Air filter housing

[Scholar Gypsy]

I am trying to find a new air filter housing for my 4 cylinder diesel engine. An old fitment is below. It fits on a 2 inch diameter pipe. (I don't have a pipe that connects to the rocker cover /crankcase). I would prefer one with a replaceable filter, rather than a washable one.

 

This seems a ridiculous question to ask here, but online has not really worked for me yet, and a good chandlery I visited recently said they were having problems sourcing them too,  Many thanks!

 

[Tonka]

Have you tried looking at one for a tractor or similar

https://agrilineproducts.com/

Might do one similar 

[Tracy D'arth]

Something like this K&N air filter.

https://www.demon-tweeks.com/uk/k-n-filters-universal-round-tapered-air-filter-244169/

[blackrose]

Is it ok to just whack any old air filter onto an engine? I would have thought the engine spec is relevant here? Different engines will require different amounts of air and if the random filter you happen to fit restricts air flow too much that wouldn't be a good thing.

[Tracy D'arth]

6 minutes ago, blackrose said:

Is it ok to just whack any old air filter onto an engine? I would have thought the engine spec is relevant here? Different engines will require different amounts of air and if the random filter you happen to fit restricts air flow too much that wouldn't be a good thing.

Not likely to matter with a slow running underworked motor in a canal boat.

[Jen-in-Wellies]

13 hours ago, Tracy D'arth said:

Something like this K&N air filter.

https://www.demon-tweeks.com/uk/k-n-filters-universal-round-tapered-air-filter-244169/

Those are washable filters, not replaceable, which the OP is looking for.

[Tony Brooks]

16 minutes ago, blackrose said:

Is it ok to just whack any old air filter onto an engine? I would have thought the engine spec is relevant here? Different engines will require different amounts of air and if the random filter you happen to fit restricts air flow too much that wouldn't be a good thing.

 

As K&N are a respected name in engine tuning circles, they are unlikely to produce an air filter that restricts the air supply. The filter linked to will fit, I think, a BMC 1.5 and although the filtering look finer than the wire mesh on the "standard" it has a far breather area so is very unlikely to restrict the air supply.

 

The range of filters fitted by marinises to engines around 1.5 litres capacity is large, from no filter as on the Vetus air boxes, through larger frying pan filters as per many Beta and Listers, to the small foam types fitted on some BMCs, and it seems to make little difference to exhaust smoke and performance, so I doubt the air restriction is a concern providing one does not do anything like fitting motor mower filter.

 

If I were the OP, I would just pipe the breather into a milk "bottle" stood in the engine drip tray. I think that would solve a lot of the filter fouling.

 

 

[blackrose]

8 minutes ago, Tony Brooks said:

 

As K&N are a respected name in engine tuning circles, they are unlikely to produce an air filter that restricts the air supply. 

 

I'm not doubting K&N's ability to manufacture an air filter, the point I'm making is that different filters will naturally allow different maximum airflows depending on their construction and overall size. Therefore I'm asking whether putting a random spec air filter onto an engine that will also have a specific airflow requirement might restrict that flow if the filter chosen happens not to have adequate airflow for the engine?

 

The specification of an air filter is not solely governed by the size of the connection to the engine surely?

Edited April 21 by blackrose

[Tony Brooks]

3 minutes ago, blackrose said:

 

I'm not doubting K&N's ability to manufacture an air filter, the point I'm making is that different filters will naturally allow different maximum airflows depending on their construction and overall size. Therefore I'm asking whether putting a random spec air filter onto an engine that will also have a specific airflow requirement might restrict that flow if the filter chosen happens not to have adequate airflow for the engine?

 

The specification of an air filter is not solely governed by the size of the connection to the engine surely?

 

The size of the inlet manifold connection will be determined by the engine manufacturer in relation to the air flow required, so there will be a relationship between connection size and required air flow.

 

Another point s that K&N main market is petrol engines, that when tuned, have peak revs of over 6000 rpm. Few, if any, boat type diesels will rev at much over 4000 rpm, so the maximum air volume required will be less on our types of diesels.

 

I suspect the OP may have a BMC 1.5 engine, so there is a good chance he could fit anything from a BMC B series engine, the MG specialists may be able to help, but the exhaust manifold cum header tank may get on the way.

[Scholar Gypsy]

2 hours ago, Tony Brooks said:

 

The size of the inlet manifold connection will be determined by the engine manufacturer in relation to the air flow required, so there will be a relationship between connection size and required air flow.

 

Another point s that K&N main market is petrol engines, that when tuned, have peak revs of over 6000 rpm. Few, if any, boat type diesels will rev at much over 4000 rpm, so the maximum air volume required will be less on our types of diesels.

 

I suspect the OP may have a BMC 1.5 engine, so there is a good chance he could fit anything from a BMC B series engine, the MG specialists may be able to help, but the exhaust manifold cum header tank may get on the way.

Thank you, it's a Mitsubishi K4, so a bit bigger.  To be honest the main reason I want an air filter is to stop screws dropping into the inlet manifold, which I believe doesn't improve performance.   

I do have a K&N at the moment, my main issue is that it can come off a bit too easily, as the rubber flange is not very high.

[Martin Nicholas]

41 minutes ago, Scholar Gypsy said:

To be honest the main reason I want an air filter is to stop screws dropping into the inlet manifold, which I believe doesn't improve performance.

If that's all you are after, then buy a silicone hose elbow and point it downwards. Trim it if needed.

[StephenA]

We have one just like that on Mintball. The iron wool style filling fell apart. We now use strips of green scouring pads fitted round the inside of the casing and just throw them away at regular intervals.  If you don't have a crank breather pipe then just block the hole off

Edited April 21 by StephenA

[Peugeot 106]

The Lister Alpha range used specify a restrictor in the air inlet manifold for engines running at or below 1800 rpm. I believe that this was to achieve  crankcase vacuum at low speeds but I stand to be corrected. Fitting too small a filter or running with a dirty filter would also increase crankcase vacuum. You can easily demonstrate this by putting a manometer down the dipstick and blanking off the air inlet with your hand.

3 hours ago, blackrose said:

 

I'm not doubting K&N's ability to manufacture an air filter, the point I'm making is that different filters will naturally allow different maximum airflows depending on their construction and overall size. Therefore I'm asking whether putting a random spec air filter onto an engine that will also have a specific airflow requirement might restrict that flow if the filter chosen happens not to have adequate airflow for the engine?

 

The specification of an air filter is not solely governed by the size of the connection to the engine surely?

 

[David Mack]

2 hours ago, Scholar Gypsy said:

I do have a K&N at the moment, my main issue is that it can come off a bit too easily, as the rubber flange is not very high.

Could you fit some sort of adapter between the manifold and the filter housing?