=jon= Posted November 12, 2020 Share Posted November 12, 2020 Hi All Trying to sort the breather setup out on my 4.6 with a Thor top end, can someone help confirm the following: Right hand (drivers) bank rocker breather has a spiral oil separator in the rocker 'spout'. Breather pipe on RHS bank goes to vacuum source after the throttle body. There's no additional PCV / restrictor in the hose. Breather pipe on the LHS bank goes straight from rocker cover to inlet pre-throttle body. Again no restrictor / PCV? Just trying to figure it all out - from my research air is drawn in through the LHS rocker, round the engine and out of the RHS, pulled by vacuum. However normally there's a PCV valve somewhere to stop it drawing air through the breathers all of the time, yet LR didn't seem to fit one from what I can see... Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 12, 2020 Share Posted November 12, 2020 There should be a nipple with a restrictor in it, screwed into the trumpet base, 4mm hole from memory? Quote Link to comment Share on other sites More sharing options...
=jon= Posted November 12, 2020 Author Share Posted November 12, 2020 Hmm - OK - the inlet on mine was originally on a 3.5 with open breathers, so where the 4.6 breather would normally connect to has been repurposed for the brake vac hose.... Typical LR, nothing is as it was from the factory It looks like the original breather -> manifold fitting is ERR6880, so you are saying that has a 4mm ID restrictor in it? Thanks! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 12, 2020 Share Posted November 12, 2020 Yes, probably : D The earlier system was very similar, but ran the 4mm restrictor inside an unequal plastic T-piece. I am sure there is a diagram somewhere, but one end goes to before throttle body, the other to one of the rocker breathers, and the other, smaller one with restrictor to the plenum. If you have this T from the earlier setup, then you could use it? Quote Link to comment Share on other sites More sharing options...
=jon= Posted November 12, 2020 Author Share Posted November 12, 2020 Found a description of the factory setup: https://workshop-manuals.com/landrover/p38/17_emission_control/description_and_operation/emission_control_land_rover_v8/page_328/ It doesn't seem to mention anything about a restrictor, and there's varying conflicting reports as to if it's needed! I probably have a spare PCV from another car kicking about somewhere, I suppose I could plumb that in if needed... Quote Link to comment Share on other sites More sharing options...
=jon= Posted November 12, 2020 Author Share Posted November 12, 2020 Found a thread with pics - looks like some of them have a restrictor disc in the rocker cover, but after some point they stopped fitting them: https://landroverforums.com/forum/discovery-ii-18/v288-fv308-pcv-install-92942/ Quote Link to comment Share on other sites More sharing options...
garrycol Posted November 13, 2020 Share Posted November 13, 2020 (edited) That last link has the arrangement. On the drivers side of the inlet crossover pipe - there are three ports one for the brakes, one for crankcase ventilation and a small vacuum port. The crankcase port connects to the top of the rocker cover and sucks the fumes out of the engine. In the pipe at the rocker cover end is this small restrictor - it slows the flow and catches the mist allowing the oil to drop back into the rocker cover. On the passenger side, a pipe goes from the rocker cover to the throttle body, and connects just before the butterfly on the airfilter side. Basically the manifold suction on the drivers side is much greater than the inlet side and it sucks air through the engine. Edited November 13, 2020 by garrycol Quote Link to comment Share on other sites More sharing options...
=jon= Posted November 13, 2020 Author Share Posted November 13, 2020 Thanks - I'll need to have a proper check of mine, it looks like there's a metal restrictor at the bottom of the rocker spout that has the spiral in: https://landroverforums.com/forum/discovery-ii-18/v288-fv308-pcv-install-92942/page5/#post691054 I plumbed mine in yesterday as per the manual and developed a really bad pick up stumble from idle, so not sure if the slight air bleed round the system is throwing it and I need to reset idle / idle enrichment or if something still isn't quite right... Quote Link to comment Share on other sites More sharing options...
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