Swirl Control removed from NW engines

[famcc]

I've just noticed NW engines have no swirl control. The inlet manifold is a different configuration, no solenoid and a plug has been place on the vacuum pump. Maybe MM have finally conceded that they are more of a nuisance. Should we consider disabling it on all previous models?

[MatthewP]

Swirl valves like they are on the Pajero are of negligible benefit on a diesel, even before they get covered in egr crap.

It is a common mod on some other vehicles to disable or remove them, not for any real performance benefit, just because its one less thing to go wrong.

Because MM have removed them from later models shows that they aren't needed for anything worthwhile.

Matt

[Goodsy]

Mine have been unplugged for well ages. I see them as a restriction in the intake system.

[DaveE66]

Mine have been unplugged for well ages. I see them as a restriction in the intake system.

Hi Goodsy
Can I ask how you disconnect it.

Regards
Dave

[pasniny]

Pull the vacuum hose off actuator and blank it manifold end

[Stoneman]

Ball bearing in vacum hose

[DaveE66]

Thanks much apperciated

[awill4wd]

Ball bearing in vacum hose

Yep, the same solution for me.
From memory I think it was the hose with the yellow stripe, but not 100% sure.

[MatthewP]

I was just looking through a thread on manifold cleaning and looking at the photos of the intake manifold with the swirl control valves.
.http://www2.pajeroclub.com.au/forum/...t=29947&page=7
.
The the way that the entrance to some of those runners are shaped because of the swirl valves is terrible.

If you are going to disable the swirl control and have the manifold off for cleaning at some stage, I think it would be worth seeing how much it would cost to get a workshop to mill out all the extra material around the swirl valves and open it up a bit.

Even just pulling out the swirl valves yourself and trying to clean it up a bit with a dremel would have to make a difference.

Also getting a spacer made up to fit between the main part of the lower intake manifold and its cover to increase the volume of the plenum would probably have some benefit too.

Matt

[JoeMcDermott]

Swirl valves? This is the first time I have come across the name.

Are they a sort of Mitsubishi Hiclone?

[Goodsy]

Google will help you here.
The basically partially close at lower RPM to increase the
speed of the intake air across the intake valves.
Very simple explanation.

[Stoneman]

Are they a sort of Mitsubishi Hiclone?

Haha, yep!

[MatthewP]

Google will help you here.
The basically partially close at lower RPM to increase the
speed of the intake air across the intake valves.
Very simple explanation.

It makes a difference on NA petrol motors because with intake ports that are designed to breath well at full throttle, when there is low throttle there is less air to enter the intake so it moves slower so the swirl valves are used to speed it back up for more efficient filling of the combustion chamber.

All of this is completely useless on a Turbo Diesel, so it must be there because of the egr crap.

[P4J3R0]

1 more thing to add to the list of things to do on the paj at the next service. I have some 10mm plate lying around that will make a great spacer once cut to the right shape with the plasma. Might make a template so I can get some laser cut if other are interested.

[MatthewP]

1 more thing to add to the list of things to do on the paj at the next service. I have some 10mm plate lying around that will make a great spacer once cut to the right shape with the plasma. Might make a template so I can get some laser cut if other are interested.

If you're able to, it would be worth getting the template made up, not just to help out other people, you may want to play around and try out thicker spacers at some stage.

Matt.

Edit.

Does anyone have any photos or links to threads with photos of the NW inlet manifold, that has been opened up for cleaning?

It would be interesting to compare the intake with the swirl valve against one without it.