It's been a downer day today. All my plans for running my boat on used veg oil have come to nothing. I brought Blackbird up the Wolverhampton 21 locks to Dixon St bridge where 'Diesel Veg' have their business, converting diesel cars and vans to run on veg oil. They are a lovely team, friendly, enthusiastic for a challenge, serious about what they do and their standard of work. But having had a really good look at my engine and how it runs and my fuel pump and calorifier, they decided the conversion just wouldn't work properly.
Here are the problems we looked at:
- We had intended using the main fuel tank for veg oil and installing a 20l extra tank for diesel to start the engine and flush through before stopping it. Because the fuel tank is below the waterline, the veg oil would be too cold, encouraging sludging. Therefore, we decided we could install a small tank for the veg oil inside the engine room and continue to use the main tank for diesel. No room in the engine hole but wall-mounted space available in the engine room itself.
- My fuel pump was a problem, as I'd known it might be. It's a Lucas CAV pump and these often break down with veg oil. It would have been better with a Bosch pump apparently. We were going to add a whole new fuel filter and lift pump to help overcome the problem.
- I was going to have a purge alarm fitted to ensure I always switched back to diesel before stopping the engine as the veg oil would thicken and cool overnight and be impossible to de-gunk in the morning.
- Filtering the waste veg oil. The oil has to be filtered down to 1 micron - much finer than my efforts to filter with muslin. Diesel Veg sell an electric filtering system but I learnt today that it's a 240V pump. The guys said I could maybe manage okay with a filter 'sock' they could provide me with, that could drain through overnight.
Each problem was sort-of being overcome until we hit the real stumbling block - temperature.
The team were looking to heat the veg oil via the calorifier pipes to lessen its viscosity as it entered the engine but the temperature just wouldn't get high enough for this to happen. Chugging along at 4 miles an hour wouldn't do it and the calorifier heats the water to about 60 degrees only. In a car, you'd be at the right temperature in a few minutes. They were reluctant to do the conversion, knowing it would be very unreliable and highly likely to break my fuel pump and I had to agree.
I'm gutted but would defintely recommend Diesel Veg for converting a car or van as they were so motivated, friendly and professional. Check out their website: http://www.dieselveg.com/