MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

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 - which carbs

high guys how do i know/find out what SU's are on my 1976 mgb gt, in terms of hs4, hs6 or hif.
thanks
john
jr williamson

4's have a 1-1/2" throat, 6's are 1-3/4' throat. HS's have the float boal mounted on the side. If there original they are likely HIF's
John H

The easiest way is to look in a Moss Motors catalog. This should give you an idea if you have HS or HIF carbs. The HS carbs have external float bowls. The HIF is an internal float. As for if they are 4s or 6s, you can tell by the carb mounting flange. The 4s have a two bolt, diagonal mounting. The 6s have a 4 bolt square pattern.
I hope this helps some.
John
The MGDoc
john

John,

the 1976 home marked car was originally fitted with HIF 4 carbs. They have integral float chambers (underneath the body) and are fixed to the inlet manifold with two nuts on each carb. The HS 4 carbs share the same dimensions but have the float chambers mounted to the front and rear aside the body of the carb. Although the HIF 4 is the better coice, some drivers do not understand them as good as the older HS 4 modells and change for the older version sometimes.

The HIF 6 or HS 6 carbs are a bit larger and have a different flange with 4 stuts/nuts for each carb and a special manifold is needed to mount them.

If you can post a pic of your carbs here it would be very easy to answer your question precisely without any estimation what might be fitted to your engine :) .

Ralph
Ralph

thanks guy looks like it a set of hif.
john
jr williamson

HIF might be slightly better than HS from a mixture management or pollution point of view, but they have a number of features which render them less easy to live with. Such as the float chamber lid at the bottom, separate enrichment valve which can block and leak, poppet valves on the butterflies, to name but three.
Paul Hunt

This thread was discussed between 15/10/2008 and 21/10/2008

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now