diesel pump pressure question??

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diesel pump pressure question??

Post by ssray » Fri Dec 02, 2005 11:38 am

Anybody know what kind of pressure that the diesel pump sucks at? on my veg oil conversion i have been offered a 8psi faucet diesel pump and want to use it so that on cold days , ( i have heat furter along but not at the veg oil tank ) it will possibly be a bit thicker and i dont want to strain the orig diesel pump?

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Post by jeremy » Fri Dec 02, 2005 12:58 pm

I think the answer is 'not much' and I'd guess at 2 to 3 psi.


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Post by ssray » Fri Dec 02, 2005 1:40 pm

Thanks for that, so would a 8psi pump from the veg tank cause any probs??
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Post by DavidRutherford » Fri Dec 02, 2005 1:45 pm

over-pressureisation of the injection pump inlet will do no damage at all, as it's just a vane-type pump that you're pressurising.

One thing that I've read on SVO conversion sites is exactly this problem, that if you put a vacuum gauge on the fuel inlet pipe and watch it while changing from diesel to SVO, the suction level increases (absolute pressure drops) quite a lot, and many people are worried about doing damage to the vane pump by making it work harder.

I think your addidional pump is a wise idea.
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Post by Stewart (oily!) » Fri Dec 02, 2005 2:59 pm

something simple like a SU pump from an old mini would do the job unobtrusively, I suppose it really depends on the state of your Waste Oil if its beef dripping it will need more pushing, pulling or heat.
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Post by Linegeist » Tue Dec 06, 2005 11:10 am

I'm curious about this because I've been experimenting (very successfully) with rapeseed oil for the last few months, settling on a 70/30 svo/diesel mix as the optimum for warm weather and a 50/50 for winter use.

With the onset of Winter, I've been concerned about the effects of low temperature of the oil on the pump, so have experiments with standing a 2litre bottle outside as an observable monitor.

Interestingly, we've recently had overnight temperatures of -4c ........ and the rapeseed oil didn't even get cloudy, staying fluid and free-flowing. A very slight increase in viscosity was noticeable, but nothing to get too excercised about. Certainly the TZD's started on the button every morning on the vegoil with no untoward symptoms at all.

Just my two-pennyworth ...............