Thread: Provent Results, and just how much better TD5 oil filters are.

The provent Field test results are finally in-press, http://dx.doi.org/10.1016/j.seppur.2012.05.023 so I can post up the results.

First of all - a HUGE THANKYOU to the 14 people who both (a)installed their provents within a reasonable timeframe and (b) provided the filters back as requested.

To the other 33 of you (excluding those who contacted me with extenuating circumstanes), I hope you feel suitably ashamed.

Anyway - on to the results.

Firstly - soot concentration.


Fig. 1 - soot concentration in oil (in Provent filter element) plotted against installed km.

For both figures, Group I and Group II are a mix of 300Tdi and 4BD1(T) engines split according to oil grade. Group III are all TD5.

After we got the filters back and measured them in our test rig, we analysed the soot content (% w/w in oil) of the filter elements using a sophisticated and accurate thermogravimetry method. The rate at which soot accumulates in the Provent should correlate roughly with the rate at which soot accumulated in your engine oil between oil changes. You can see that there is no significant difference between Tdi and isuzu engines in the rate of soot accumulation in the oil - excluding the one (Tdi) outlier - you know who you are . The TD5 data however is almost flat. Which shows that a properly functioning M+H centrifugal bypass filter (as fitted to the TD5s) can remove almost all soot from the oil (none of the isuzu engines had bypass filters fitted).

And what that means for Provent element lifespan...


Fig 2. Provent pressure drop as measured under laboratory conditions (outlier excluded here)

Groups as before. The left-most TD5 datum had not yet reached steady-state oil saturation. However you can basically see that provent elements in Td5s should last a very long time, as there is almost no pressure drop increase over time. For the others there is a higher rate of increase. The pressure relief valve in the cap of the provent will vent crankcase pressure to atmosphere when the pressure gets to 50 mBar. Though it should be noted that the flow rate under which the provents were tested in the lab is not necessarily the same as the bypass flow rates, so pressure drop will be higher if flow rate is higher. From the group I and II results, you can see that running lower viscosity oil will reduce pressure drop (and therefore prolong element life).

Originally Posted by Redback

Interesting results Ben, glad I could help.

I took the provent out before selling the car, so I have a provent here if anyone wants it free of charge of coarse.

Baz.

If you are sure you don't want it, I'd love to fit it to my TD6.

Cheers,

Fraser