!

http://www.utterpower.com/ Good luck and let us know hiow it turns out!

That Listeroid would be the "ideal" stationery gen set, but as a second option I would look for a marine unit out of a fish boat or yacht, someone thats up grading for more KW. One shouldn't be hard to find around a large port.

what is your source for generator heads?, and are they 1800 rpms? I have several "Thermo-King" engines, that did have generaters on them and am looking for a 15kw head.

Although there are other engines built for generating, I see no real reason that the 240d engine would be not suited, other then not having a governer. You really would need to adapt one to the engine. But other then that you are well within the rated power, and rated duty. I can understand using what one has on hand if it will work, rather then looking for the "right" engine. Depending on the rpm's of the generater a direct drive without the transmission would be best. Do stay away from belt drives, unless side load from the belts are taken by bearings other then the engine. In other words use a short piece of drive shaft to a pulley with a bearing on each side of the pulley to take the load.

It seems everyone except 47Dodge missed this crucial statement.

As long as this isn't going to be providing energy for a small village, I see no reason to believe that the costs incurred by fabbing some 'perfect' transmission will become overshadowed by the net difference in fuel costs to operate on a lesser transmission such as the stock one you already have.

I would be very surprised if a simple collection of rubber intermediaries and a shaft (as mentioned) could not replace the entire trans.

The transmission can't be used without a way to compensate for the slip in the torque converter, which would really complicate the governor. You will need a direct-drive.

1800rpm should be fine for that engine.

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

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.

Also on a 1977 240D....what horsepower do you think this engine will make at 1800 RPM directly coupled? Do you think it is possible to make 25 HP at such a low RPM?

Does anyone have a chart showing the HP torque curve vs. RPM???

The question about the engine speed and horsepower is a good one. I would think a generator that runs around 3600 rpm would be a better match for the Mercedes engine as their maximum horsepower is rated at high rpms (I think 4000 to 5000). You could use a 2:1 speed reducer to run the engine rpms higher, such as a pair of v-belt pulleys. Pulleys would also let you tailor the speed just by changing pulley sizes. But you also may not need the full HP of the engine, so running at lower rpm's would save fuel.

As for attaching it to the generator, you could direct couple it to the generator using a Lovejoy type flexible coupler, but alignment would be more critical. A better option would be to use a short drive shaft with U-joints between the engine and generator, or engine and v-belt pulley for speed reduction. If you use v-belts, you could likely mount the pulley directly to the flywheel. To mount to the engine, I would use a manual transmission flywheel, onto which you can mount an adapter plate for the drive shaft or pulley. Also, I think the manual tranny flywheel would be needed to balance the engine and for inertia as you would not be using the torque convertor, which does that function for automatics. I would not use the flex plate at all as it is just not rigid enough for what you want to do.

For the governor, I would buy a mechanically belt driven unit and install it in place of the alternator. These governors come in fixed speed or variable speed and are designed for power units and generators. You would just need to fabricate a linkage. They are also full-proof. You will not need your alternator since the diesel only needs the battery for starting and all gauges are positive on that engine.

You should also consider installing a safety gauge system. These types of gauges will shut the engine down if it overheats or looses oil pressure. Murphy is one maker of these type gauges.

For maximum efficiency, you need to target the torque peak of the engine in question. Like others have said, the easiest solution would be to get an IP with a variable speed governor.

Other possibilities would be: pulley driven governors on old tractors, also I thought of using the controller from a junk portable welder.

As far as coupling goes, you definitely want a direct drive. A manual transmission behind it would be nice if you want gear reduction 3rd is something like 1.4:1 so you could operate the engine at ~2500 which is close to the torque peak.

This is great info. I will be going to get my "freebie" 240D probably next weekend. I will be pulling the engine out of it shortly after that.

post pics, I am also interested in fabbing one of these some day. those Listers look scarey to me.

If using a cruise system to adapt for the governor.....I don't think that would work very smoothly, because these engines tend to "Ramp up" really fast once they're a bit past idle, so it would constantly be overcompensating and making huge adjustments from idle to power to try and keep it at that speed, especially when there's not much of a load on the genset.....if there was a load it probably could do it pretty smoothly.....otherwise, I bet it'd blow out the cruse actuator in short order. In addition, in case the cruise system failed, I'd install some sort of tach/overspeed monitor that shuts down the engine if it went over a certain rpms.

If I ever try to build myself a gen set I am going to go for an aircooled diesel or a MB thermoking motor like has been mentioned before. We even have a huge thermoking location not that far from us....

I just want to hook my DC welder to my spare 240 engine.... So I am hoping for pictures and stock numbers for the connection from the ( standard) flywheel to the welder.
Also, any suggestions for a method of ramping up the rpm when starting to weld... foot control, RC ?

I will definitely post pictures when I start to build it. I have to get the car here first and make sure I can get it to run right. The car has not been driven since 1996. He said it was running perfect when he parked it. He said he quit driving it because reverse went out in the tranny.

OK, as far as the hub to hook up the gen. I think (at least the plan for now) I will get a piece of plate probably 3/4 thick and cut it round about the size of the stock toprque converter. I want the plate heavy to mimic the weight of the stock converter. Then I will drill a hole in the middle of the plate just large enough to stick a shaft through it. I will then weld the shaft to the plate. I will then chuck up the shaft/plate assembly in a metal lathe (holding the shaft) and trim cut the plate until everything is concentric. I will then locate holes in the plate to mate to the stock flexplate of the engine. The bolt it up, using probably 1/2 spacers between my new plate and the flexplate. I will then use either a woods or a lovejoy coupling to connect the gen head.

When I talked to the guy selling the gen heads, he said several of the units he sold were to be hooked up to Mercedes diesel engines. Funny, this is prolly the largest gathering of diesel merc fans at one time and you just don't hear about this being done much!!

I will keep you all posted!

Also, again, any ideas what the 240 will make HP @ 1800 RPM??? I am hoping it will at least make 25HP. At first I was gonna use a 300d turbo engine for this project because I have a line on prolly getting another diesel car for free!! I know the 300 would make the HP. I just think I will use that engine for some other project.

I'll say it again, I think it is a bad idea to use the flex plate. They don't call it a "flex" plate for nothing. Remember, the torque convertor is supported partially by the transmission input shaft, not totally by the flex plate. And the heavier you make the plate, the more the overhung load, and the more the flex plate would flex. You don't want that thing flexing at 2000 to 4000 rpm. Find a manual transmission flywheel.

Using the flexplate will not hurt anything. It will, however, be far too light to keep a steady RPM with a generator. Remember that the torque converter is 3/4 of the rotating mass between the engine and transmission. You need mass to keep RPMs stable and that means using the heavier manual flywheel.

I was planning on using a plate about 3/4 to 1 inch thick to keep rotating mass up. Also you will be turning a quite large (rotor?) in the generator as well.

I should be going to pick up the little 240D this coming weekend. First line of work will be to get the engine running well in the car.

I don't know anything about the injection pumps / governors but isn't there a test in the manual to test the governor on the pump (if that's where it is) - the wide open throttle test or something shouldn't exceed X rpms? So, seems like you could just screw down on the governor and lock open the throttle all the way to keep it at whatever RPM you decide you want.

[quote=kalpol;2112231]I don't know anything about the injection pumps / governors but isn't there a test in the manual to test the governor on the pump (if that's where it is) - the wide open throttle test or something shouldn't exceed X rpms? So, seems like you could just screw down on the governor and lock open the throttle all the way to keep it at whatever RPM you decide you want.[/quot

That would be sweet if you could do that!!! Somehow I just don't think it will be that simple.

Its a fantastic idea, I don't see a reason why it couldn't work.

http://www.peachparts.com/shopforum/1772106-post20.html

240 should do the job very well. I would not consider an air cooled due to excessive noise.

More info on generator heads can be sourced from a vendor Dick Wright of Wrico Generators in Oregon. I have one of his with a 4 cyl Kuboto.

Good Luck

Thanks....I will check them out! I think the 240 will work nice especially since I will only turn it 1800 RPM.

BTW Cessna 5354......what do you fly? I used to fly a 172P.

80's old school,

I don't have hp/torque curves for the 240D, but do have them for the 220D. A 240D is a bored out 220D, and peak torque is 2400rpm for the 220D. These engines like to run fast, meaning you'll coke or produce carbon deposits if you load the engine at lower rpms. My "educated" guess would be about 3000-3500rpm for a generator application that would be a decent balance between a happy engine and a happy fuel budget. "Redline" is 4350rpm on the 220D.

If it was me then I'd find a clutch from a manual transmission then mount a shaft with a HEAVY balanced flywheel behind the clutch, then double belt to the generator, using the sheaves (pulleys) to match engine and generator rpm. HEAVY means at least 200lb, the more the merrier. The clutch makes engine starts easy, and good bearings and substantial safety cage should be obvious requirements.

Governing a generator is an interesting issue. Most of the time you're producing a fraction of rated output. Then a motor kicks on and you need a big AND fast reaction from the governor, up and back down as the motor spools up. A car cruise control should react fast enough (with a big flywheel) but I wonder if it can dig deep enough. I'd think it's worth a try, but wouldn't test while running expensive electronic loads like a computer - they can't handle big electrical frequency swings. If the car cruise control doesn't work then you can fit a mechanical governor from a scrapped farm or industrial engine - you get more dig. Look for the working end that mounts to the front of the engine crankshaft, and keep in mind a governor for a 1600rpm engine may not last at 3000rpm. Mounting the working end on the generator sheave shaft is another option - slower rpms there.

Plugging in a battery charger helps stabilize the electrical load on the generator, and eliminates the need for an engine alternator.

You're going to drink fuel, but if you're going this route then you probably don't want or care about idling the engine with no electrical load. That gets complex and expensive real quick.

Keep us posted....

There are "universal" governors available that are belt run. These aren't cheap new, but do show up on the surplus market as they easily outlast the engine they are attached to.

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.

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.

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.

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!!!

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.

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 :D

Check out this youtube video, it may answer your questions

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

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.

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

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.

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.

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

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