Funny Kind of Dangerous Moment Today Testing Compression - PeachParts Mercedes-Benz Forum

katchung · #1 10-10-2009, 10:14 PM

I decided to do a compression test today, and being my first time I played it cautious on the first Cylinder. I ducked as my wife turned the engine over, and 4 heat shields exploded out of the injector holes straight up into the hood.

Aside from that excitement, everything went really well.

1. 375
2. 400
3. 400
4. 375
5. 360

Not so thrilled about the 5th cylinder reading, but overall I think a very positive checkup for a car with 245k miles on it.

The injectors all had carbon buildup around the nozzle tips. I suspect that's normal. It's clear I need new nozzles. I'm thinking about Monark nozzles, as I hear they are good for wvo burning.

For now, everything is put back together and functioning and nobody got hurt. Haven't found a single one of those heat shields that shot out. At the speed they came out, they could be on the moon.

G'nite.

pawoSD · #2 10-10-2009, 10:22 PM

If you are currently or are planning to run WVO, you can watch those compression numbers begin to slide.....as the rings and engine get gunked up with all the junk being fed through it. Run it on diesel. Like it was intended to be.

katchung · #3 10-10-2009, 10:58 PM

Well,

I'm ambivalent for that very reason. It's one of the reason$ I haven't pulled the trigger on a kit yet. I may just go the bio-diesel route. Though I haven't heard that a 2 tank system fed with well-filtered WVO damages rings or pistons before. I'd like to see some data on that. I'm aware that this kind of mod will reduce the value of the car, but I don't plan on ever selling it.

79Mercy · #4 10-10-2009, 11:03 PM

Those are pretty good compression numbers. But just like pawosd those compression numbers will start to go south once you start running that junk through it. I don't care how well you filter the stuff, it is still grease. That engine has covered 245,000 miles, don't cut its life short by running it on the crap.

gradyg3 · #5 10-10-2009, 11:08 PM

Have run an 85 300DT on 2-tank well sourced and filtered wvo for over 40k, and engine probably starts/runs better now than when I got the poor neglected thing. Granted, haven't done a compression test comparison but car runs great and started running WVO 2 tank system at about 182k and am at 224k now. About reducing price, not going to happen on a two-tank system, if you run a one tank bull**** system you will kill the value and car, have seen it happen. I had an 84 300TDT that I installed a two-tank system on, bought for about 3k, with about 300k on it, good condition CA car, put about 1k into it, not including the kit (mostly DYI stiff regarding rear hydraulic suspension, axles, and all around tune, fluid flushes), and drove it for a yr+ putting about 25k on it and sold it for 6.5k, you can do the math. Niche market for these vehicles and so many bleeding hearts thinking they can run WVO until they figure out you have to work a bit to do it. Go for it man, just get a reputable kit like from greasecar or one of the others that have good aluminum tanks with copper heat coils for the filter and tank. Also only source pure corn or soy oil, generally good japanese or chinese places and filter down to 1 micron after heating (hot water heaters rods or other high watt imersion heater) and settling. Remember, its a hell of a job but someone's got to do it.

Oh yeah and never leave a 1/2 horse power pump connected to a mostly full of WVO 55 gallon drum unattended, it amazing how fast they can pump when the filters have been bypassed by a broken hose.

pselaphid · #6 10-10-2009, 11:13 PM

You anti-filtered, dewatered, properly heated, two tank folks should encourage that application so that somebody will provide the conclusive data that you would like to provide in support of your opposition to the use of wvo. Here we go again...data please?

tankowner · #7 10-10-2009, 11:53 PM

Quote:

Originally Posted by katchung

Well,

I'm ambivalent for that very reason. It's one of the reason$ I haven't pulled the trigger on a kit yet. I may just go the bio-diesel route. Though I haven't heard that a 2 tank system fed with well-filtered WVO damages rings or pistons before. I'd like to see some data on that. I'm aware that this kind of mod will reduce the value of the car, but I don't plan on ever selling it.

If you have a source and some time then you should go the biodiesel route, then, as long as you are making it right, you don't have to worry about it. You proablably aren't going to find the data to tell you not to do it - nobody really wants to admit that they killed their car running WVO. I am sure there are some people out there that have filtered their WVO very well and run a good two-tank system and get away with it for many miles. In the end they might be happy with that - why not? But there's no getting around the fact that if you are running WVO you are still burning the glycerin that would be removed in biodiesel production. If you are looking for free fuel and don't mind the possibility of killing an engine in the process, that's fine. If you rely on this car though and don't have the money to throw it away if something goes wrong, then make the biodiesel and enjoy burning those hydrocarbons the way it was intended to be done.