Rocker Cover Vent

[LRDV8]

Hi all,

On my V8 S2 Disco it has the breather tube from the rocker cover vent plumbed into the bottom of the airbox. I'm sure this is good in thoery but i'm finding that as a result my air filters are clogging up rather quickly from the oil vapour mixing with the dust being sucked into the airbox and killing my filters ?:(

Anyone experience this ? Is it just one of those problems that i live with ?

Have thought about putting in an oil catch can or just putting a rocker breather/filter directly ontop of the rocker cover ?

[p38arover]

That seems an odd place to vent it. Normally it goes downstream of the aircleaner and the MAF sensor (you don't want oil on the sensor) - but I haven't looked at the Thor engine.

Has your car been converted to LPG where the fitter has moved the hose?

Ron

[LRDV8]

Yea i thought it was a strange place for it to be installed but i had convinced myself that i had just not noticed it in the past ? Funny you should mention the LPG installation as i have noticed it to be worse on airfilters since the LPG installation - so yes i would say that they have taken it upon themselfs to move it there.

Cheers Ron;)

[p38arover]

I was at Davis Performance Landys last week and Bruce Davis looked at mine and said that the crankcase vent didn't need to be moved on RR V8s. (Mine is downstream of the MAF sensor)

The reason for moving them was to prevent LPG filling the crankcase under some situations with the subsequent risk of an explosion.

It's been common practise for LPG fitters to move that hose - it could be a carry over from the days of carburettors.

Ron

[Blknight.aus]

cut the hose and add one of those $3 filters from an cheapo auto shop so that the natural air flow goes Up through the filter it'll slow down the leak immesurabley.

If possable place the filter so the whole filter and hose from the rocker naturally runs downwards to the rocker with no traps in it and in all likely hood you'll never have to change the filter either.

[PhilipA]

Is the Disco a Thor?
If so it pulls air from the front of the manifold after the throttle body. There should be a 1 way valve in the hose.
The vent is also on the LH rocker and vents before the Throttle plate, on the rear of the throttle body.
So the LPG installer must have moved them.
I do not know where you could put it without a problem if it has to be before the LPG mixer. I assume you have an older type LPG conversion.
maybe put a catch can a seperator in the circuit, and then change the position on teh air cleaner housing to after the air cleaner. You will still ahve a problem wit h the MAF. If you have room , put it between the MAF and LPG mixer.

Regards Philip A

[Ken]

Would blanking where the hose vents into the manifold and just before the throttle body cause any problems as I have just been out to have a look at mine and am considering two small filters one for each side (Sorry for hijacking thread ) I have a problem periodically which seems like flooding only when turning a corner .
Would this be caused from oil on the MAP sensor ?

[Blknight.aus]

Would blanking where the hose vents into the manifold and just before the throttle body cause any problems as I have just been out to have a look at mine and am considering two small filters one for each side (Sorry for hijacking thread ) I have a problem periodically which seems like flooding only when turning a corner .
Would this be caused from oil on the MAP sensor ?

Im not sure if I understand your plan exactly but a generic warning.

The crank case vent is there to get the small amount of blowby you get during combustion out of the sump. If you leave it there eventually your oil turns acidic. Which admitedly makes for very nice shiney engine internals but sadly is not conducive to long engine life.

short version.. Dont totally block the breather dats bad.

[Ken]

Im not sure if I understand your plan exactly but a generic warning.

The crank case vent is there to get the small amount of blowby you get during combustion out of the sump. If you leave it there eventually your oil turns acidic. Which admitedly makes for very nice shiney engine internals but sadly is not conducive to long engine life.

short version.. Dont totally block the breather dats bad.

I want to put a filter on each vent hose that protrudes from the rocker covers themselves
These tubes vent into just before the throttle body (Passenger side )
And Into the manifold (Drivers side) if I blank off the points of entry I shouldnt have any problems ?

[PhilipA]

I do not see how the crankcase vents could have any possible effect on a miss while going around corners.
When you ( I presume) last asked, I suggested a diagnostic. I still do.

regards Philip A

[Blknight.aus]

I have an idea on how it could feasabley happen but the odds of it actually happening are like me winning lottery (it involved multiple sequential failures that would have a lot of other symptoms besides missing on corners). There are a lot of intermittant faults that have the potential to provide missing on cornering from a loose fuel pump connector right up to a loose sparkplug (and every other component between those 2 items) It could just as easily be a bad earth cable that looses conductivity when turning due to the flex it places on the cable.

If you block the outlet of the hoses before they plumb into the inlet manifold youve essentially blocked the hose and the aforementioned problem of shiney but useless engine parts ensues.

Doing the filter thing I mentioned previously might prevent more oil getting into the inlet manifold. But if thats the root cause then the damage is done already and your up for new sensors.

But the short version.. Follow phillipA's advice get it checked properly

[Ken]

Thanks guys will do

[LRDV8]

Thanks for the feedback guys. Just one last thing......... how do i know if i have a thor engine ?? :eek: what is the other type ??

[p38arover]

If you have a Series II Disco, you have a Thor - it looks like this:


https://www.aulro.com/afvb/images/imported/2007/09/95.jpg

It will have the bunch of snakes inlet manifold that is totally different in appearance to all previous EFI Rover V8s.

[LRDV8]

yep thats mine !!

[p38arover]

OK, you should not use a venturi LPG system with that engine. They are well known for backfiring and destroying airboxes.

One should only use a sequential vapour injection system with the Thor (Bosch Motronics) engine.

I'm having an SVI system fitted to mine.

Ron