seems to be 80-90
I have an adjustable relief, but it can't keep up with the pump if something blocks off the fuges. And then if I foolishly flip the bypass selection valve the wrong way the relief is before that so the fuge doesn't stand a chance. I have only deformed them once after I added the adjustable relief.
On the fuel I'm running now, it is thick, and I am very sure that if these cars didn't have a heat exchanger before the filter it wouldn't work. I'm not running it pure in the truck (pure coincidental both tanks were filled with diesel by a friend), so I cant speak for it. Once I run the tanks dry i will fill them with pure as well. The cars will not act right til the engine is able to heat the incoming fuel. I typically fill up in the morning, and leave it idling while doing so. On the days we just crank and go we get a half mile down the road and start starving for fuel. Both cars do it, little blue didn't stop starving for fuel until I was 4 miles down the road and the temp hand nearing normal this morning. They are drivable, but you have to be easy and slow til they warm up. Don't have a clue what the mic rating on the stock filters are on the cars, but they have a lot less surface area than the filter on my truck does. They also have 1/4" OD fuel lines under the hood, I'm sure that doesn't help either.
Another thing to mention is I am not 100 percent the fuel is pure gear oil. We originally thought it was heavy weight hydraulic possibly 50W or 60W, but when comparing drip rates/viscosity to 80-90 it's very similar, and the smell/look is too. When the oil is cold it works my pump pretty hard, and the pressure on the exhaust of the pump runs about 60PSI with everything open. In other words just the viscosity alone cause the outlet side of the pump to run 60PSI. Once the oil is up to 150 200 degrees it is pretty thin, and the open head pressure is around 5PSI. The hotter it gets the thinner it gets which makes me assume it does not have any viscosity modifiers as any engine oil would.
One thing to note, this batch processing right now I would have sworn it was almost dry, I pulled from the top 6 inches of a 275gal tote that was filled up to the neck. That tote has been sitting unmolested for 3 months. It boiled for a couple hours last night, and has been boiling for 4 hours today. It is starting to slow down, I figure another hour it'll be dry. Gear oil holds water extremely well from what i can tell. The oil was severely water contaminated when I picked it up, and a 2" trash pump was used to move it, water and all. The free water was drained off. This is water held in solution or emulsion. For about 2 hours it was a hard steady rolling boil with steam pouring off so thick it would reach the roof of the barn before it dispersed. Considering that, it may well explain the troubles people have had with getting it to work out. I don't know how well dissolved water can pass a water block filter. As far as i know I am the only one that heats my batches to well above boiling temperatures, I do it for this very reason. The reason I started doing it was because I accidentally left my heater on one day and the oil got so hot it started to smoke the paint and oil residue on the processing drum, as well as melting plastic stuff inside the drum including the insulator formed onto the end of the heating element. When I ran that batch, it was the smoothest running easiest cranking batch of any previous batch I had run. From that point forward, I have super heated all my batches at some point, usually before it goes through the fuges.