What should be in my air filter

[Mike Barber]

Hi new member here are newish to boating 

 

Took my air filter off to see if it needed cleaning / replacing - Its from a Nanni 4110KC Diesel engine and its an empty plastic box 

 

Question is should it be empty or should there (as i imagine) be a filter material inside it please ? Checking before i go out and spend the money on a new one as the seem to be about £78 which seems a fair bit 

 

Have attached a photo 

 

Thanks in advance for any help

 

[Tony Brooks]

I doubt anything is inside it, it is just an intake silencer, similar to what is on some Vetus engines. There is not so much dust and grit in the air when at sea, so why fit anything more. Give the spout a good blow, I bet there is no resistance at all.

Edited April 23, 2023 by Tony Brooks

[David Mack]

Spend £78 and you'll have another empty plastic box. Narrow boat engines don't really need air filters, unlike their cousins used in plant and equipment which may be operating on dusty construction sites.

[mrsmelly]

As others have said, no filter needed. I have owned a couple of boats without filters, one was a vetus. That was the only cheap thing about the vetus 🤣

[Mike Barber]

Thanks everyone appreciate the help, and saved me £78 for another plastic box 😁👍would have been a classic 

[peterboat]

I disagree, boats need air filters just buy a cheap washable one of Ebay something like this

 

1 hour ago, mrsmelly said:

As others have said, no filter needed. I have owned a couple of boats without filters, one was a vetus. That was the only cheap thing about the vetus 🤣

Tim my air filter on my last boat engine was clogged solid when I bought the boat! First thing I did was change it, strange though it had been serviced by a marina before I bought it

[Tony Brooks]

A little story from the time I was an apprentice that I was told by a London Transport mechanic. In those days they used to overhaul the engines of the buses at many, many thousands of hours if they needed it or not and completely rebuilt the buses and even more thousands of hours. The chap said that the top engineers found that by not fitting air cleaner elements during routine servicing, they saved more than the cost of the excess engine wear.

 

I am with David on this one, in boat use you will not be able to discern the effect of not using an air filter element.  There must be thousands of BMC 1.5s running in boats where the wire mesh sir cleaners have never been oiled so can't catch any dust. The only exception just might be if you have a hairy pet that sheds hairs, but I expect any airs that find their way into the engine will just burn to ash and get blown out of the exhaust.

[Mike Barber]

I recon it defiantly needs the box, if not an actual filter, if I went for a different filter I’d need a solution for the pipe that runs off the top of the block into the filter box - presume this is some sort of air pressure release / recirculation pipe ? 

[Tony Brooks]

28 minutes ago, Mike Barber said:

I recon it defiantly needs the box, if not an actual filter, if I went for a different filter I’d need a solution for the pipe that runs off the top of the block into the filter box - presume this is some sort of air pressure release / recirculation pipe ? 

It is the crankcase breather. it goes into the inlet because it is now bad form to emit oily exhaust fumes into the atmosphere, but the engine would be fine f the hose was left dangling, although it may spit some oil drops. You could drill the inlet manifold to accept that pipe.

[blackrose]

7 hours ago, peterboat said:

I disagree, boats need air filters just buy a cheap washable one of Ebay something like this

 

I disagree too. If air filters aren't needed on boats them why was my engine supplied with one and why is the element always dirty when I change it?

[peterboat]

51 minutes ago, blackrose said:

 

I disagree too. If air filters aren't needed on boats them why was my engine supplied with one and why is the element always dirty when I change it?

I am an engineer to trade started at 12 with old motorbikes later repairing mowers down the road, then at 17 generators in the Army. They all had air filters, as time went on boats came along still had air filters. An open air intake is a recipe for disaster when a screw or nut gets dropped in a running engine! But what do we know?

[Mike Barber]

4 hours ago, Tony Brooks said:

It is the crankcase breather. it goes into the inlet because it is now bad form to emit oily exhaust fumes into the atmosphere, but the engine would be fine f the hose was left dangling, although it may spit some oil drops. You could drill the inlet manifold to accept that pipe.

Great stuff thanks Tony