Engine air filters, for very-dusty conditions?

[Bugger]

I got a few of the Type 2 std airfilters that uses oil and their connecting hoses

That tall housing filters is what I have they work very well

[Nigel A. Skeet]

Air filter (in the 65 Kombi we had when i was a child) was similar to the one in above photo. Was just a massive oil bath unit, plenty wires inside, don't think it was cyclone. (Opened it to see what's inside while still in primary school).Think it was made by MANN. Don't know if that size was standard or optional and which years had them. Fig will know.

I got a few of the Type 2 std air filters that uses oil and their connecting hoses

That tall housing filters is what I have they work very well

One publication (i.e. Vincent Molenaar & Alexander Prinz, "VW Transporter & Microbus - Specification Guide 1967~79", The Crowood Press, 2005, ISBN 1-86126-765-7, Chapter 7: Optional Equipment, Pages 51 & 56), cites the following M-Codes, for 1968~79 VW Type 2s.

M-Code 153 | Paper element cyclone air filter without carburettor pre-heating (1300 & 1600 cc engines only) | All models | 1975~79

Note that instead of the 1600 cc engine, the 1300cc engine was available as a factory-fitted option for the Italian specification, 1971~75 VW Type 2, under M-Code 252.

M-Code 155 | Two oil bath air filters with larger oil capacity | All models | 1968~74

M-Code 156 | Oil bath air filter with larger oil capacity for dusty regions | All models | 1968~74

M-Code 569 | Air filter for dusty conditions (2000 cc with 70 bhp only) | All models | South Africa & Australia

It's possible that these tall oil-bath air cleaners, might correspond to M-Code 155 or 156.

As previously stated, despite the large dust retention capacity of oil-bath air cleaners, their filtration efficiency is not particularly good; being less than 91%, according to the following literature:

T. K. Garrett, K. Newton & W. Steeds, "The Motor Vehicle", Butterworth-Heinemann (on behalf of American Society of Automotive Engineers Inc.), 13th Edition, 2001, ISBN 0-76800-639-2, Pages 554~555.

« For heavy commercial vehiclres, especially if operating in dust-laden atmospheres, for example on civil engineering sites, a centrifugal filter may be incorporated on the inlet side of either an oil bath filter or paper or felt element. Centrifugal filters are constructed so that air entering is guided by vanes or a volute to follow a spiral path in a housing, so that heavy particles in the air are centrifuged out to the walls. On striking the walls, the particles lose momentum and drop into the base. »

« Used alone, they would not remove the finer particles. Over unmade roads and tracks, the dust content of the atmosphere can be as high as about 45 g/m³, so over a distance of 600 miles an unfiltered engine might induct as much as 50 g of dust. »

« Although the oil bath type can trap a larger volume of heavy particles before it needs to be cleaned, the paper element type has a higher filtration efficiency, generally between 91% and 99•7% when tested to BS 1701. »

[eben]

...but..... a paper air filter would be clogged and choking your engine loooooong before an oil bath filter would in dusty conditions.
In fact: the "filtering efficiency" of the paper element would get so high it would hardly let any air in

[fig]

The large oil-bath air filters fitted as standard on all SA buses from 64-69 or so were the same as M156 (SA buses did not have M-codes).

I don't know anything about relative efficiency of different filters, but I swear by oil bath filters for African conditions.

When crossing the Nubian desert in Sudan in the ZebraBus, the oil bath became an almost solid cake of oily mud, with just the thinnest layer of oil on top. Despite that, I couldn't see or feel any grit in the pipe between filter and carb, or in the carb. After that incident, I made a point of cleaning the filter more often.

[Nigel A. Skeet]

The large oil-bath air filters fitted as standard on all SA buses from 64-69 or so were the same as M156 (SA buses did not have M-codes).

I don't know anything about relative efficiency of different filters, but I swear by oil bath filters for African conditions.

Comparative filtration efficacy and airflow tests for different types of automotive air filter elements

http://www.bobistheoilguy.com/airfilter/airtest1.htm

http://www.bobistheoilguy.com/airfilter/airtest2.htm

http://www.bobistheoilguy.com/airfilter/airtest3.htm

When crossing the Nubian desert in Sudan in the ZebraBus, the oil bath became an almost solid cake of oily mud, with just the thinnest layer of oil on top. Despite that, I couldn't see or feel any grit in the pipe between filter and carb, or in the carb. After that incident, I made a point of cleaning the filter more often.

If my own German built, British specification, 1973 VW 1600 Type 2 Kombi based, Westfalia Continental campervan, is any indication, it would seem that British specification VW Type 2s, didn't have M-Code plates either!?!

Your experience regarding the "solid cake of oily mud", does not surprise me, given what the text books state about the atmospheric-air's dust content, under desert conditions. Surprisingly, nowhere within the official two-part, 1973 VW owners' handbook (as indicated below), is there any mention of service intervals for the oil-bath air filter, under any prevailing conditions!

Instruction Manual Part 1 | Operation and Data | VW Transporter | Volkswagenwerk AG, Wolfsburg, August 1972 | 2.83.562.006.20

Instruction Manual Part 2 | Driving, Car Care, Do-it-yourself | Type 1, 2, 3 and 4 | Volkswagenwerk AG, Wolfsburg, August 1972 | 2.83.5.69.001.20

However, the Haynes Owners Workshop Manuals, advise one, that under very dusty conditions, the oil-bath air cleaner, should be inspected and cleaned as necessary, at least weekly or possibly even daily intervals.

J. H. Haynes & D. H. Stead, VW Transporter 1600, 1968 to 1972, Owners Workshop Manual, J. H. Haynes & Company Ltd., 1974, ISBN 0 900550-82-1; Chapter 3 - Fuel System & Carburation; Section 2 - Air Cleaner, Page 58.

« The oil, when at the correct level should be at least 5 mm deep above any accummulations of sludge. Under average conditions the filter should not need attention at less than 6000 mile intervals. In dusty conditions the frequency will increase and only experience will give an indication. If the extreme - such as driving across desert with no hard top road surfaces - is encountered it will be necessary to check daily. If the cleaner is neglected the air intake passages through the cleaner will become restricted resulting in a rich fuel mixture and poor performance. »

J. H. Haynes & K. F. Kinchin, VW Transporter 1700/1800, 1972 to 1974, Owners Workshop Manual, J. H. Haynes & Company Ltd., 1975, ISBN 85696-229-0; Chapter 2 - Carburation, Fuel & Emission Control Systems; Section 3 - Air Cleaners, Page 45.

« The frequency of servicing depends largely on local conditions. In very dusty places weekly or even daily. In normal conditions monthly or even longer periods may suffice. There should be a minimum of 3/16 inch (5 mm) of oil on top of the sludge for efficient working. Experience will soon dictate the time interval required but it is better to clean too often than not soon enough. »

J. H. Haynes & K. F. Kinchin, "VW 411 & 412, Owners' Workshop Manual; 1679cc & 1795cc; 1968 to 1975", Haynes Publishing Group, 1988, ISBN 1-85010-452-2; Chapter 2 - Fuel System: Twin Carburettors, Section 2 - Air Cleaners (With Preheating), Page 48.

« The frequency of servicing depends largely on local conditions. In very dusty places weekly or even daily. In normal conditions monthly or even longer periods may suffice. There must be a minimum of 3/16 inch (5 mm) of oil on top of the sludge for efficient working. Experience will soon dictate the time interval but it is better to clean too often than not soon enough. »

The celebrated Arthur Barraclough, religiously cleaned out the oil-bath air cleaner, on a daily basis, when crossing deserts, in his much modified, 1970 VW "1600" Type 2. He later relocated the air-filter inlet, to within the vehicle's passenger cabin, to minimise the mass of inducted dust!

Bay Window Bus > Arthur Barraclough's, much vaunted, modified, 1970 VW Type 2

http://www.thesamba.com/vw/forum/viewtopic.php?t=196043

Heinz Heisler, "Vehicle & Engine Technology", Arnold, 2nd Edition, 1999, ISBN 0-34069-186-7: Chapter 23 - Diesel-Engine Fuel Injection Systems, Sub-Section 23.11.4 - Heavy-Duty Oil-Bath Air-Cleaner, Page 609.

« The inner and outer containers should be cleaned and filled with oil and the lower detachable wire mesh should be removed and replaced at regular intervals of about 8000 km, depending on operating conditions. Under severe operating conditions, as in some African territories or under unusually severe conditions in the United Kingdom - such as road construction, demolition, sand and gravel pits etc. - service attention to the cleaning may be necessary at least every 1200 km and in extreme cases every day. »

...but..... a paper air filter would be clogged and choking your engine loooooong before an oil bath filter would in dusty conditions.

In fact: the "filtering efficiency" of the paper element would get so high it would hardly let any air in

That is why, when regularly operating a vehicle under dusty conditions, it is recommended that one use a two-stage air cleaner, so that the majority of dust is first removed utilising inertial effects, before the air flow reaches the normal paper-element filter or oil-bath air cleaner, as discussed in my article and the following references!

Heinz Heisler, "Vehicle & Engine Technology", Arnold, 2nd Edition, 1999, ISBN 0-34069-186-7; Pages 561~562 & 606~609.

T. K. Garrett, K. Newton & W. Steeds, "The Motor Vehicle", Butterworth-Heinemann (on behalf of American Society of Automotive Engineers Inc.), 13th Edition, ISBN 0-76800-639-2 2001, Pages 508~513, 526~527 & 554~555.

On pages 606~609, the former of these two references, describes and illustrates with cross-sectional schematic diagrams:

Sub-Section 23.11.1: Medium-duty dry air-cleaner

Sub-Section 23.11.2: Heavy-duty duo-dry air-cleaner

Sub-Section 23.11.3: Medium-duty oil-bath air-cleaner

Sub-Section 23.11.4: Heavy-duty oil-bath air-cleaner

By a strange coincidence, there is an on-going discussion about such a two-stage air cleaner versus the conventional single-stage air filter, on the Australian Kombi Club forum; including a comment to the effect, that VW of Australia, introduced a Donaldson cyclonic filter system, for 1972~79 VW 17/18/2000 Type 2s, which were operated under dusty conditions, owing to engine rebuild claims under warranty.

Kombi Club Forums > Help and Assistance > Bay Tech Clinic > Engine & Transmission > Stock air cleaner

http://forums.kombiclub.com/showthread.php?t=23366

« Donaldson is not aftermarket but a genuine upgrade for Kombis that travel on dirt roads after they found that the stock filter was not up to it. After numerous warranty engine rebuilds the engineers at VWA turned to Donaldson for Australian conditions. »









http://www.donaldson.com/en/engine/supp ... index.html

[Nigel A. Skeet]

More recently, two Dutch brothers from The Netherlands, drove a North American specification, 1979 VW 2000 Type 2 ASI Riviera campervan, from Amsterdam, in The Netherlands, to Beijing, in China, for the 2008 Olympic Games; encountering very dusty conditions en route.

I have just learned from Ralph van den Houten, that he and his brother Lucas, are embarking on a 20,000 km trek next year, in their 1978 VW 2000 Type 2 ASI Riviera campervan, from Amsterdam in The Netherlands, to Capetown in South Africa, so there is even greater impetus, to thoroughly investigate air-filtration & oil-filtration options.

http://www.oranjetrophy.nl/

From the above link, it seems that they might be following a similar route in reverse, to that taken by Christian Figenshou a few years ago, in his 1975 VW 1600 Type 2 Fleetline Kombi, "The Zebrabus", which sustained severe engine damage in Egypt, owing to being refuelled with 80 octane petrol.

http://www.zebrasafari.co.za

http://www.zebrasafari.co.za/journal/j_ ... #breakdown

http://www.zebrasafari.co.za/route.html

I tried the following link from Christian's website, but it no longer seems to function!

VW Service Bulletin Z4: Instructions for Tropical Climate Operation VW factory modifications for travel in extreme climates and poor roads.

http://www.mg.co.za/oldvolks/z4contents.html

[eben]

Fig, fix your website

[mikefenton]

Some pics of the broken original filter






As for the measurements im thinking of taking out the filter completly since its stopping the one panel from comming out.
so when its out i can take measurements for u Nigel

[Nigel A. Skeet]

I don't know anything about relative efficiency of different filters, but I swear by oil bath filters for African conditions.

When crossing the Nubian desert in Sudan in the ZebraBus, the oil bath became an almost solid cake of oily mud, with just the thinnest layer of oil on top. Despite that, I couldn't see or feel any grit in the pipe between filter and carb, or in the carb. After that incident, I made a point of cleaning the filter more often.

The following chart, which formed a part of the Canadian Fish carburettor brochure, compares the degrees of engine wear, associated with a micronic air filter and an oil-bath air cleaner.



Donaldson TopSpin™ air pre-cleaner

http://www.donaldson.com/en/engine/supp ... 000207.pdf

http://www.odms.net.au/files/organise/d ... 111107.pdf


In the following topic thread, of the Australian Kombi Club forum, Steve (aka Kombi Rescue), remarked that the high air intakes, on the post-1961, Australian specification VW Kombis, arose because of the Australian VW engineers in Melbourne, smearing grease on the outside of the rear, side panels and then noting where the dust mostly adhered.

Bay Tech Clinic > Body > Air Scoops

http://forums.kombiclub.com/showthread.php?t=19823

It is doubtless better, to induct the least dusty ambient air available, into the engine compartment, so that less dust needs to be filtered out. The celebrated Arthur Barraclough, modified his British specification, 1970 VW "1600" Type 2, by sourcing the engine's combustion air, from inside the main passenger cabin.

In a book, I recently borrowed from my local public library, I came across the following information about air intakes and combustion-air, air filters, for the Australian & South African specification, VW Type 2 Kombis, plus Single-Cab & Double-Cab Pickups.

It seems that in Australia, a Donaldson air filter was introduced, for pre-1968 VW Type 2s, as a VW dealership supplied, retro-fit kit, sometime prior to mid-1962 and became standard equipment from mid-1962 onward, so presumably something similar was specified for the 1968~79 VW 1600 Type 2s!?!

David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [Chapter 4 - Specification Detail Changes Month by Month, Pages 23~36].

Illustrated on Page 35

Australian 1962~66 VW Type 2 - nine, long, outward facing, horizontal, engine-compartment, air-intake, cooling slots, above the swage line (i.e. at same level as side windows)

Australian 1966~67 VW Type 2 - two sets of nine, short, outward facing, horizontal, engine-compartment, air-intake, cooling slots, above the swage line (i.e. at same level as side windows)


David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [ Chapter 6 - Optional Equipment (M Codes), Pages 41~45].

Extract from Pages 41 & 43

M004 | Dust-free air intake (Pick-Up)

M010 | Dust filters for engine compartment

M155 | Cyclone air filter (export)

M156 | Larger oil bath air filter

Illustrated on Page 44

Cab front peak, with dust-free air intake (M004) for engine compartment of Pick-Up


David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [ Chapter 9 - Transporters Assembled or Built Overseas - Australian Transporters, Pages 54~58].

Extract from Page 55:

« The actual production vehicles built and assembled at Clayton had some minor differences to the Hannover vehicles which are unique to VWA-built Transporters. The most obvious external difference is the positioning of the row of air vents above the swage line - a climatic necessity in the hot, dusty Australian environment. This was introduced in 1961/62 and used the new body-shop facilities. In 1966, this became a double row of air vents above the swage line. The CKD kits had the vents below the swage line, as normal. »

Extract from Pages 56~57

« Australian buses had to cope with extreme heat and dust conditions. Many Australian roads were (and still are) unsealed dust roads, and for the VW Transporter, designed with an air-cooled engine located at the rear with cooling air being drawn in from the air vents, dust became a major problem, leading to overheating and engine failure! To get around this problem many owners had the dealership or local garage fit a Snorkel device from the inner upper rear body panels with the air-intake grille and coupled these with large capacity hoses to the engine filter. Many buses were also fitted with the larger oil bath cleaner (M516) or the cyclone air-filter (M155) options. »

« There is also a large-capacity paper cartridge filter, the 'Donaldson Type', which was available as an official kit to be fitted by VW dealers. On 3rd July 1962, the paper air-filter arrangement on all Transporters became standard, with the paper air filter housed in a metal case and fitted to the elbow. This meant that the air pre-heating flap valve and hose were dropped, and the outlet in the heater box and the grommet hole in the engine front cover plate weesealed with metal plugs. The fuel filler flap was also fitted with an extra rubber seal to increase dust entry protection. »

« Quick to recognize the dust problem, VWA also utilized a special conversion to the body on the most abused of the commercials - the Pick-Up. The solution - duct clean air from the front instead of via the vents at the back! This was in fact an existing Hannover Special Equipment option (M004), but became standard Australian Pick-Up specification from 1962. »

« This special version of the Single Cab Pick-Up had a double roof with a second roof panel, allowing clean air to enter above the windscreen. This was separate from the fresh air into the cab, and necessitated extra vents under the roof peak. Cooling air could then be ducted down the back of the cab and under the bed directly into the engine - dust and overheating problems solved! Pick-Ups like this are instantly recognizable by the slightly bulbous cab shape and the absence of cooling vents at the rear. »


David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [ Chapter 9 - Transporters Assembled or Built Overseas - South African Transporters, Pages 61~63].

Extract from Page 61

« A cyclone air filter is usually standard, but some Double Cabs have a very unusual arrangement with a pair of ducts mounted to the rear sides of the drop gates. These take in air from the top of the drop gates and duct it into the engine through slots above the engine bay. Earlier versions of Double Cabs with this extra cooling-air arrangement are found with the standard cooling vents still in place, whilst later ones are similar to the Australian version with smooth corners. »

Extract from Page 62, referring to a British registered, South African specification, 1966 VW Kombi, illustrated on Page 61.

« Other interesting features, which are optional equipment, include the cyclone air filter (usually a standard option in hot, dusty climes) and extra air ventilation fans in the roof of the load area. An unusual after-market addition is the extra cooling vents, each with a chrome cover. They can be flapped open to allow more cooling air to be forced into the engine bay. »

[fig]

Nigel

I was just going through my factory VW literature and I found a Technical Bulletin K7 of 1963 "Oil bath air cleaner with cyclone filter for Volkswagen 1200, Transporter 1200 and Industrial Engine 122-1/2", which describes the service fitment of a larger oil bath air cleaner with cyclone primary filter.

It's 18 pages, but I'll see if I can have it scanned.

[Nigel A. Skeet]

Nigel

I was just going through my factory VW literature and I found a Technical Bulletin K7 of 1963 "Oil bath air cleaner with cyclone filter for Volkswagen 1200, Transporter 1200 and Industrial Engine 122-1/2", which describes the service fitment of a larger oil bath air cleaner with cyclone primary filter.

It's 18 pages, but I'll see if I can have it scanned.

That would certainly be an interesting addition to the information database; particularly if there are a comprehensive set of pictures and sectional diagrams included.

One wonders whether there might have been a series of similar bulletins for the later vehicles!?!

[fig]

Nigel

I was just going through my factory VW literature and I found a Technical Bulletin K7 of 1963 "Oil bath air cleaner with cyclone filter for Volkswagen 1200, Transporter 1200 and Industrial Engine 122-1/2", which describes the service fitment of a larger oil bath air cleaner with cyclone primary filter.

It's 18 pages, but I'll see if I can have it scanned.

That would certainly be an interesting addition to the information database; particularly if there are a comprehensive set of pictures and sectional diagrams included.

One wonders whether there might have been a series of similar bulletins for the later vehicles!?!

Yes, Nigel, lots of pics and detailed plans. And yes, I'm sure there were later editions of this bulletin; I just don't have them. The pictures of the larger oil bath filters on the 1200 engines look exactly the same as the larger oil bath filters on 1500 and 1600 engines.

[fig]

David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [ Chapter 9 - Transporters Assembled or Built Overseas - South African Transporters, Pages 61~63].

Extract from Page 61

« A cyclone air filter is usually standard, but some Double Cabs have a very unusual arrangement with a pair of ducts mounted to the rear sides of the drop gates. These take in air from the top of the drop gates and duct it into the engine through slots above the engine bay. Earlier versions of Double Cabs with this extra cooling-air arrangement are found with the standard cooling vents still in place, whilst later ones are similar to the Australian version with smooth corners. »

Extract from Page 62, referring to a British registered, South African specification, 1966 VW Kombi, illustrated on Page 61.

« Other interesting features, which are optional equipment, include the cyclone air filter (usually a standard option in hot, dusty climes) and extra air ventilation fans in the roof of the load area. An unusual after-market addition is the extra cooling vents, each with a chrome cover. They can be flapped open to allow more cooling air to be forced into the engine bay. »

As great as David Eccles's books are, I would take everything in them with a pinch of salt.

He states above that "cyclone filters were usually standard". In fact, M156, larger oil bath air filter, was standrad on SA buses; I've never seen a VW cyclone filter fitted to any SA bus.

And the extra cooling flaps referred to were certainly not a VW option. From the pics in the book they look like generic aftermarket vents that you would find on a truck panelvan body; likewise the "extra air ventilation fans in the roof of the load area".

[Nigel A. Skeet]

David Eccles, "VW Transporter & Microbus - Specification Guide 1950~67", The Crowood Press, 2002, ISBN 1-86126-509-3 [ Chapter 9 - Transporters Assembled or Built Overseas - South African Transporters, Pages 61~63].

Extract from Page 61

« A cyclone air filter is usually standard, but some Double Cabs have a very unusual arrangement with a pair of ducts mounted to the rear sides of the drop gates. These take in air from the top of the drop gates and duct it into the engine through slots above the engine bay. Earlier versions of Double Cabs with this extra cooling-air arrangement are found with the standard cooling vents still in place, whilst later ones are similar to the Australian version with smooth corners. »

Extract from Page 62, referring to a British registered, South African specification, 1966 VW Kombi, illustrated on Page 61.

« Other interesting features, which are optional equipment, include the cyclone air filter (usually a standard option in hot, dusty climes) and extra air ventilation fans in the roof of the load area. An unusual after-market addition is the extra cooling vents, each with a chrome cover. They can be flapped open to allow more cooling air to be forced into the engine bay. »

As great as David Eccles's books are, I would take everything in them with a pinch of salt.

He states above that "cyclone filters were usually standard". In fact, M156, larger oil bath air filter, was standrad on SA buses; I've never seen a VW cyclone filter fitted to any SA bus.

And the extra cooling flaps referred to were certainly not a VW option. From the pics in the book they look like generic aftermarket vents that you would find on a truck panelvan body; likewise the "extra air ventilation fans in the roof of the load area".

Were you referring to these extra cooling vents or some other?

« An unusual after-market addition is the extra cooling vents, each with a chrome cover. They can be flapped open to allow more cooling air to be forced into the engine bay. »

David Eccles, is by his own admission, a relatively non-technical person; being by profession, a teacher of English, at a British comprehensive secondary school, somewhere in Lincolnshire, if I recall correctly. His VW associated DIY technical activities, do not seem to go much beyond basic servicing.

There have been several technical and picture-related errors in various issues of Volkswagen Camper & Commercial magazine, of which he is editor. I have personally identified, at least two major pictorial howlers, relating to images being transposed, left-to-right or top-to-bottom! To a large extent, he is reliant upon others, to provide accurate information.

Hopefully, people such as ourselves, will apprise him of such errors, so that errata may be appended, to books and magazines.

[Nigel A. Skeet]

Whilst I was surfing the Internet on another occasion, I came across an item outlining the discrete conversion of a VW oil-bath air cleaner, into a modern paper-element air filter; preserving the original outward appearance of the oil-bath air cleaner housing. The task is said to take about 30 minutes, plus overnight curing of some adhesive cum sealant.

Howto section of drop-down menu

followed by

Convert your Oil Air Cleaner to a Modern Filter

http://www.baronvonkronken.com/