MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Help: Air filters and ram pipes?

Hi,
I'm fitting a pair of HS6 carbs to my engine (it's a big bore and can cope with them). However, I am a tad confused as to the best air filters (K&N or piper cross or other, and what depth/ size of filter?) and if to use ram pipes, and if so, long or short?

I've read quite a bit, but it's not that clear or explicit on the matter.

Any help will be much appreciated.

Cheers,
Grant :-)
G Hudson

Grant - It's a well-trodden path - ask the technocrats at the club - they will have the precise details.
Roger
Roger

Hello Grant,

By experience SU or Stromberg need some kind of Mini-ram at least. Look at regular B air filter, you have this kind of spacer, 1/2" thick, like a "mini ram" inside the filter housing. Those carburetters are flow sensitive and seems to be unable to deal with incoming air from all directions.

Cheers,
Jen G.
Jean Guy Catford

Grant-
A pair of stub stacks will suffice. A pair of 5 7/8” Diameter x 3 1/4” deep K&N airfilters (K&N Part # E-3190) will permit increased flow of the fuel / air charge without sacrificing protection. With proper fuel jet adjustment, when installed on an Original Equipment specification engine these larger airfilters are worth about 3 HP on their own. When attempting to build a deeper-breathing engine, they are a prerequisite. A K&N airfilter is made of 4 to 6 layers of cotton gauze sandwiched between two epoxy-coated aluminum wire screens. The cotton is treated with a specially formulated grade of oil causing tackiness throughout the cotton’s microscopic strands. The nature of the cotton allows high volumes of airflow, and when combined with the tackiness of the oil creates an efficient filtering media that ensures engine protection. In contrast, most other filtering media cannot maintain the same balance of airflow and filtration throughout the airfilter's life without sacrificing either one or the other. K&N airfilters have the additional advantage of being almost infinitely reusable so long as reasonable care is taken when cleaning them. K&N makes a cleaning kit for this specific purpose that does an excellent job. Once cleaned, they should be allowed to air dry. Because the filtering medium is made of cotton, you should not use a hair drier to speed up the drying process. If you make this mistake, the filtering medium will shrink.
Steve S.

http://www.twminduction.com/AirHorn/AirHorn-FR.html

http://www.pegasusautoracing.com/group.asp?GroupID=AIRHORNS

This should be the best...

http://www.aptfast.com/Images_Parts/Fuel_Sytem/Billet%20Stub%20Stacks.JPG

Scroll down to see what they have to order in regards to those pics

http://www.aptfast.com/APT_Parts/SU_Parts/a_SU_components.htm

james

http://www.su-filters.com/

This should do the trick
james

All,

many thanks for your input. I emailed Roger at the MGOC and he was very helpful.

cheers,

Grant :-)
G Hudson

Another option is to use long ram pipes and filter socks. You can get them at Merlin (Castle Combe), much cheaper than K&N's. If you're running HS6s then filters are probably not an issue inasmuch as they will be capable of flowing more than enough air.
Neil
Neil

Has anyone any dyno data on stacks for street use ,std. engine ? Or are they only a benefit at high revs, say 4000 plus. Whether short or long .
Thanks Sean
S Sherry

I ran a test on my supercharged MGB. First with a K&N pod type filter and then with a 1.75" ram tube. The power reading did not alter but it was interesting that the A/F ratio was .2% higher with the filter, so even K&N have an influence on mixture. I feel this shows that the pod type filter acts as a air smoothing device itself and probably gains little from a ram tube inside.
Denis
Denis4

what was found is that the shorter the ram air pipe is, the better. Also check these out. Could not get in contact with them about supplying them. Maybe someone else would be in luck. http://www.huffakerengineering.com/images/engines/SideEngine.jpg

These look ideal
james

This thread was discussed between 25/01/2009 and 04/02/2009

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.