WVO Designs

Mercedes Conversion

 August 2010 – I traded in my beloved 1997 Vegistroked Ford PSD with for a Toyota Camry.  Poor economy, lack of landscaping work, change in interests and impending tranny rebuild forced me to let go of the Beast.  I wanted a diesel, but the dealership had nothing for me and the offer on my truck was twice blue book thanks to a new program via Autotrader.   As I drove away in the camry,  I told myself little lies, “This is only temporary….this is the easy and responsible thing to do….”  As the weeks churned on,  the fuel bills mounted and one to many whiffs of gasoline exhaust I began to break down.  Additionally, it was hard to ignore the mounting stash of 300 gallons of clean WVO in my side yard.

November 2010 –  “Broke and desperate” is a highly functional state.  It brings out creativity and nothing else motivates quite like it.  I decided to post an add on Craigslist to trade landscape design services, clean WVO or conversion services for an old mercedes.  After a few offers of rat infested mercedes, ford fiesta’s and others, I got a hit from a fellow who had a 240D he would give me to convert his 83 300D with a salvaged greasecar kit.   2 and 1/2 days of work later, I drove away with a 1980 240D.

This car was OK.  It needed some serious TLC.  I really wanted a 300SD, something larger with more style. So,  I turned back to Craigslist(Thanks Craig, where would we be without you???)

So I parlayed the 240D into car into what was listed as a “commuter car”.   A 1979 300SD with over 250k miles on it.  With elegant, yet silly trim and fixings of a luxury relic(my favorite is the bumper guards above the bumper), I was enthralled with this vehicle.  It’s hard to imagine this puppy has been cruising around for 32 years.   Anyone with respect for tools, mechanics, engineering, etc. can get lost in marvel and wonder over this machine.   And, the deeper one goes into the understanding of its interconnected systems,  a great education and appreciation is endowed upon thou.

A day after I brought this baby home, it caught the eye another fellow mercedes enthusiast was walking his mammoth slobbery pit bull and was happy to share in my excitement and enthusiasm about the vehicle.  Welcome back to the cult.  Soon enough he ran home and sped back in his 1979 300D and we were exchanging stories and info.   He informed me there was a 79 300sd added to the local junkyard just days ago.

This is the third Mercedes Diesel I have owned.  I had an 81 300D with an early 2 tank conversion.   Additionally, I owned a 1985 300sd with a single tank conversion from Greasekings.

Alas, as old and apparently poorly maintained as this vehicle appeared, I wanted to have it inspected for safety and mechanical soundness.   Many “just drive” these cars, but I have a hard time neglecting and knowingly destroying such fine pieces of engineering.   Back to Craigslist.  I found a mobile,  “vintage Mercedes” mechanic, Derek come out and inspect the car to find issues and see if it is worth investing in. .  He rolled up in an 84 300SD.  His prognosis, was it was a fine candidate to invest in.  My favorite thing he said was, “The engine is really strong.  We’ll do a valve adj., change the filters and have this thing running at the full 120hp.”

Needed to be fixed:

Valve Adjustment

PS belt Crooked

Oil cooler lines – “These are the achilles heal of this car.  If they break, all of the oil will spill out of the car in 10 seconds and the engine will be toast”

Tie Rod ends

Center Link

Rear flex disk cracked

Motor Mounts collapsed

Upper control arm bushings -Drivers side

Tranny adjustment -shifts early

Exhaust donuts

Speedometer not working

Trunk lock actuator not working

Hard Starting

It sounds like a lot, but it could be much worse and more expensive things like interior issues, cv boots, extensive brake work, etc.  Much of this work is just to get the car “perfect”.  You can’t expect everything to work on these older mercedes and that they be perfect, unless you want to go broke.  I had a friend spend over $10,000 on repairs for his 85 300TD trying to get it “perfect”.

I had him do a valve adjustment and a compression test.   All cylinders were firing around 350 with no more than a 10% difference in compression, which is good for these older Mercedes.  Perfect compression is 400psi.   We scoped out the injectors, which didn’t look too bad according to Derek.  An upgrade to the Monark Nozzles would be something to do down the road.  Glow plugs were tested and all were working good as well.  Valves were out of adjustment.  I also changed the air filter, as that is important to have in top condition for running on WVO.

I was planning on running this on a single tank, with only a FPHE(Flat  Plate Heat Exchanger).  My oil is super clean so I don’t really need an extra filter etc.  I bought a fphe off ebay for slightly less than retail as it was second hand unused.  I also bought a used coolant heated filter(Greasecar) from someone b/c it was so cheap.  I figure it wouldn’t hurt to have this and I’ll need something to filter the veg before it goes into the lift pump.

Now it is time go get this baby running on WVO.

Now is the fun part.  Designing a system that will work for the vehicle and work for me.  After the process, I’m also going to put together a Mercedes conversion parts and procedure list for our Wiki to assist others in a conversion.

Since the engine is so strong and I’m going to invest some money and lots of time into this car(plan on keeping it),  I am going to use a dual tank design.  It pains me to be running cold veg through the injectors and engine, knowing about coking, poly and other nice things that happens when veg heats and cools frequently.  Plus some of the oil I want to use is a bit creamy at temps below 70 F.

I don’t have the money or time right now to do a full dual tank conversion so I’m going to begin by adding a couple of heating elements so I can run WVO in a single tank for the time being, until I can collect and salvage enough parts for the dual tank.  What I have so far is a 20 Plate Flate Plate Heat Exchanger and a coolant heated filter.  It is a greasecar filter which is a copper-tube coolant-wrapped a standyne filter.

I’m going to install these ASAP.  Meantime I will try a blend of ~50% diesel & ~50%Vegetable oil as I need to be burning veg.

February 6, 2011 –

I’ve been running a 2:1 blend of WVO:Diesel.  The car starts OK and runs fine.  It has a little lope at idle.  Smells great no smoke.  “My 4yr old said it smells like NY Steak.  No wait a minute, that’s vegetable oil”

Since the car is running good on veg, it is making me question why we need to heat the oil, when running extraordinary,  non-creamy, gel-free oil.  The injection pump is connected to the engine block, thus it is warm, the oil then travels through the injection.  By the time the oil gets to the injector tips, it either gives up all it’s heat when the engine is cool, or gains the intense heat that the injector are exposed to during combustion.

I’m asking myself why do I need all of the extra components to heat the oil when the engine temp will cancel out any of the heating I do.

Answers

1.   It is difficult to find and consistently produce oil that remains clear at lower ambient temps, less than ~40 degrees.

2.  Flow – A mercedes mechanic of 40+ years explained to me that fuel flow is very important for these vehicles.  Viscous oil, especially at cooler temps, will decrease fuel flow through the fuel lines and filters.

3.  Injector Spray pattern – The fuel needs to be sprayed in a fine mist in order to properly combust.  Potentially having viscous and underheated oil hitting the injector nozzles will decrease the effectiveness of the spray.  The oil may not be in the injectors long enough to heat to 170 F, especially in cold weather.

***Check out our Wiki  for Mercedes Conversion information

-Jason Jelonek

WVO Designs Product Support