Air filter - which way up ?

[Ferd]

I am hoping this problem has one definitive answer and doesn't develop into a split decision like cassette/pumpout !

 

The air filter on our Nanni/Kubota engine fell off so I pushed it back on with the "nozzle" facing down. The first marina we came to we asked if it was fitted properly and the engineer said yes - nozzle-down.

 

Now I have googled-- nanni diesel engine air filter -- the first website to come up is A R Peachment Who in fact were the suppliers of our engine. peachment.co.uk/product/air-filter-nanni-diesel-n4-50-50hp/.

 

Their picture displays the filter nozzle-up.

 

Would be interested to hear which way the filter should be fitted, Thanks.

 

 

[RLWP]

This one?

 

 

Richard

Or maybe something like this:

 

 

I would install one of those with the inlet facing down. It's harder to lose things inside if you do. I doubt your engine cares one way or the other

 

Richard

[Tiggs]

Air filters usually have the air flowing from the outside to the inside. (certainly every motorbike, car and canal engine versions I've ever seen) The inside should have a grid which prevents filter bits getting in the engine if the filter breaks up. The outside has a bigger surface area to trap the dirt without blocking the filter.

 

Or is this not what you are talking about? just where the air goes in, face down, or at least horizontal, to stop debris getting in.

Edited May 2, 2016 by Tiggs

[Tony Brooks]

Assuming a "frying pan" air cleaner.

 

It will not matter engine wise which way you point the "handle" but there may be other considerations. If a diesel sucks water through the inlet you are likely to be faced with a very expensive bill because the pistons are likely to stop dead on a hydraulic lock and that bends connecting rods. The logic of that is to fit the handle pointing up so the intake is as far away from bilge water as possible but that introduces another potential problem. Although with the element in it it should not be possible for anything to get from the outside to the inside of the element with the "handle" pointing upwards it is easier to drop things into it. I advise that the "handle" (intake tube) be fitted a tad below horizontal so its hard to drop things into it but its a fair way above bilge water level.

 

Remember if the weed hatch is left loose or not properly sealed the bilge can fill up fairly fast.

 

[Guest]

Reminds me of the 'days of old' on cars when you used to point your filter intake over the exhaust manifold in winter so it drew in warm air and away from it in the summer.

 

Is that a consideration on a NB??

[Ferd]

This one?

 

 

Richard

Or maybe something like this:

 

 

I would install one of those with the inlet facing down. It's harder to lose things inside if you do. I doubt your engine cares one way or the other

 

Richard

 

The second one.

 

I was surprised...

1) to find it on the engine room floor

2) never to have noticed which way up it had been installed

3) even more surprised that there is no "filter" material inside. It is simply a hollow box.

4) The manufacturers/suppliers depict it intake nozzle up while the engineer suggested it fits intake nozzle down.

 

A surprising experience all round.

 

Thanks for all the replies so far.

[Tony Brooks]

Personally I doubt that is an air cleaner. I think its just an intake silencer with very little between the inlet spout and the inlet manifold so i would fit it spout pointing down.

[MoominPapa]

Reminds me of the 'days of old' on cars when you used to point your filter intake over the exhaust manifold in winter so it drew in warm air and away from it in the summer.

 

Is that a consideration on a NB??

No. That was to combat carburettor icing in petrol engines. For a diesel, the cooler the intake air the better, if you're interested in maximum power. As you're not normally bothered about power in a NB, it doesn't matter.

 

MP.

[RLWP]

 

Personally I doubt that is an air cleaner. I think its just an intake silencer with very little between the inlet spout and the inlet manifold so i would fit it spout pointing down.

 

 

Yes, I would agree with all of that

 

You could fit it with the nozzle horizontal if you are uncertain - the engine won't mind

 

Richard