More Mercedes Engines!

[WStayton]

Hi, Guys!

  I'm not sure what's going on, but I pulled my hair out for a year looking for a reasonably priced, reasonably good condition OM616 engine to purchase.

  Ultimately I found two of them, one only one state away, in Massachusettes and one four states away in Maine.  They were pretty cheap - $200 for the MA one and $300 for the ME one which was/is a marine version.

  Now, all of a sudden, they are cropping up everywhere - in the last week two have materialized within 75 miles of me - both about 100,000  miles and $300 (asking) for one and $400 (asking) for the other.  Both of these are post 1979 engines with the improved combustion sytem.

  So, what I was wondering, should I pick up yet ANOTHER engine?

  I am pretty sure that the two I have will satisfy my requirements for my generator projsect, so I'm not sure what I would do with another one - they are sorta large to use for a paper-weight!  <grin>

  But I can just hear them, both calling to me:  "Wayne, come and get me!". <sick smile>

   So, should I buy yet another, un-needed, Mercedes engine, or should I just make an appointment with the psychiatrist?  <smile>

Regardz,

Wayne Stayton

[Lloyd]

Hi, Guys!

  I'm not sure what's going on, but I pulled my hair out for a year looking for a reasonably priced, reasonably good condition OM616 engine to purchase.

  But I can just hear them, both calling to me:  "Wayne, come and get me!". <sick smile>

   So, should I buy yet another, un-needed, Mercedes engine, or should I just make an appointment with the psychiatrist?  <smile>

Regardz,

Wayne Stayton

GRIN

Just buy the go***7am things, and then never woory about parts except for gasKets.

it''l be a good invest ment i'm shoor.

hehehehehehehhe

lloyd

[mobile_bob]

you are screwed!
you got the dreaded cast  iron disease for which there is to be no recovery.

try to deny it?  and spend sleepless nights wondering if you should have bought them!

just try it!

bob g

[BioHazard]

There is no such thing as too many engines. My psychiatrist said so.   I've got more engines than I probably even remember, some I have never heard run and probably never will.

But you really picked the wrong place to ask. This is like asking an alcoholic if you should have another drink.

[WStayton]

BioHazard:

  You said:  " This is like asking an alcoholic if you should have another drink."

  But who know more about anther drink (or engine) than an alcoholic (or engine "collector")?  <grin>


   I want to thank everyone who has replied . . . not that you have solved my problem, but you HAVE made me feel better about it! <smile>

Regardz,

Wayne Stayton

[BioHazard]

Let me just put it this way:

I only have one instruction given to my family members in the event of my death. Bury me in my truck. (the one with the big block) And I want an inline six as a headstone.

I wonder if they will let me do it with a full tank of gas?  

[Tom Reed]

If there will be minimal affect of your matrimonial harmony, BUY IT!!!

[BioHazard]

The fact is, the only way to keep your equipment always working properly is to have a perfectly good spare you're not using. I think it's a law of physics or something. As soon as someone else buys that cheap engine you saw all the sudden you need a crankshaft and there won't be any for sale.

[WStayton]

Hi Guys!

  BioHazard brings up, at least the edges, of another issue I'm starting to wrestle with . . .

  I have ONE (Well, at least, so far!  <grin>) spare engine, and I was planning to pull that down into pieces when I overhauled the "main" engine for gnerator use.

  How, exactly, do you think that I should inventory/store/warehouse the pieces/parts of the "extra" engine?

  I think it goes with out saying that I should leave it in pieces and NOT re-assemble it, because in anything less than a highspeed, no load, WOT run-away, I just don't see myself swapping out a WHOLE engine.  BUT, there are a few problems:  The Mercedes OM616 engine underwent a redesign in 1977, partly because they developed a better combusiton chamber design and partly to beat the Europen tax boys who imposed a (larger?) tax on engines over 2.4 liters.  So, the original OM616 was of 91 mm bore for a total displacement of 2404 cc, and the "new"/redesigned OM616 engine was of 90.0 mm bore and a total displacement f 2399 cc, nicely beating out the 2.4 liter limit!  The stroke and the crankshaft were exactly the same - well, almost, they did fiddle around putting in some thrust washers here and there over the years, so any crankshaft will work in any engine but different crankshafts require a diferent/specific mix of thrust washers.  I'm not sure, yet, what is required to put my "spare" crankshaft in my "main" engine.

  Oh, and for the record, my spare engine is 1981 (i.e. "new") vintage with the 2399 displacement.

  The valves were exactly the same for the entire 14 year run of the engine, so any exhaust/intake valve will work in any engine.  Also, the heads, though different, are interchangeable.

  To fourther complicate things, my "main" engine is an ex-marine engine which has the new head design and the old 2404 block!  Confused yet?

  So, what I THINK I am going to do is:

1)  Overhaul the spare head and reassemble it, right down to the overhead cam shaft, and if I have valve problems, in the future, just swap out the whole head and then work on the "tired" head at my leasure.  Valve problems are the most likely probelm that I forsee, and they are by no means common in OM616 engines, so I'm probably "prepping" for a VERY unlikely problem.

2)  Pull the crankshaft out of the block and have it checked and reground, if necessary, and then, put it aside, along with a set of new, appropriatly sized bearings - for future use, if needed.

3)  Check the spare block for dimensions and get it bored/honed as needed and then put it aside along with a set of appropriatly sized pistons/rings for future use, if needed.

4) Bag up - LABELED - all of the bits and pieces that are part and parcel of the assembly, sorted by particular job - i.e. valve train gears, chains, etc., etc. in one industrial ziplock bag, oil pumpr drive and pump and assorted bits/pieces in another industrial zip lock, etc., etc.

  One thing I have wrestled with is how to keep all of the various parts with non painted/treated surfaces from rusting here in the more than a little drippy north-east.  My plan is to coat every suface with a liberal coating of axle grease and then wrap it in an oiled rag if small, followed by a wraping with industral "saran" wrap such as is used to palletize things for shipping and then, carefully, salt (figuratively speaking!) it away in the back corner of the workshop in a fold-top plastic shipping box, if small, and just sitting on a pallet if large (think cylinder head, block assy).  Anybody see any problems with this procedure???

  What I envision doing is going to cost on the order of $1,000 and I wrestled with if it was really worth it to do all of the work in advance, before it is needed, if ever.  I have sort of convinced myself that since the generator is necessary for things to function, more than minimally, in the winter time, and that I want to be prepared if there is a "significant" electrical outage (think EMP/Solar-flare), that the $1,000 was really just another insurance premium against the unthinkable.

  Of course, while the forgoing is going on, I will also be overhauling the main engine to run the generator.

  Comments, critiques, criticisms?  Comment is hereby solicited! <grin>

Regardz,

Wayne Stayton

[LowGear]

So Wayne,

Which years are the magic years and engines we Merc WannaBees should be watching for? 

For transportation considerations should we disregard the Turbo pull or hold out for it?

I see five cylinder units?

Casey

Oh, I leave them in as few pieces as possible.  Just easier to inventory.

[RJ]

Might I ask why that engine? Seems there are simpler engines with gov setups that wold be simpler to use for a gen set

[WStayton]

LowGear:

  I am most conversant in the four cylinder version so I'll speak to that first.  The big change over for the OM616 came in late 1997 - so the very last 1997 models produced had the improved combustion system and were rated at 4400 rpm and 72 HP, the "old" model were rated at 4200 rpm and produced 64 HP.  I guess if your going to push around four and half thousand pounds of car, you need to rev the engine's to those rpm's just not to be a traffic hazard.  The tach for the marine version of the samw engine only goes to 3500 rom and the last 200 rpm is redlined - though swinging a fair sized prop, I doubt that it would get to 3500 unless you dropped it, while running, out of an airplane.

  The five cylinder naturally aspirated versions of the OM617 engine were just, essentially, an OM616 with one more cylinder added on.  Same bore, same stroke, same injectors, and same crappy power output - exactly 80 HP at 4200 rpm!!!  Which is exactly the same 16 HP per cylinder that the four cylinder OM616 gives you at 4200 rpm.

   The five cylinder naturally aspirated engine also received the head redesign that the four cylinder engine got at about a year later than the four cylinder version and the "improved" version was rated at 88 HP at 4400 rpm.

  The turbo engine was a slightly different can of worms.  It didn't debut until 1981, so when it first made its appearance, it came with all the combustion chamber mods already.  It is a slightly different combustion chamber, though - slightly c/c bigger bore and different injector that the non-turbo engines.

  The turbo five cylinder was rated at 125 HP at 4400 rpm, so it had substantially more horsepower than the non-turbo engines on a per cylinder basis.  The valves were different - sodium filled exhaust and bigger intake and the engine utilizes a set of "squirters" to squirt engine oil at the bottom of the pistons to keep them from melting - something that is, apparently, not required for non turbo engines - though if I coulod lay my hand on a set of them (only available inEurope for four cylinder - rats!), I'd grab them!  Apparently it doesn't take much machining to tap into the oil gallery and install them in any block!

  The big problem with all of these engine, for use on a generator, is that the torque peak occurs at 2400 rpm - 600 rpm above where you want for your ST generator to run direct-coupled.  Though Mercedes DID market them for/in generators for about ten years - though not many were sold, since they were a very high dollar item and most penny-pinchers opted for something less expensive and more throw-away!

  I'm sticking a transmissioon in the chain for mine, so if I really need 24 kW, I can shift into 3rd and run the engine at 2550 and make about 30 kW, which will not be a tremendous help for my 24 kW generator.  My assessment is that I can get about 22 kW at 1800 rpm with the "pedal-to-the-metal" and something that I think is ill advised, since running at 100% of available horsepower does, substantially, shorten your engine life.  I feel that 20 kW should be my normal maximum, in fourth (straight thru, 1:1) and I will have to stop and shift into 3rd if more is required.

  Which one you should pick, sort of depend on how much horse power you need.  If you need 120 HP, no way, no how, are you going to get it with a four banger - a least from Mercedes!

  I should add that about 1% of the OM616 4 cylinder units built make it to 500,000 km without having the head removed. - A very few of the five cylinder naturally aspirated engines make it - maybe  half as many as the four bangers and NONE of the turbo engines had made it to 500,000 km with out having the head removed for something - the something usually being valves - when last I checked.

  Of course if you put a turbo engine on a generator and only use 75% of the HP available at 1800 rpm, something like 28 kW, YMMV! <grin>  It seems to be with automobiles, if the power is availble, everybody uses it! 

About having things in big pieces - I sort of figured that I should have the tear-down/overhaul all done before hand, so when I DO need a part, it is readily available and I don't have to sit, generator-less for four to six weeks while I wait for pieces/parts to come in, some shop to hone/bore the cylinders, etc., etc.  I further figured, that if I was going to change pieces/parts and not engines, I should have them in the condition that I wanted for instant (well, my instant is about ten days!  <grin>) and not have to spend time assembling the overhauled parts and then disassembling them to get what I want.  Of course, I am SCREWED if I need to change out the whole engine due to a catastrophy!!!!  I can't imagine getting all the parts back together into and engine in less than a week of long days to do the job - so there goes my quick turn around!!!  <grin>  All of which brings me, sort of, back to the original subject of this post - maybe I DO need another engine, so I can have a set of pieces/parts AND a complete engine sitting waiting!  <smile>


RJ:

   Yes, there are easier ways to go, but the Mercede OM616 four banger has a well deserved reputation for longevity, with about 1% of them making it to 500,000 km without having the head off!!!  I defy you to show me any engine, any where, that does that, except for, maybe, a real Lister, which is too small for my purposes.

   I wrestled with how to hook up a fly-ball governor to the OM616, and spent endless hours thinking of ways to make it NOT a mechanical monstrosity and then I stumbled across an electronic (as in digital) governor made for Generac generators, in about this size range, that used the AC frequency to sense 60 Hz as a set point and had an all electric actuator, so no vacuum necessary, and all available for about $200 including shipping!!!  I was overjoyed and promptly ordered one each of the computer and the actuator, and have it setting waiting for generator assembly!

  So, I seem to have gotten the BEST engine and an acceptable means for RPM control, and all for a very reasonable price!! <grin>

  I AM tight with a nickel, by the way - you can hear the buffalo groan from being pinched, before I let loose of him!  <smile>

  So there you have the Mercedes OM616/617 story and the governor story - two for the price of one!

Regardz,

Wayne Stayton

[BioHazard]

When saving spares I like to keep complete running engines ready to go. Often one of the easiest fixes is to simply unbolt the engine and put in another. I keep a 350 on a stand in my shop ready to go for my truck. Trying to build a complete spare for my boat so as not to delay summer fun. If I take an engine apart I'm sure to lose half of it.

That said, one spare isn't usually enough for me either..............

[rcavictim]

Wayne,

AFAIAC if you are off-grid and relying on a diesel generator then you absolutely must have a second, fully turn key ready diesel genset installed and available at the flick of a switch or two.

I have a 9 kW, 460 volt, 3-phase powered by a 1.5L 1980 VW Rabbit diesel and a 12 kW, 460 volt, 3-phase powered by a new Changfa 1115.  I have a spare VW engine available to drop in but it requires taking out of the car first.  It will be quite an upgrade since it is a newer 1992 engine of 1.6L with a turbo which has low miles since a rebuild.  That shud get me into 12-15 kW on tap after the swap.

In my case I also consider that when only light loads are required I don't want to run one of the the 'big' generators since that wastes fuel and isn't good for them so I have set myself up also with a prime and standby small diesel gensets in the 2-3 kW single phase class.

Just in case I start having a really bad day I have a 6 kW single phase PJ-1, Petter plant installed and turnkey ready to feed the house.  It is an oil consumer and smoker but runs well.  I need to deal with this someday.

I have hand built all of these power plants over the past decade as part of my plan to go off grid without having much money to invest.  Much time invested and still not using the systems as intended except that the VW gets regular use powering the shop machinery or the house when there is a utility outage.

Two wind turbines are also in the picture for my off-grid system.  Nearing completion of the main wind turbine now.  The second will be a modest 2 kW class machine which will take little time to build and which will be a very important back-up.  Where I live there is no way I'll be able to do any repairs on a failed wind turbine during the winter.

[deeiche]

Wayne,
SNIP

I have a 9 kW, 460 volt, 3-phase powered by a 1.5L 1980 VW Rabbit diesel and a 12 kW, 460 volt, 3-phase powered by a new Changfa 1115.  I have a spare VW engine available to drop in but it requires taking out of the car first.  It will be quite an upgrade since it is a newer 1992 engine of 1.6L with a turbo which has low miles since a rebuild.  That should get me into 12-15 kW on tap after the swap.

SNIP

Are you driving induction motor as generator?