16 replies to this topic

[Dusky]

How do you connect vacuum advance on a twin carb? leave 1 carb blanked?? Or is there a T-piece? or should I get the vacuum @ inlet manifold?

[jpw1275]

As far as I know it's only to one of the carbs..... It's the left carb looking from the manifold end

Cheers james

[jpw1275]

But some earlier twins didn't have a vacuum take off

[Dusky]

I got 1 connection at each carb, but wouldnt using only 1 carb imbalance the whole system?

[petehuws]

I got 1 connection at each carb, but wouldnt using only 1 carb imbalance the whole system? :Pn

No, it's only after a presence of vacuum which is satisfied by one carb.  Connect to one and block the other off, (doesn't matter which).  Out of curiosity what are the numbers stamped onto the carb bodies?

Edited by petehuws, 11 June 2014 - 09:33 PM.

[Gremlin]

If you really wanted you could put a 't' piece in but is really not necessary

[KernowCooper]

Only problem with a Y piece and why is not used is if one carb is slightly  ahead/behind of the first it would cause all sorts of issues with inconsistent vacuum one carb is ok

[Dusky]

I got 1 connection at each carb, but wouldnt using only 1 carb imbalance the whole system? :Pn

No, it's only after a presence of vacuum which is satisfied by one carb.  Connect to one and block the other off, (doesn't matter which).  Out of curiosity what are the numbers stamped onto the carb bodies?

Float chamber says AUD 2140 , but dont see anything on the carb body... Where on the carb body are the numbers?( they are still assembeled and on the manifold AEG 573)

[petehuws]

luckily I still have my carbs off the car.  Carb number is here on the outer of the body close to the float bowl.  This is howing the LH side carb and numbered AUC871, the RH carb is AUC870 (on mine).  The right hand AUC870 has the vacuum connection on my setup, there is no vacuum on the left hand AUC871.

 

Edited by petehuws, 12 June 2014 - 07:13 AM.

[Dusky]

I have the same numbers( AUC 870 and 871) but they both have a vacuum

[Dusky]

Found another surprise ; the manifold was flowed

[Dusky]

is this manifold worked at?

the rough looking ' parts' are actually way smoother than the rest

Edited by Dusky, 13 June 2014 - 03:12 PM.

[jpw1275]

Here's mine that as been fiddled with... And the pistons and butterflies have been modified too

The top edges of the manifold have been smoothed aswell





Cheers James

Edited by jpw1275, 13 June 2014 - 04:45 PM.

[Dusky]

Looks about the same, you have way better pictures though How do you light them?

 

Any pics of modified butterflies etc? :) Dont know how far I  can go ( bit scared )

[jpw1275]

The sun was out , so I angled the manifold to light it up by the sun....hehe...

Il get some pictures of the butterflies and pistons for you

Cheers james