TR2/3/3A Carburetor Identification

[af3683]

I would appreciate any help in identifying the set of carbs in the below photos. I've had these for a while and figure it's probably time for them to find another home. There is a tag on one of the two that says AUC786 and both are stamped AUC3495 on the carb body. My guess is that they are HS6 carbs but I'm not sure. Thank you.
Art

 

[charleyf]

I would appreciate any help in identifying the set of carbs in the below photos. I've had these for a while and figure it's probably time for them to find another home. There is a tag on one of the two that says AUC786 and both are stamped AUC3495 on the carb body. My guess is that they are HS6 carbs but I'm not sure. Thank you.
Art

I have a S U book that lists very many of the letter/numbers for the S U carbs. Your AUC 786 is not listed. What I can tell you is that these are "H" carbs not HS carbs. H carbs have the following 1) both float bowls are in the front 2) the choke mechanism has the long brass feature at the bottom . While the HS carbs have 1) float bowls front for front carb and rear of body on rear carb 2) choke control does not have the long brass arm below the carb body.
I can not tell what size the throat of your carbs is. To be a 6 it would measure 1&3/4" diameter. A 4 would be 1&1/2" diameter. And I believe the 2 would be 1&1/4". So H6 or H4 or H2.
Your number AUC 3495 is for the float bowls and not the body or carb I.D..
Charley

 

[af3683]

I have a S U book that lists very many of the letter/numbers for the S U carbs. Your AUC 786 is not listed. What I can tell you is that these are "H" carbs not HS carbs. H carbs have the following 1) both float bowls are in the front 2) the choke mechanism has the long brass feature at the bottom . While the HS carbs have 1) float bowls front for front carb and rear of body on rear carb 2) choke control does not have the long brass arm below the carb body.
I can not tell what size the throat of your carbs is. To be a 6 it would measure 1&3/4" diameter. A 4 would be 1&1/2" diameter. And I believe the 2 would be 1&1/4". So H6 or H4 or H2.
Your number AUC 3495 is for the float bowls and not the body or carb I.D..
Charley

Charley,
Thank you very much for all your help. I just measured the diameter of the throat with my tape measure several times and I get 1 5/8 !! Very strange.

 

[NutmegCT]

Hi Art - take a look:

Search AUC 3495 | SU Carburetters

Su Carburetters are The Worlds Sole Manufacturer of Genuine SU Carburettors, Fuel Pumps and Spares.

sucarb.co.uk

Tom M.

 

[CJD]

They look like H6 to me.

 

[charleyf]

Charley,
Thank you very much for all your help. I just measured the diameter of the throat with my tape measure several times and I get 1 5/8 !! Very strange.

Actually if you measure the outlet( engine) side you will get the 1&3/4".
Also the body number is 6040 as shown in the attached pic.
It is difficult to determine why the H6 carbs have so many different identifying numbers( the number on the tag on the fuel bowl). But there can be a number of variables between carbs. Such as the rotational angle of the fuel bowls, as they need to be level. And different motors mount them differently. Then the needles and possibly the fuel bowl caps.
Charley

 

[Hamish Racing]

They look like the same H6 su’s that came off my 1959 3a

 

[Scargo]

The four bolt mounting flange gives it away as an H6 (1-3/4”).

SU’s are sized in 1/8” increments.

H1 = 1-1/8”
H2 =1- 2/8” aka: 1-1/4”
H4 = 1-4/8” aka: I-1/2”
H6 = 1-6/8” aka: 1-3/4”
H8 = 1-8/8” aka: 2”

 

[charleyf]

The four bolt mounting flange gives it away as an H6 (1-3/4”).

SU’s are sized in 1/8” increments.

H1 = 1-1/8”
H2 =1- 2/8” aka: 1-1/4”
H4 = 1-4/8” aka: I-1/2”
H6 = 1-6/8” aka: 1-3/4”
H8 = 1-8/8” aka: 2”

The HS6 has a duplicate mounting flange. As I would guess that each of the similar HS models.
So with the tag on top of the float bowl showing a 786 just what car were these H6 carbs set up for?