Jose sorry but Glyn is dead accurate. Jaguar was no stranger to pancake type filters although they used screen mesh which was normal for the day. Filtration is only one of the reasons they changed to better routing of the air flow. On the 120 and 140 for example the pancake type filters had a very adequate supply of cool air from the wheel areas. With the uni-body cars like the MK1 (2.4,3.4 saloons) that supply ended. The MK1 and early MK2 drew their air from the oil bath filter under the LH front fender (wing). In fact the "filter" that was referred to in a few posts was in fact just a silencer. It had no element in it and simply controlled noise. Lastly the pancake filters on cars like the MK2 and 'S' type are not suited to provide cool air. They provide very hot air in most driving which is very counter to proper performance. The filter system on the "S' would also be a poor system with the extension duct left off. Even with the later MK2 cars the large filter housing has very long trumpets reaching out for clean cooler air. As a last comment with the blend fuel these days there are more cases of vapor lock when hot. These occur more in cars with non standard filter arrangements in our experience. Jaguar did do testing and if a couple of boy racer filters would have done the job the cars would have come with them to keep cost down.

 

Dense air is good for power. Cold air gives a better margin against knock.

Warm air helps fuel vaporisation and reduces icing.

The argument goes that, in general, under bonnet air isn't so hot when a car is running at speed and, in consequence, cold air collection gains little. However, that's in general and the Mk2 family (and series XJs) have particular under bonnet air flow characteristics. We need some measurements of air temperature to clarify. I'd take action to stop flow under the radiator and allow air to escape from the engine bay.

A cold air collector should be positioned to avoid air carrying particles, otherwise the filter becomes dirty and defeats the objective of getting more kg of air into the engine. Is under the wing a good place for that?

For a better flowing filter, I'd consider how I could install a bigger paper area before changing from paper.

 

In simple terms the method used to increase media area is more pleats in the paper or similar. That has it's limits after which you require to increase the physical size of the housing so that you can fit a larger filter element.

My Mercedes, as an example, has twin cold air collectors carefully positioned to reduce particulate capture, twin convoluted pipes & two huge filters that fit in an airbox that covers most of the top of the V engine & then feeds the MAF.

Some early cars used a little flap on the aircleaner housing that you could switch from winter to summer to handle Peter's icing concerns. But that is old hat by modern standards.

One should remember that dense air is good for power. But if you choose not to use that extra power you enjoy improved fuel consumption.

Picking up inlet air from the exhaust manifold will never be a good idea. Typical manifold temperatures range from 300 to 500 deg C or 600 to 930 deg F, you can still experience temperatures as high as 1200 deg C or 2200 deg F driving flat out. Manifolds glowing cherry red/orange.

Sorry I did not get to the propensity for knock as it is somewhat outside the subject at hand but correct nevertheless.

 

Peter on the MK1 (SIC) that was about the only place the oil bath filter would fit. THe comment about speed and temp is mostly accurate but how many of these cars do road trips now. Lots of in town and in traffic driving.

 

Indeed, one of the most difficult requirements in engineering design is that everything fits together without having two (or more) components occupying the same space.

 

Typical Benz Intake system, cold air collectors, airbox containing filters & feed to MAF. Then feeds variable length intake manifolds/runners. Sorry to use a Benz pic on a Jag forum but I happen to have it & mention above..

 

Odd why the intakes are up so high where all the hot air and bugs are, I would have thought they should be down a lot lower.

 

My Mk2 has the misfortune of the Cooper's frying pan air filter. Why make pretty aluminium cam covers and then cover them with a tin frying pan? One thing you find with this arrangement is that two dark 'discs' form on the paper filter directly facing the ends of the intake trumpets. Hopefully that means that most of the larger particles exit the trumpets and go straight on, blocking only a small fraction of the filter. Of course it's not totally impossible that most of the air goes through that small disc as well and the rest of the filter merely occupies space.

A while ago we discussed the different static spark advance that Jaguar specified for oil bath and paper filters. Did they specify different values for the paper filters depending on type and where the air came from?

 

Been this way on a number of generations of engines. No bug issues. Filters clog evenly. IATs are beautifully cool. You can monitor them on dash if you know how to. Remember these are low nose cars. (look how deep the rear of the engine is into the car body). On the S Class they are set lower with its higher nose. Go much lower & you would be into radiant heat off of the road surface. The engines are 90 deg V's with balance shafts. V6, V8, V12. Quadcam. Benz knows what it's doing.

 

OK, low nose cars, makes sense.
That's one of pet peeves, people who call themselves engineers and don't know what they're doing.
I am not an engineer, but I can look at someone's design and pick holes in it, if there are any.
I don't care who engineered it.

I think the English create more blunders then the German's do.
If something is not designed right with the English, they will try to add things to help it along, and in the end, it will work, but not after it has become so complicated and almost impossible to service.
The Rolls Royce Silver Shadow is a perfect example of this.
I don't feel that the German's do this.
I think they make more of an effort to get it right the first time with out making it needlessly complicated.

 

I’m English and an engineer so I’ll rise to the bait. I’ve a wide engineering background and have worked with engineers in a lot of different areas and from most countries in the world My opinion is that the differences you mention are far more a result of economic, social and political factors than the engineers involved in their design. Where the talents of the engineers differ, they also are more a consequence of the environments in which they work than anything inherent. This is a subject that I could write a book about, but I’ll limit myself to Jaguar.

William Lyons is often slated for his meanness. We’ve all heard the stories that when Ford got inside the Jaguar factories at Browns Lane and Radford they found cars and engines manufactured with tools that Lyons had bought second hand decades earlier from Humber and Standard. OK Lyons hadn’t invested, but where were Humber and Standard at that point? Jaguar was still alive, at least in part, because he hadn’t borrowed money from banks. Neither UK government nor UK financial institutions are at all sympathetic to UK manufacturing. The situation is quite different in Germany and most of the rest of the world.

Lyons had to be equally frugal with his staff. Rudi Uhlenhaut, technical director of Mercedes, could not understand how Bill Heynes, his equivalent at Jaguar, could possibly deliver such products with such a small team of engineers. Mercedes had more engineers working on their racing programme than Jaguar had in their entire company. You see the same story over and over again across UK manufacturing: a few engineers, no budget, and equipment that’s a hundred years old. And all thanks to the government and the banks.

Arthur Wellington (the celebrated 19th century American civil engineer, not the British general) wrote that the art of engineering is to do for a dollar what any bungler can do for a whole lot more. On that basis, British Engineers are pretty good.

As for the triumph of development over design, that's where an army of engineers come in. I'd suggest the Porsche 911, the Bosch spark plug and even the VW Golf are good examples of German designs that started out basically not very good or severely flawed (sufficiently long ago that most have probably forgotten), but persistence and development turned them into the world class products they are. Rolls-Royce went through a similar process with the Shadow, but with relatively few engineers and little budget, By then R-R was a financially stretched aero-engine company and car making was a nuisance legacy activity.

 

Rudi Uhlenhaut & team were great. I have a high level of sympathy for Bill Heynes. He was the first qualified engineer hired by Lyons/Jaguar & worked with a ridiculously small team of blokes that were not qualified but learned on the job & were endlessly busy as a result. For years Jaguar operated without a qualified engineer on staff. Tiny Aston Martin had more engineers than Jag. Dudley Gershon, Tadek Marek, John Wyer, Harold Beach et al. and even WO Bentley/Willie Watson doing pre Marek engine design.

The early 911 was nothing but an up engined Beetle with a swoopy body. Engine hanging behind the rear axle creating a monster pendulum & diabolical, terminal understeering handling ~ drive by throttle. It is indeed remarkable what they have achieved today with the flawed layout. The Cayman/Boxster designs are far better with their mid engined layout. The 911 has become a cult car that they are scared to change too much. I would have a Cayman R long before a 911. IMHO why they limit engine size & power in the Cayman/Boxster design. They know it would be a better car than the 911.

 

Just to add a red herring to this thread I thought people might be amused by what I did to my 1967 Mk2.
I do not like the original pancake filter as it impedes access to the engine, which I do like to look at.
I also wanted to draw cold air

I used an oil bath filter housing as used on early cars and modified it to fit a FRAM CA148 filter. This I fitted in the left front wheel well as Jaguar did. The work is shown in the attached file and initially I used a standard filter/silencer that came with the as shown in the attached document. However I now run with a piece of 3" PVC drain pipe covered with sound damping material and this does not seem to be any noisier and gives greater access to the cylinder head area.

Picture shows how it looks now

 

Interesting. Thanks for sharing your quest for cold air.

 

BSM, very nice work!

 

Bruce, This may be a silly question, but what exactly is there inside the AC Delco silencer? And is it more effective than a simple piece of pipe? I'm asking as most non-supercharged systems rely on the complexity of the inlet system, the air cleaner box and the nozzle on its inlet for noise suppression.

 

In reply to your question Peter it is a large box with a round paper air filter inside. That is it. You can no longer buy the oval air filter that goes in it instead you have to buy a round one then squash it flat so it fit inside. I thought I had a photo of the constituent parts but cannot find it but I have this taken from the parts manual.

 

Peter ~ see post 2

 

Thank you everyone, but we actually have two different animals here, though they have similar external appearance: a filter in some later cars and a silencer in early ones. I understand that in later cars, the oval section box is a container for a paper air filter. However, for the cars with the oil bath air cleaner, my Mk2 parts book describes the box as a silencer. In his pdf, Bruce also calls it a silencer. In Glyn's photo of the green car above and also in the photo in Bruce's pdf, you'll see silencers. With these, there are no clips for taking the end off the box for filter changing and the inlet to the box is in the end wall rather than (most often) the side wall.

I wondered what was inside the silencer version. Bruce mentioned that swapping it for straight pipe had no consequence for noise, which didn't surprise me. After all, nowadays, only cars with superchargers have any extensive attempt at silencing the inlet and that's usually by tuned resonators. They rely on the air filter box and the nozzle on its inlet. If the silencer we're discussing here is anything like an exhaust silencer, it may well cause a pressure drop.

 

Peter the Foundation is fortunate to possess one of the very first MK2s. It has the oil bath but have never looked in the silencer box----yet. When you tap on it it sounds very hollow. Will report back some time soon.