Td5 D2 engine - Fitting the ProVent (4)

The final stage of installing the ProVent was to connect the unit into the engine 'breather' circuit.

I thought the hardest part of the install would be to mount the ProVent body in the engine bay.

In the end, routing the hoses, connecting them together and ensuring they avoided other components proved to be the more time consuming.

I decided to remove the factory fitted 'Depression Control Valve' from the Turbo Intake hose. The ProVent unit comes complete with its own depression valve built in. In doing so, I freed up some space above the intake hose allowing the new plumbing to be better routed. 

The fitted Depression Control Valve was replaced by a 19mm plastic elbow connector that allows direct connection to the turbo intake hose as shown in the above photo.

The original factory fitted rocker cover breather hose was used in its entirety, there was no need to cut or modify it. The new section of hose simply joined onto the end via a straight plastic 19 mm connector. Doing it this way means that the original configuration can be re-installed and the ProVent removed easily should the need arise in the future.

Also, using the full length of the original fitted Rocker Cover Breather hose ensured that the routing avoided any potential heat or rubbing points.

The curve of the new hose shown above is the result of the molding with hot water. The curve is now natural and there is no tension on it. I was particularly pleased at this outcome!

Two views of the fitted connections onto the ProVent unit. The blue elbow connector was a last-minute necessary addition whose procurement caused a lot of hassle, but in the end it all worked out fine.

The blue and black connectors are also 'reducers'. This means that one end of the hose (the ProVent end) is 25MM ID and the other end where the clear hose attaches is 19mm ID.

The ProVent mounting clamp is designed to allow the body of the ProVent to be rotated horizontally to allow greater flexibility in its instillation. A last minute adjustment to that angle really helped with the routing of the inlet hose.

Also visible above is the ProVent's built-in depression control valve which is the side mounted circular projection near where the blue hose attaches. In addition to this control valve, the ProVent unit also has a built-in safety valve in the lid section that will open if the engine blow-by gas pressure gets too high.

The final connection was on the base of the ProVent where the oil drain-off outlet is located. It is a 13mm connection and I simply ran a suitable length of plastic tube vertically downward and secured it to the outside of the chassis rail. 

The end of this hose needs to be 'capped' as leaving it open to the atmosphere will disturb the airflow balance through the unit. Options are to fit a one-way valve/stopcock drain to its end or fabricate a bung.

I choose the cheaper option and used a spare piece of wooden dowel that was a nice tight fit in the open end of the hose. The image above was taken from underneath HX and shows a section of the front nearside chassis rail and axle sway arm. I feel the tube needs to be trimmed shorter to avoid grounding issues. Trimming it back to the chassis rail would be best.

Research online points to low levels of seperated oil being emitted from the drain and having a transparent hose will allow a visual inspection of any recovered oil building up in there over time.

The ProVent manufacturers are 'Mann Hummel' and they make available lots of information and specifications about the ProVent range via their website. It is required reading and even mentions the option of plumbing the drain back into the engine sump to ensure total recovery of oil from the by-pass gasses....

Here are the final costs...!! (some clips,hose,straight reducer and straight connector remain surplus)

ProVent 200 - £98.50 - 'MFE Wrexham' (E-bay)

Silicone Hoses  -  'Demon Motorsport' (E-bay)

All are 'reducers' 25mm to 19mm

Straight x2  -  £10.98

90° elbow  x1  -  £7.19

Plastic Connectors  -  'Adv Fluid Sol' (E-bay)

19mm straight x3  -  £4.74

19mm elbow x2  -  £2.52

Plastic Hose  -  'Mirfield' cowboys via (E-bay)

19mm x1mtr  -  £4.22

13mm X 500mm  -  £2.52  

Hose clips  -  'B+M'

assorted sizes x8  -  £2.99.

TOTAL  -  £134.60

ProVent 200 installed on the Td5 Discovery.