Rocker box breather.
Discussion
Thats the restricted air inlet - the outlet is on the offside flame trap.
If you don't know what you are doing you will end up with no vacuum in the crank case resulting in oil leaks, crap oil......
That inlet BTW seems to be a common problem, good ones you can suck through but can't blow so they are definitely also a valve IMO - cleaning out with drills etc / replacing with mini filters are all recipes for disaster in my book.
The mushroom filter clips onto a flat cap with a stem which is pressed into the rocker cover, you can carefully prize them out using 2 pry bars at opposite sides under neath - just work around lifting them gently & straight.
If you don't know what you are doing you will end up with no vacuum in the crank case resulting in oil leaks, crap oil......
That inlet BTW seems to be a common problem, good ones you can suck through but can't blow so they are definitely also a valve IMO - cleaning out with drills etc / replacing with mini filters are all recipes for disaster in my book.
The mushroom filter clips onto a flat cap with a stem which is pressed into the rocker cover, you can carefully prize them out using 2 pry bars at opposite sides under neath - just work around lifting them gently & straight.
haircutmike said:
Here's my problem Spend.
Road work, all is fine, flat out on the track and I am getting oil leakage through the mushroom!
The mushroom in on the nearside rear box.
The breather from the flame trap goes to a catch tank.
1. does it also go into the inlet to create a vacuum - I suspect not!Road work, all is fine, flat out on the track and I am getting oil leakage through the mushroom!
The mushroom in on the nearside rear box.
The breather from the flame trap goes to a catch tank.
2. has the 'mushroom' been 'cleaned' out so it is now not a one way valve - I suspect it has.
Positive crankcase ventilation is a good thing, you might dislike the crap it leaves in the trumpet base (but that is largely due to lack of maintenance - Rover specced cleaning out flame trap & pipework at every service which I've never seen to be observed). Without it you're just pumping oil/air all over the place and since its at pressure it will try & go everywhere rather than under vacuum when it is more likely to return to the sump. Bear in mind dry sump systems also pull vacuum in the crankcase in race engines
and thats not for oil economy 
There seem to more balls ups with catch tanks than upgrades IMHO, just sticking them on because you think it is a good idea and might cure some other obscure fault is just flawed thinking?
4.6's and some other LR's instead of the mushroom filter & valve stem have a tube fixed into the rocker that is piped to the air filter cannister. That balances pressure, low pressure as engine is also sucking air at the filter and even lower pressure behind the butterfly where the flame trap is connected (particularly when the throttle is closed). Note that neither orofice is connected to atmosphere...
Getting the balance of how much / when (negative) pressure is created and how much flows through is best left to the manufacturer set up IMHO as its quite a complicated calibration of valves / pipes around varying pressure points ~ and also related to an engines mechanical characteristics as well I guess.
If you must plumb in a catch tank just ensure it maintains the pressure & flow by inserting it into the pipework off the flame trap, with the manifold still able to pull air/gas through it.
I still suspect the main reason to insert one is more likely bad maintance or damage to the simple constituents of the original components (mushroom stem & filter, flame trap insert, bias valve twixt fore/aft of throttle and pipes). It isn't a complicated set of parts and simple cleaning with solvents & brushes (not gouging out!) is all that is really required IMO.
Getting the balance of how much / when (negative) pressure is created and how much flows through is best left to the manufacturer set up IMHO as its quite a complicated calibration of valves / pipes around varying pressure points ~ and also related to an engines mechanical characteristics as well I guess.
If you must plumb in a catch tank just ensure it maintains the pressure & flow by inserting it into the pipework off the flame trap, with the manifold still able to pull air/gas through it.
I still suspect the main reason to insert one is more likely bad maintance or damage to the simple constituents of the original components (mushroom stem & filter, flame trap insert, bias valve twixt fore/aft of throttle and pipes). It isn't a complicated set of parts and simple cleaning with solvents & brushes (not gouging out!) is all that is really required IMO.
Of interest on the mushroom breather. This has been the subject of some "interest" from MSA Scrutineers (at Prescott).
Many of our Speed Champs members have "manufactured" various pipes & containers purporting to be catch tanks to meet the Blue Book rule, which satisfied the Prescott Scrutineer. All have been dry, without a drop of oil - OK, we run near max beans from 35 secs to 70 secs or up to 90 secs at a Sprint
At all other venues (Shelshley/Loton/Gurston) the "MSA" view was it was an inlet breather not liable too "dump" oil even when upside down!!
On my 400 the breather is only 60 thou in diameter - I removed it and replaced with a solid rivet, siliconed in - I have had no change in running or oil leaks?? Plus no problem with Prescott MSA Scrutineer.
If yours was sealed, rather than opened to a tank, would it have any effect other than you won't have a wet sponge filter ??
Agree the flame trap needs some vacuum to draw the fumes!!
HTH
Trev
Many of our Speed Champs members have "manufactured" various pipes & containers purporting to be catch tanks to meet the Blue Book rule, which satisfied the Prescott Scrutineer. All have been dry, without a drop of oil - OK, we run near max beans from 35 secs to 70 secs or up to 90 secs at a Sprint
At all other venues (Shelshley/Loton/Gurston) the "MSA" view was it was an inlet breather not liable too "dump" oil even when upside down!!
On my 400 the breather is only 60 thou in diameter - I removed it and replaced with a solid rivet, siliconed in - I have had no change in running or oil leaks?? Plus no problem with Prescott MSA Scrutineer.
If yours was sealed, rather than opened to a tank, would it have any effect other than you won't have a wet sponge filter ??
Agree the flame trap needs some vacuum to draw the fumes!!
HTH
Trev
I guess with my current set up, I have no vacumn therefore fumes aren't being sucked out of the flame trap, (or not enough) and that pressure is being exhausted out the "mushroom"!
When tracking at full chat for 20-30 minutes at a time, this causes problems especially as a larger quantity of oil is pumped up to the top of the engine!
When tracking at full chat for 20-30 minutes at a time, this causes problems especially as a larger quantity of oil is pumped up to the top of the engine!
When I initially changed from the later Rover rocker covers to the nice cast TVR ones, there was no mushroom but all the othre PCV stuff. It smoked horribly until I let a mushroom into the cast cover. Conclusion is the air bleed is necessary to equalise the vacuum without inducing excessive blow-by.
Now I'm routinely running much higher rpm than most RV8s see day to day, I'm convinced a bigger capacity bleed in would be beneficial as I stil get an oil haze at the top end on big loads.
There's no valve in the mushroom. Hold a new one up to the light and you can see clean through it
Now I'm routinely running much higher rpm than most RV8s see day to day, I'm convinced a bigger capacity bleed in would be beneficial as I stil get an oil haze at the top end on big loads.
There's no valve in the mushroom. Hold a new one up to the light and you can see clean through it
My 400 SE is now fitted with a flame trap and a pipe leading to the front under part of car and there are no oil leaks and no oil loss and the performance is perfect. The plenum inlet where the flame trap pipe was once connected to is sealed off. I can hardly smell the fumes delivered out the pipe from the flame trap as the pipe is placed at the tip front end of the car facing downwards. Advantages? well the oil fumes are not fed into the plenum so cleaner exhaust and less exhaust emission.
Tony. TCB.
Tony. TCB.
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