Carburettor air intakes

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Carburettor air intakes

Postby ankaili52 » Mon Sep 09, 2019 4:14 pm

Hi, I have a 1961 3.8 Mk 2, with twin 2" carbs. They are fitted with air-trumpets, and so to protect the engine from grit and other contamination I use a kind of circular foam 'sock' to cover them.
However, I have recently noticed several cars (including Vicarage restorations) fitted instead with 'short ram pipes' that have a kind of spherical grating to presumably act as a filter. These are being sold by Burlen who are the SU supplier.
Does anyone know of these, and how they compare to the traditional air trumpets in performance?
PS I tried to upload an image but it didn't want to.

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Re: Carburettor air intakes

Postby PPV » Tue Sep 10, 2019 1:49 pm

Has your car been modified to have 2" carbs? Ram pipes tend to only have a mesh unless a 'sock' is fitted so there is little filtration. If you are after some benefit then I would look at K&N filter units which tend to offer better breathing.
Paul V
Mk2 3.8
Mercedes A45 AMG
Mercedes AMG GLC43

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Re: Carburettor air intakes

Postby ankaili52 » Wed Sep 11, 2019 8:55 am


My car had 2" carbs from new, it was built by Jaguar for a racing driver, and has several other non-standard features.
When I bought it nearly 10 years ago, the previous owner had used circular wads of felt to give some sort of filtration, but my research discovered that in racing the air trumpets would not usually be covered at all. I found out that CMC were fitting foam 'socks' to cars they restored with open air intakes to filter out grit, etc. in daily driving, so bought a pair myself.
I was just wondering if the perforated chrome "shower heads" I have now started to see on some cars would be any better.
Thanks for your interest.

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Re: Carburettor air intakes

Postby piman » Wed Sep 11, 2019 5:50 pm

Hello Ankaili,

I have had a look on the Burlen website and all I can see are trumpets fitted with a mesh domed cover, these do not provide any effective air filtration.
There is not a lot of room in a MK 2 between the wings and the carburettors. However it may be possible to use the same system that Aston Martin used on it's DB4,5 and 6 cars, This was a rectangular air duct bolted to the carburettors but with trumpets fitted inside the air duct. This was then connected to a remote air cleaner using a flexible duct hose.
They also show K and N pancake type filters which is another option?
Mk 2 3.8 (long term restoration), MK1 Triumph 2.5 P.I.,2.5 X Type Estate, 564 Hymer Motorhome


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Re: Carburettor air intakes

Postby Ronniebiggs » Wed Sep 11, 2019 6:55 pm

Piman etc,

Trumpets, if of suitable radius at the flare, do aid breathing. Mesh covers, of any flavour, ruin breathing and don't filter! The amount of debris ingested by an engine without filters is quite terrifying, and forms an excellent grinding paste when mixed with fluids in an engine. In the 'old days' of Cosworth DFVs in F1 an unfiltered engine would lose around 50hp after one race due to wear caused by such muck.

The large circular paper cleaners, as fitted to 3.4 Mk2s etc, breathe well and are excellent filters. They also silence the intake effectively.

Due to limited space there's not a lot on the market that will do as good a job as the standard fitment, so you'll probably need to use stub stacks (short, radiused thingies like miniature trumpets) inside a plenum fed by a remote filter.

Jaguar 3.4 Mk2. As original as I can keep it whilst still being safe!

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Re: Carburettor air intakes

Postby 340jag » Sun Sep 15, 2019 5:11 am

I have HS8's and have fitted Pancake Air filters !
20180609_044109 - Copy.jpg

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