Shortly after I bought my van, '88 with the 7.3IDI, I started running WMO. I was warned that it must be run through a centrifuge because filtering it won't clean it enough, that it must be pre-heated or it would die, that going over 50% WMO would kill it, that gear oil would kill it. I ignored all that and it's still running. I've run motor oil, ATF, gear oil, steering fluid, hydraulic oil, cooking oils, old gas drained from boats, etc. I try to keep brake fluid & coolant out of the oils, but some residue from drain pans makes its way in. I filter through large 1 micron absolute bag filters. The bag is above a bucket and I just pour the stuff in and let it gravity feed then pour the bucket into the tank. Speaking of filters, I think I haven't changed the van's fuel filter since I bought it. Still doing fine, but should probably consider it.

It has gotten smokier and harder to start and I think there was a definitive turning point in that but I'm not sure what it was. I ran straight WVO in it once and it overheated badly, was towing kinda heavy and the radiator was covered, not something caused by the WVO. Around that time I also had a batch of oil that had lots of gear oil and I forgot to switch to the diesel tank and ran that stuff cold during the winter. It was so thick that the fuel filter light came on and I lost power because the stuff just couldn't pump through fast enough to pull the hill I was climbing. I keep diesel in one tank and try to switch it before parking so that it flushes out the system and starts on diesel instead of whatever junk is in the WMO tank, but I often forget.

The smoking on oil is near 0 when I'm running high speeds a lot, but around town driving on pure oil makes for nasty smoke. It seems to be a cumulative thing; if I run oil for a while and switch to diesel it starts to clear up. When I go back to oil it slowly gets smokier. If I keep the oil blend to about 50% the smoking seems to stay decent. The thing is driven off & on and the blends change a lot so it's hard to really say if there's a percentage or mileage point where it starts smoking. Low speed driving even on pure diesel it smokes some because it's old & tired.

My injectors are definitely over due for replacement, they appear to be original. The pump appears to have been replaced, but don't know. My fuel usage has been around 50% WMO so even if it accelerated the wear on stuff I'm money ahead.

I'm now looking at possibly buying a '99 7.3 PS and trying to decide whether I'll run WMO in it. I probably will, but not as *****-nilly as I have in this thing.

 

I think the "success" you have received from the alternative fuels you have been running are a testiment to the quality of the parts the PO put into his engine. But it won't last for long. Without proper viscosity, temperature, and monitoring, that engine (notably the IP, injectors, rings, heads, etc) won't last long. You really should be running a separate non-ferrous fuel system with viton seals and selector valves and heat exchangers. I cannot imagine what that stuff is doing to your fuel filter and lift pump. And the WVO is likely polymerizing in your metal fuel lines and gumming up that stock selector valve.

 

Also, buy running the stock selector valve as a start-and-stop purge cycle is not recommended. You should be running at least two selector valves, so that the purge pushes back to the biofuel tank. Instead, since you are running a single stock valve, when you flip to diesel, you end up flushing all the biofuel in the filter head, injectors, IP reservior, and all the lines back to the "clean" diesel tank. Over several "purges," you will end up contaminating the one good tank you have left.

Also, the WVO sitting in the stock mild-steel tank will act as a solvent and flush all that gunk at the bottom into the fuel lines. That with the poly will likely cause fuel restrictions in the metal lines and stock selector valve.

Overall, this is just bad news running WVO without either converting it to BioD or running a heated fuel system designed to augment the viscosity of the oil to something closer to Diesel.

 

It has no mods, the PO didn't run any alternative fuels, whole fuel system is OE. Define "won't last long"; months, years, decades, centuries?

 

I think it's awesome that you're willing to come back here and give us updates. That's the critical element missing from so many alternative fuels builds. Thank you!

 

Your welcome. And to be clear, it's not a build, it's a bone stock van that I just started dumping oils into. It's got about 8 years and 20k miles of various amounts and types of oils.


My question to genscripter was kinda rhetorical since I think 8 years is pretty well past what anyone would consider "not lasting for long". I've saved enough on fuel to buy a complete motor so if it blows up tomorrow I'll be quite sad, but still money ahead. And this motor was already pretty screwed up when I bought the van, the PO used a lot of ether starting it and I'm pretty sure something's damaged, it's got lots of blowby and pretty low compression on at least one cylinder.

 

Obviously you haven't let the naysayers discourage you from saving money by recycling WMO into something useful. I have been running WMO in several engines for about as long as you have. I just run it through a spin on transfer tank filter with a diaphragm pump. My philosophy is "the filter will catch anything that can't get through the nozzles on the injectors. And if it fits through the nozzle, then it's getting incinerated during combustion and pumped right back out the tailpipe. Whether it be tiny bits of metal or whatever." What I've found is that most fuel systems with unit injectors do pretty good on it because the high pressure required for injection takes place inside the injector instead of in an injection pump. But you may have proven that theory wrong with your IDI. I have a couple 7.3 PSDs that I run 100% WMO in the summer and have to blend some in winter. My fuel filter light comes on a lot and I lose power when it's cold and the oil's too thick so I'll usually add a little diesel until I'm getting the power I want. Even then I'd say I'm still no more than 15%-20% diesel (at the most) and the rest WMO. The truck I drive the most had pretty low compression when I got it 4 years ago. I've put over 50k miles on it running WMO. It just rolled over 300k on a trip to the dunes from here in NM to Glamis, CA pulling a 24' enclosed full of toys and gear. It had a K&N cotton filter on it when I got it so the engine got dusted. I put a big paper filter on it after I got it. It actually starts better in the cold on the oil than on diesel. I have to crank it a few times and cycle the glow plugs a few times to get it started. It makes a lot of smoke both before and after it starts. With the low compression, cold weather starts on diesel just wash the cylinders and lower the compression even more. Ether has the same effect but a lot worse. But the WMO helps the seal around the pistons and keep the compression up. We do something similar with an old screening plant that has a little I4 Deere motor that is pretty low on compression. Sometimes in the winter the guys will give it too much ether and it'll just start turning over real fast because the ether washes the cylinders and it loses all it's compression. So I unscrew a little pipe plug on the intake and pour some oil in there and that gets the compression back up so it'll start. A little oil along with the ether that's already in there and we're in business. Once the pistons get hot and grow a little then the engine's making power again. I know some are saying "just fix those old engines up with some new parts" but my fuel is free (with a little effort) and my old tired engines are still goin'. So why throw money at something that's making money just the way it is?

 

WMO does trash VP44 pumps for some reason. They'll still go the distance on WMO to cover the cost of a few new pumps but it does do something to them that I haven't been able to figure out yet. I thought I had it licked once but turns out I couldn't solve the mysteries lurking inside of the VP44.

 

Did genscripter say WVO (Waste Veg Oil)? It's WMO (Waste Motor Oil), right?

 

Good job. Thanks for the update. but consider changing your fuel filter.

 

I do change it pretty regularly but the light comes on because the WMO is too thick not because the filter is dirty.

 

Yea, I have no idea where he got WVO and biofuel from my WMO post. I've run veggie oil a couple times, but normally it's WMO

 

I've thought about it a few times, but it has a sensor and warning light so I don't worry about it much. And my WMO is filtered better than pump fuel (1 micron absolute) so other than some dust getting in during handling the filter should last quite a while.