• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Carb Types

Share this page

5

58_BN4

Guest
Guest
Offline
Hello All, Cannot identify the two "as-removed" carbs I have - dirty, etc. Bore-at-manifold appears at approx. 1 5/8 inch dia. Can anyone tell me how to determine HD6 or HS6 or H4. Thanks.
 
I think that you'l find that the ID of the carb is actually either 1 1/2" or 1 3/4". The last digit of the SU model number depends on this, and is 4 for 1 1/2" carbs and 6 for 1 3/4" carbs. (The formula is to take the carb size in inches, subtract 1", and multiply the result by eight.)

On H-series carbs, the fuel flows internally from the float bowl to the jet assembly, and is contained by cork seals around the jet. These can be replaced with o-rings for a better seal.

On HS-series carb, there is a syphon tube from the float bowl to the bottom of the jet.

HD-series carbs have a larger, more complex lower jet assembly, which uses jets having built-in diaphagms.

The Burlen website (referred to in the first reply) uses the "AUC" numbers rather than the classic SU model numbers. If am reading it right, your carbs are probably HD6s ('58 & '59) or possibly the earlier H4s, if your car is actually an earlier one, but was first registered as a '58.
 
:savewave:

Great site, BIG GREEN. thanks for posting.--Keoke-- :thumbsup:
 
As usual, great info - I believe there are "AUC" numbers on the bowl, I will spend some time with the supplied web-site - THANKS
 
Back
Top