V8 Breathers ?

[zim]

Morning,

Just a little question...

On a rover v8 the o/s rocker cover breather goes through a flame trap and back into the inlet, with a small T piece in line which is suction from inside the plenum.

I've read that this is to get air to circulate around the engine so as to not get a build up of gases.

Is this all necessary ? Or can i just vent my rocker covers to a catch tank ? I'm thinking along the lines of if i roll it, i don't want all the oil draining into the air pipes.

Would changing the breather system change my MAP and so have an influence on the base megasquirt map that mr HFH has sent moi ?

Attached is a picture stolen from nige's ms thread that i've scribbled on showing a conventional breather system.

Cheers

G

[FridgeFreezer]

I'd be more worried about the air bleed "mushroom" at the back of the rocker cover when deep wading.

[zim]

Sorry, which part do you mean ?

I'm using a pair of chrome blinged covers not the normal efi ones, with the only ports being a breather on each and a filler. Only because they have a tiny bit more space letting me fit my alternator nice n snug

[Bull Bar Cowboy]

Sorry, which part do you mean ?

I'm using a pair of chrome blinged covers not the normal efi ones, with the only ports being a breather on each and a filler. Only because they have a tiny bit more space letting me fit my alternator nice n snug

On the rear of the N/S rocker cover is a small mushroom cap that is the air inlet to the engine. So effectively you have a breather one side (positive crankcase pressure outlet) and an air inlet the other.

Yes, The breather from the flame trap goes to the air inlet with a tee piece that goes to the plenum. The Tee piece (ERR4765) is a bit special as it is built with a restrictor (very tiny hole) on the plenum side.

I wouldn’t worry too much about the rolling issue as all the top end will fill with oil if that happens……. Any oil in the breather pipes will soon disperse back into the engine (the flame trap is only a wire mesh oil separator). The correct breathing of the RV8 is important as the engine is not very tolerant of high crankcase pressures.

[FridgeFreezer]

Early ones don't have the tee.

[Bowie69]

...and later ones (4.0/4.6 serp) have rocker covers just as G describes them

Hmm, for some reason it's not allowing me to upload images to this post... oh well, here it is on the web instead:

HTH

[heath robinson]

So would it be beneficial to fit breathers to the 4.6 covers?

[Bowie69]

Well, above is how LR did it, whether it is the *best* way is a subject open to debate...

RH (on that pic) breather is the big one going into the throttle body just before the butterfly, the LH one is the thinner tube going from the rocker to the side of the plenum, just under the line coming from number 5.

That's all the breathers are on a 4.0/4.6 setup

[Mr Noisy]

Righto, thread revival!

Regards this mushroom type inlet breather on the NSR corner, I need to get sort if out, ideally linking it to my breather system.

I'm thinking cut off the disc just leaving the tube like on a carb engine cover, but I notice (assume EFi spec) that I have a teeny pinhole in mine, so I assume I need to keep that to maintain crankcase vacuum and/or to not let too much air eventually into the plenum.

Just wondering if anyone else has worked out a solution already??

Thanks!

[Hybrid_From_Hell]

I have found that the mushroom bit comes off leaving a tube sticking out I have then popped some washer clear hose on the tube and the taken this inside the 90 under the dash and then pushed the mushroom assemble back on the washer extension

I am funnily enough looking at this for megasquirt and am in the process of finishing a kit with Jose and a new push on filter that's a bit nicer than the bodgeroo above

It just needs venting via an extension nothing more complex than that :0)

[Mr Noisy]

cheers nige, will take the big grips to it and see if i can persuade the mushroom to come off.

i now have a spare breather which was previously used for my distributor so that will do nicely for this one!

[FridgeFreezer]

I think I drilled & tapped the breather hole on mine.

[zardos]

Mine was missing the mushroom, a normal breather pipe was a very good fit, so I just pushed one on and router like all the other breathers.

[Mr Noisy]

Thanks guys, yeah I'm going to pull the mushroom off and see what remains, then push a pipe over and take it to the breather system.

I wonder if the pinhole is required?