Maintenance and Operation

Written by TsTDI

There are two compression rings and one oil ring. Obviously the compression rings are on top and the oil ring is below. The oil ring is composed of three parts (2 scrapers and an expander). One scraper is better for when the piston goes down and the other scraper is better for when the piston goes up. The expander is basically a collection point that allows any oil left over to collect and fall through the bottom of the piston. The theory behind piston wall scarring is due to incomplete combustion of WVO in the startup event (signaled by smoking of the exhaust). If there is any residual WVO being attempted to combust at startup, (not enough purge times, not driving long enough on diesel after purging) droplets of WVO may come in contact with cylinder walls. Since the two compression rings have not fully expanded (not at operating temperature), residual WVO seeps below the top compression ring and will coke in a hard carbon form between them. When this happens, the hard carbon form has no where to go except up and down the piston wall and in the process scraping it and damaging the wall severely.

A great example of this is sDeck’s TDI who experienced problems with burning oil in his car.

Greasecar.com/forum

In pictures 2 and 3 you can see the WVO residue that seeped past the top compression ring (the ring is not there but you see the groove in the piston where it would be) and formed a hard carbon deposit between the first and second compression ring grooves. In the top of his thread he discuses where he may have gone wrong. I quote, "I am firmly convinced this is all due to 42K on WVO. Principle causes (aside from just running WVO) were failure to reduce OCI, too short of purges, and short shut downs on WVO.

Polymerization of Engine Oil and Preventive Methods:

Polymerization of engine oil will occur more frequently if you start your engine on trace amounts of WVO in a two tank setup. In a two-tank setup, you must always start on diesel fuel. You can see how I do not understand how the one tank system works. I don’t understand how one can change an injector nozzle so drastically to the point where adequate combustion is achieved and piston ring coking/ scaring does not occur. This is why I say, the art of the two tank setup is to start on 100% diesel fuel and to stop on 100% diesel fuel. This is what you prevent by doing this, accelerated polymerization.

Since blow-by gases is an inevitability and occurs on any combustion engine ever made due to weakening combustion piston rings over time, there will be accumulation of WVO gases in engine oil that will eventually accumulate into a possible problem. Obviously, running a kit in the correct way will slow this process down, but understand it is inevitable. THIS WILL OCCUR NO MATTER WHAT YOU DO!!!!

Problem Solution

The only way to combat this issue is to increase the frequency in which you change your engines oil. The recommended change interval is half of what you were doing before. Since the TDI engine is recommended at 10,000 miles, I would change the engine oil every 5k. I still believe that is way too long to let engine oil accumulate WVO. Obviously, how much you drive on oil would affect this. I change my oil every 3500 miles with Shell Rotella Synthetic oil 5w 40. Some may say this is overkill and unnecessary. I say no it’s completely necessary. Look at what I am preventing by doing this. I don’t have to worry about internal engine damage from occurring because I do not let WVO vapor accumulate to a problem.

Note: This oil does not meet specification requirements on a PD engine. So don’t use it…

Understand, there is no such thing as overkill maintenance when working with WVO. Would you rather change your oil a little more often or replace piston rings and bore out your engine to correct the piston wall scarring? I like simple oil changes.

Remember, go above the call of duty, you got nothing to worry about.

Operation of the Kit

Since the only kit that I believe in is the two tank setup, I will only talk about it. Operating ones kit is singly the most IMPORTANT aspect of long term success. If you thought what I have said so far is important, this discussion topic is so overlooked but ever so important to long term success. This is the "idiot factor" at its greatest. "I’ll just go one more mile before I purge….." "If I sit in WVO in traffic I won’t burn any diesel fuel…." "I’m not quite up to operating temperature but it won’t matter….." "I could burn WVO in the city, I’m at operating temperature…." "If I purge at my destination that should be an adequate purge…."

I poke fun at this but all of these will cross your mind at one point or the other. Having the opportunity to burn WVO at the flip of a switch is a powerful idea, one that should be respected and used in appropriate situations. My experience so far with WVO in our two GC converted cars has strictly kept WVO use to only on the highway. The reason for this, we are typically on cruise control and we are running our car at a consistent RPM. Although load changes (hills) and therefore timing will change, keeping our RPM consistent means the injection pump RPM is also consistent. Injection pump RPM is roughly twice that of engine RPM. So out of curiosity, I made close observations of highway driving on diesel fuel as compared to WVO. At the same RPM and similar load (same trip) my EGT gauge has showed similar EGT readings. Since this is the best indicator of combustion efficiency, I can assume that both fuels are burning similarly and therefore combustion efficiency is similar. This is a great thing. When you burn fuels on the highway, since your operating under a consistent RPM and load only changes due to terrain, your fuel efficiency is at its best. Meaning combustion efficiency is at its highest and therefore burning the least amount of fuel per mile. Why try and burn more WVO then what you have to? Burn it on the highway and enjoy the drive…

When on the highway, typically you are using the cruise control. This puts the throttle position in control of the ECU and therefore means, the ECU is only going to apply as much throttle (fuel) it needs to overcome higher loads. When you use your foot to control this, especially with my car because it is chipped and fast, it is very tempting to drop the hammer on a free fuel and waste some unsuspecting gasoline engine. Ever since my conversion, I have only done this one time. The reason why I do not do this is because remember, inherently thicker fuels involve more stress on components. There is more stress on the timing belt and more stress on the injection pump to pressurize the fuel to combust. Although my car makes the same amount of power on both fuels, I do not flirt with the fact that the stresses are higher on WVO than on diesel. I look forward to the purge 3-5 miles prior to my destination and then let her rip… There is a benefit to driving hard in this case. Purging off of oil (flipping the switch) causes two things to happen. With the flip of that switch, your injection pump is drawing its fuel source from the diesel side. The second thing is your WVO line is purged with diesel fuel. This is not necessarily the important thing…. Remember, that entire line is heated and therefore is irrelevant if WVO or diesel in this line. The purge of 30 seconds allows the return line of the injection pump ample time to send the WVO that it was not using back the return line on the WVO side, not the diesel side. This is where cross contamination can occur. 30 seconds seems to be enough time for allowing enough time for WVO to purge itself from the injection pump, to the return line and then back to the WVO tank (it took 12 seconds for diesel fuel to be seen at the WVO tank at idle when we installed the system). However, I still believe a small, irrelevant amount of WVO may still be sent back to the main tank. In this case, it is such a small amount; it will not make a difference.

After I have purged, I like to drive my car hard for 3-5 miles after purging. This allows enough time for the injection pump, the injector lines, the combustion chamber and everything that came in contact with WVO to either be purged by diesel fuel or burned off by high boost pressures, load, high engine RPM, high pump RPM and in a WOT (wide open throttle) scenario. This has ensured sure starts and smoke free starts. I have never smelled WVO out my exhaust before I shut it off. The art of a two tank is to start on 100% diesel and to stop on 100% diesel. Getting the idea???

Note: This is also when I flip the switch for my water injection for its steam cleaning capability.

Why not burn it in the city, traffic, etc… etc…

Well for one, fuel efficiency is not its best in this situation. Therefore, you are burning more WVO per mile than what you would on the highway. In the city, your engine is fluctuating RPM on a consistent basis. Not only that, load is changing on a consistent basis. I think that driving in the city on WVO could be a problem. I do not burn WVO in the city nor would I recommend in doing so. In traffic situations, I purge the second that I see them. Unless traffic is moving at a decent pace and I can keep my RPMs above 2k, I will purge off oil. The reason for this is when I have been in bumper to bumper traffic situations; I have witnessed my RPM tach fluttering at idle (50-75 RPM). This is an ever so slight increase in RPM that the average person would probably not notice but understand what is occurring in this situation. The engine is fighting to maintain a consistent RPM, meaning the ECU is adjusting fueling and timing to achieve consistency. This is not a good thing. Also, at idle, this is the most inefficient point because you’re not moving. Combustion temperatures have dropped and may have possibly dropped to a point where WVO is not obtaining enough heat to properly atomize and combust.

So when you operate the kit there are rules in which you must abide by to prevent all the problems I have discussed above.

ADHERE TO THESE RULES FOR LONG TERM SUCCESS!!!

Operating your kit should be strictly used on the highway only.

You must wait till your engine has achieved operating temperature (190 degrees)

You must wait till your WVO has achieved operating temperature (with the FPHE and HIH you don’t have to worry about this as much because it achieves adequate fuel temperature when the engine reaches operating temperature).

You must purge 3-5 miles before your destination.

You must run the crap out of your car, through the RPM band in a high load, high boost, high engine RPM and high injection pump RPM scenario. The TDI engine is powerful, enjoy the power.

If you smell WVO out your exhaust after all of these steps, YOU HAVE A PROBLEM. You are not doing something right and there is either WVO in your main diesel tank or your supply valve is stuck in the WVO position. This happened to us on our Powerstroke. Stuck valves can occur and are easily fixed; however, if left unfixed, can cause severe problems.

Such easy directions yet very little people are able to follow them. Have some respect for the entire operation and in what you’re trying to achieve. It is critical that you follow these steps to ensure a clean, sure start up the next time you start your car. It is also critical that you follow these steps to ensure all the problems I mentioned above to not occur.