About Veggie Oil
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flygirl767
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About Veggie Oil
HI, Michelle here (again). This is more an 'interested ' question. My car is 1994 Xantia 1.9TD and it has a Bosch (hope that is spelt correctly) fuel thingy which I gather is OK for veggie oil. As a matter of interest, why can't the Lucas fuel thingy be used. I'm just interested, that's all. lots of love, Michelle XXX
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CitroJim
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Hi Michelle,
Good to see you on here again
The Lucas pump is a really great pump but it does not like veg oil at all on account of how the high-pressure side of the pump works.
Essentially, the rotor head or fuel distributor, which rotates to send the diesel to the right injector, just like a distridbutor in a petrol engine, runs with very close and fine clearances in the order of microns. It's a real precision piece of equipment.
For lubrication, it relies on a good flow of cool diesel fuel through it. It is actually kept lubricated by the fuel it delivers. Veg oil, especially cold veg oil, cannot flow in sufficient quantities through these very tiny clearances to keep the rotor head adequately lubricated. It then gets hot and seizes solid. In doing so, it shears a specially weakened section of its drive shaft so as to not damage the engine through cambelt damage. The pump is absolutely irrepairable if this happens.
Bosch pumps work on a slightly different principle and does not rely on close clearances and as a result, can pump even quite thick veg with no fuss.
Back in the days when Ultra Low Sulphur Diesel (ULSD) was first introduced, many older injection pumps suffered high wear and failures. This was caused by the de-sulphurisation process taking most of the natural lubricity out of the diesel; the sulphur was actually acting as a lubricant. As a result a lubricity additive was introduced to ULSD to provide pump lubricity.
Good to see you on here again
The Lucas pump is a really great pump but it does not like veg oil at all on account of how the high-pressure side of the pump works.
Essentially, the rotor head or fuel distributor, which rotates to send the diesel to the right injector, just like a distridbutor in a petrol engine, runs with very close and fine clearances in the order of microns. It's a real precision piece of equipment.
For lubrication, it relies on a good flow of cool diesel fuel through it. It is actually kept lubricated by the fuel it delivers. Veg oil, especially cold veg oil, cannot flow in sufficient quantities through these very tiny clearances to keep the rotor head adequately lubricated. It then gets hot and seizes solid. In doing so, it shears a specially weakened section of its drive shaft so as to not damage the engine through cambelt damage. The pump is absolutely irrepairable if this happens.
Bosch pumps work on a slightly different principle and does not rely on close clearances and as a result, can pump even quite thick veg with no fuss.
Back in the days when Ultra Low Sulphur Diesel (ULSD) was first introduced, many older injection pumps suffered high wear and failures. This was caused by the de-sulphurisation process taking most of the natural lubricity out of the diesel; the sulphur was actually acting as a lubricant. As a result a lubricity additive was introduced to ULSD to provide pump lubricity.
Jim
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...