BJ7 Carb Drama

[BG 62AH]

Curious about these carbs. I have been trying to hook up a new vacuum advance copper tube from the dist to the port on the carb. But I am running into an issue. The tube is too short.

The port for my car is on the front carb (behind the primary fuel feed line in the picture). After encountering this, I have studied other 7’s and they all have ports on the rear carb. Also, the fuel line set ups look slightly different than on other cars.

Anyone run into this? Are these replacement carbs? They are in very good condition and the car runs good, but I have been using a flexible hose for the advance (which I don’t like).

Any background or suggestions are really appreciated.

Thank you.

 

[Healey Nut]

Go to a HVAC supplies wholesaler or find a refrigeration technician and get a roll of cap tube (small copper tubing) 1/8” diameter . Cut it to the length you need and install , job done .
You will still need the rubber connectors at the ends .

 

[bob hughes]

I have a BJ7 and I have to say that the Vacuum port on mine is on the rear carb. Also you seem to have a balancing tube that I do not have, very strange.

I assume that the carbs are 1.75 inch jobs - HS6's of some sort but I do not think that they are the original carbs.

I have just looked up the HS6 body in the SU carb spares book and strangely enough it shows a diagram of an HS6 body with what looks to be a take off on the body and it describes a LH and RH interconnection, but not sure if this is referring to the spindle set up or this balancing tube.

You have me intrigued now, I will try and follow this up.




Bob

 

[bob hughes]

I have been in touch with Burlen Carburetors and it would appear that there are variants on the HS6 body, though the book does not indicate this, depending on what car was being supplied, inlet manifolds etc.

Their first question was - about the fuel feed between the float chamber and the jet - I assumed that it was of the flexible pipe feed with the jet head incorporated and fixed into the bottom of the float chamber with a stuffing gland, just like my HS6's, it is not clear from your images.

Then we discussed the balance pipe take offs. Eventually they said that the carbs were off another type of vehicle, they did not offer a suggestion as to which one as there are many vehicles using HS6's, I assume that there is a balance pipe because there were two separate manifolds on the original car! what ever that was.

Generally with most of the big Healeys there is a gallery inlet manifold which balances the carbs - a Tri carb is the exception which has a balancing pipe connecting the manifolds and the BN1 and 2s have a balancing pipe connecting the carb bodies.



Bob

 

[steveg]

Anderson Moment, page 153 clearly shows the vacuum pipe going to the front carb.

 

[BG 62AH]

Thank you for following up on this. I really appreciate it. This is the first Healey that I have worked on, and it came to me in very rough shape. I rebuilt the carbs a while back not knowing what the original BJ7 set up was.

It does not surprise me that these carbs may be replacements or off of another car, as I had a few other similar issues along the way. After studying pictures of other cars. I have not seen another BJ7 with a set up like this.

The carbs are actually in very nice condition (particularly compared to some of the other parts that needed restoration), and the car does run really well with them. I think at this point the plan will be to make a special vacuum advance pipe (as suggested above), and go with them as is. The current budget is not allowing for a new set of carbs.

I appreciate all of the help, thank you.

 

[bob hughes]

As a suggestion

Measure the route that the pipe will take then contact your spare parts chappies - Moss I guess, and find out what they have available, it may save you some effort.

Just looked at your layout again, just for interest, I ran my pipe around the rear of the rocker cover, it makes the removal of the cover a bit easier. If you do this with the standard pipe you will not make the front carb.



Bob

 

[BigGreen]

SU tech information here https://sucarb.co.uk/

 

[steveg]

Suggest using house wire to dummy up the pipe. Clips at arrows.

 

[BG 62AH]

Great suggestion, thank you, I appreciate it.

 

[Patrick67BJ8]

Curious about these carbs. I have been trying to hook up a new vacuum advance copper tube from the dist to the port on the carb. But I am running into an issue. The tube is too short.

The port for my car is on the front carb (behind the primary fuel feed line in the picture). After encountering this, I have studied other 7’s and they all have ports on the rear carb. Also, the fuel line set ups look slightly different than on other cars.

Anyone run into this? Are these replacement carbs? They are in very good condition and the car runs good, but I have been using a flexible hose for the advance (which I don’t like).

Any background or suggestions are really appreciated.

Thank you.

Any Hardware store has the copper tubing by the foot.