What would you consider the minimum oil temp for safely running VO? I would have to guess you will say 140 since that is where the v3 comes on.
This is not quite as straight forward of an answer as one would think. But here is what we do and why:
Our system doesn't even turn on the pump until the manifold itself is 140. That doesn't mean the injectors see vegetable oil, that means the veggie pump turns on. However there is about a 20 degree lag between the manifold and the motor. So the coolant temperature
of the motor is closer to 160 which vaires based on climate and driving conditions.
Engine temperature is more important then oil temperature. ESPECIALLY with the Powerstroke. Specifically combustion and cylinder temperature. Realistically combustion temperatures are hot enough wihtin a few seconds after starting. Then a few minutes later the cylinder walls and pistons will be warm enough to promote proper ring sealing and combustion of vegetable oil. That is where the heat is being generated, the rest of the motor takes a while to absorb and distribute that heat. Ever watch a pyrometer? The engine coolant temperature does not need to be 180 or even 160 before you can see Exhaust gas temps of over 1,000 degrees.
This is why some people claim to start a cold engine on veggie. The powerstroke does it just fine,(for reasons mentioned in my writeup) especially if the glow plugs are in good working order. Within a few seconds the combustion temps are enough to sustain continued combustion without aid of glow plugs. However the injectors are still relatively cold, the spray pattern will be askew at best, the cylinder walls are still cold and so is the piston. the fuel on the cylinder walls doens't burn, some gets past the not yet sealed rings and into the ring lands, the general poor burn of the vegetable oil creates excessive coking and is very hard unlike diesel soot. As the engine warms up and the Veggie that made it into the ring lands from not being burned turns into coking that stays there. Over a period of time this coking builds up in the ring lands and will cause the rings to start binding creating either poor sealing, or excessive wear, or both and quickly compounds itself. And of course the Glow plugs become covered, etc. In my experiance though the injector spray pattern is usually not affected unless the tips are damaged. Must be something to do with 20,000psi of pressure being able to remove even the most stubborn stains
SO to sum it up so far, within the first 5 minutes there is plenty of heat in the cylinder to promote proper sealing adn combustion.
And just as a disclaimer, these times really only apply for the smaller diesel engines. Obviously a 15litre Caterpillar Engine with pistons the size of your head is going to take more time to reach safe cylinder temperatures.
Now for fuel delivery. This is the part that gets most people in trouble. So while the cylinder itself may be up to temp, most of the rest of the engine and fuel system is still cold, or just warming up. With an injection pump this becomes a big concern. Even with hot oil heated electrically the mass of the injection pump can take that heat right out again and then try to pressurize the thick oil up to 20,000 psi adn things break. Or if it doesn't break it can not pressurize the fuel enough for the engine run correctly. Then on top of that you have the delivery to the injection pump. If the oil is having a hard time supplying the lift pump with the correct pressure and volume that too can cause problems.
The VP44 is notorious for cheking out early if it can't get the fuel it needs at the correct volume supplied to it. The newer CP3 pumps have proven to be much more forgiving. The earlier P7100's are pretty stought, but just like the Mercedes lift pumps they are not trying to create over 20,000psi the shear stress is less. The Earlier Fords have been known to break IP shafts.
SO as a rule of thumb for most vehicles if you wait until the oil is 180 heated by coolant you know that the fuel system is hot, the engine is hot, hopefully the fuel passageways are hot, and there will be no issues. But, the cylinder temps were sufficient a long time ago.
Enter the Powerstroke. There is no injection pump. There are no rotating parts in the fuel system to bind or break. The fuel passes through a built in heat exchanger before it ever reaches the first active component in the fuel system. And again the cylinder temps were where they need to be within the first few minutes.
So finally the answer: 140 was the minimum safe temperature in my testing that the most difficult oil needs to be prcessed correctly. At that temperature even hydrogenated oil has reached ~90% of the lowest vicosity it wil achieve(in general- oil properties vary based on oil). That means it will filter without waxing regardless of micron size, can be pumped easily, and accurately pressure regulated. And in our system everything is standardized so that the turn on is always the same, the fuel lines are always the same length, etc. Most of the variables have been removed so we can push the envelope more.
And yet another disclaimer
- No I do not condone someone making their own system, throw it on an 85 Ford diesel and then turn it on when the exhaust temp reaches 650 degrees, or coolant hits 140. We have done a lot of extensive testing that allows us to run THIS system at THIS temperature with THIS engine in THIS vehicle.
Hope that answers your question?