My OM616 WMO experience...

[AcIdBuRn]

Hey guys...

Before I go any further... I gave $300 for the car.. is something goes south, not taking a loss as I could scrap the car for that.

Anyways..

So I picked up a '75 240d.. unknown mileage.. 4 spd. car with quite a bit of rot but it ran. Got most of the bugs worked out and started tinkering with feeding it via waste oils.

To get started, a friend and I have been processing waste oil for fuel for several years now.. I've ran it in my 4bt Cummins repowered Tahoe and he runs it in his 7.3 IDI ford. The Cummins didn't care for it too much but the old IDI loves the stuff... actually runs better and makes more power on oil then on d2.

This isn't some flyby operation though... we batch our fuel 55 gallons at a time. This last batch was mostly aw32 hydraulic oil... ~50 gallons mixed and settled with 5 gallons of pump gas. After settling, its centrifuged for 30 hours and transferred into a holding tank which is setup with a stainless Viton sealed transfer pump, 10mic. absolute filter/water block, and a fuel nozzle.

I started out going roughly 50/50 in the main tank on the car just to see how it would go. Car ran great on it.. but after a week, I could tell the injectors were starting to coke up a bit as it was progressively taking longer to start and starting to haze.

I decided to setup a 2nd tank... found a 6.5 gallon fuel tank for a boat on CL.. $20. Plumbed it in using a greasecar 3 port solenoid valve and looped the return.

The 6.5 gallon tank now holds pump diesel with a heavy dose of dieselklean.

I cold start on the small tank and get the car up to temperature.. after a short hard run, the coking issue went away.. no more hard starting or hazing.

Once up to temp, I switched over to the main tank which is now straight W90. The car runs great on it... and literally 0 haze. The smell is definitely different.. but other then that, I'm not seeing any negative effects as of yet.

Now, I switch back to the little tank a few miles from my destination so when I shut down, its on pump diesel. Car starts like it always has and runs great so far.

From all of my time tinkering with waste oil for fuel, I've only seen problems when the engine is ran cold on the fuel. Oil needs heat to burn clean.. a cold engine, pump, injectors, combustion chamber, etc.. wont allow for a clean/complete burn which leads to coking of the injectors and/or rings. Running a 2 tank setup (which CAN be done on the cheap) is the best route to take.

Car will be paid for by tank #7

Now, I've only ran a tank and a half but so far... so good. I'll keep posting as things come up or if problems arise... I'm gonna run it 'til something major fails.

You can see part of our waste oil processor here..
Finally moved the processor... new setup.

More to come.
-Chris

[Simpler=Better]

Fancy, fancy!

Have you thought about adding a heat exchanger under the hood?

[AcIdBuRn]

Yes indeed. Strongly considering a 20 or 30 plate fphe...

I've read several articles that show cleaner burns and more power output even from pump diesel when preheated. The claims are the closer to ign. temperature, the better.

I'm not certain that the heat exchanger is required... However it certainly won't hurt.

On a side note... We have approximately $350 in our whole setup. Maybe 400... We've been able to nickle and dime it and score some great deals on parts, etc..

Would like to go with a motor driven centrifuge at some point but this works so far.

[Simpler=Better]

Founds like a decent setup.

My engine liked VO when it was preheated, you can look around for heat exchangers in the $50 range

[NZScott]

I would look into injector line heaters. Still preheat the fuel a bit, but the injector lines are where you can really pump the heat in

[AcIdBuRn]

I may do that... although at this point, its not really needed and the car wont be driven come winter.

Either way, I'll look into it.

Thanks
-Chris

[AcIdBuRn]

Got a new set of Fattywagon injector line heaters on the way... $20 shipped.. couldnt pass it up.

Car has been running good thus far... on the 3rd fill up of wmo.

I learned the hard way to ALWAYS shut down and warm up on pump diesel. I made the mistake of shutting down on oil... car sat for a few hours longer then expected and cooled off. It started ok but hazed like crazy and coked things up a bit.

It cleaned up after 20 or so miles of hard driving on d2 but still isn't perfect. I'm sure a bit more driving will clear it up though and I wont be skipping steps in the future. I need to get a quality injector cleaner to run in the d2 tank...

Anyways.. more to come.

[NZScott]

That was a good catch.

For "de-carboning", apparently water injection does wonders.

[AcIdBuRn]

I'm curious how much good water injection would do for cleaning the injectors/prechambers since the water comes directly in through the intake into the cylinder...

I suppose when the steam expands, it would get to the chambers... not sure about the injectors though.

I also think I have a little air trapped in the loop. I've looped the return back to the inlet on the lift pump. I'll probably add a couple ball valves so I can open the loop and purge the air... might get to that tonight if I have time.

I also need to check the timing chain and bump the timing up a little... I also have no idea how many miles are on this thing... seems to start quick (8-10sec glow with old style plugs) and it fires right up) so I suppose the engine is somewhat healthy.

While running, if you pull the oil fill cap, how much venting (blowby) is normal? Just checking things over and making sure its not hurt.

-Chris

[strelnik]

Originally Posted by AcIdBuRn

Yes indeed. Strongly considering a 20 or 30 plate fphe...

I've read several articles that show cleaner burns and more power output even from pump diesel when preheated. The claims are the closer to ign. temperature, the better.

I'm not certain that the heat exchanger is required... However it certainly won't hurt.

On a side note... We have approximately $350 in our whole setup. Maybe 400... We've been able to nickle and dime it and score some great deals on parts, etc..

Would like to go with a motor driven centrifuge at some point but this works so far.

I have two sizes of centrifuge.

One is small 110 VAC and about the size of a stool. It's extra, so 100.00 takes it

I have a couple setups of an air force oil separators with centrifuge, gauges etc, also 110 VAC, had put out feelers but still have one extra to sell. 500.00 takes (It's on roller and You could roll it into the pickup, whole thing weighs 525 lbs with box, etc.

PM me if interested. Several people have called me with interest, but no one has shown up with a truck and cash.

[AcIdBuRn]

PM sent.

[AcIdBuRn]

PM didnt go through... your inbox is full.

Very interested in the smaller unit. The larger sounds nice but its out of my price range. Can you send me some pics of the smaller one?

[AcIdBuRn]

Ok...

Got my line heaters in and installed. I hooked them up directly to the battery just for testing to see how they function. They don't get hot all that quickly.. but they do heat up.

I'll wait until they are installed/wired properly to say if they are worth the trouble or not... highest temp I read at the injector was 145 after they had been on and the engine was running for ~8 minutes or so. Again, perhaps I had a crappy connection so I'll wait to see how they work once wired properly.

Then I decided to give the car the ol' Italian tune up... Approximately a 7 mile stretch flat out... Ran it out to the gov. in 3rd for a bit then hit 4th and held it pegged for 5+ miles... Definitely got things toasty... floor pans were getting hot from the exhaust temps... could smell the heat coming off the exhaust...

It certainly runs smoother now... but still has the haze. I went on and ordered new heat shields and plan to service the injectors next week.

[AcIdBuRn]

Here are some pics...

Still need to silicone the length between the injectors...


Taking temp reading at the injector


And this is after a minute or so...


Keep in mind that the loose areas still need to be sealed with rtv and the wire ends were just touched to chassis ground and battery hot. Connections could have been bad.. Etc..

After about 8 minutes while running, temps were reaching close to 150 on the injector line and the wrapped portions were hot to the touch.

I'll test them out once I finish the install properly... Not overly impressed but it certainly can't hurt. Will probably order a fphe this weekend if I get a chance.

-Chris

[sloride]

Have you done a valve adjustment? The "hazing" may be from incomplete combustion from lower than needed compression. Also think about updating the series loop glow plugs to the parallel pencil ones. It may push your pay back two more tanks or so.