blhfla, well, here goes....
The blend is probably around 50 / 50 to start with but could easily get to close on 100% as I get to the end of the UMO stock.
Performance does not change as far as it is possible to tell. Veggie seems to have less diesel "knock" but the knock from UMO is not as pronounced as straight kerosene.
Being a tinkerer, any excuse will do to take it apart - but the plan is to oil change, decoke, overhaul at the end of each winter season.
The Listeroid runs in an acoustic hood so the air temperature around the engine is at about 70 degrees C (160 F) most of the time it is running. This means that any oil vapour not ingested through the air filter is deposited on the engine and then can polymerise and turn to resin. To clean, petrol or diesel is a good start. Internally, the coke is just scraped off with whatever can be used to scrape it from where it has deposited itself. Mostly, I use a wallpaper scraper or pallet knife.
There is no mix protocol. Whatever just gets unceremoniously dumped into the tank and the mix is whatever it turns out to be. Mixing the bulk doesn't happen intentionally either.
All fuel is passed through a 5 micron filter through gravity. Veggie is allowed to stand for at least a week before filtering. After filtering, the clear veggie goes into the bulk tank (1000 L) and the non-water gloop goes into the solid chip fat tank. The water element is discarded.
The fuel supply system is quite sophisticated (relatively speaking). The bulk liquid veggie tank is NOT heated. On exit from the bulk tank, fuel flows into a heated filter (150 C, 300 F) and then along insulated trace heated pipes to a T. At the T, valves allow either the liquid veggie oil to flow on, or instead, to feed heated chip fat (lard) through to the engine. The solid chip fat is heated in a 110 L day tank with 2 x 3 kW electric heaters which takes the fat to 80 C and then it is passed through a heated filter (150 C, 300 F) to the T. After the T, the fuel takes 5 turns of a loop around the exhaust pipe just after the exhaust manifold (about 300 C, 570 F) and then to the engine mounted fuel filter which is heated to 100 C (212 F). After the injector pump, the high pressure line is heated to 200 C (390 F) as close to the injector as possible.
I have heard people go on at length about cleaning fuels before use and if you want an engine that never wears out, then I guess it needs to be done. My philosophy is that around 99% of these engines in use around the World in very hostile conditions and using poor quality and contaminated fuel just keep on going - maybe not optimally, but they do the job required of them. (For instance, I cannot think of an occasion where I can imagine a Listeroid having an air filter installed outside of the Western World, or, for that matter, an oil change or lubrication more than once a year if it was lucky). So, if my engine wears out the fuel pump, or injector because there was too much colloidal water or acid in the fuel, then it is only a few pounds (dollars) to replace the necessary bits and everything is good for another season.
You may be able to take out the large chunks and water with a centrifuge but it will not appear to be noticeably cleaner to the eye. Carbon is colloidal in the oil and you will not spin it out.
I hope this helps.
Regards,
Ian