Unusual addition to inlet manifold

[stanley sweet]

Hope it's OK to use this photo - found it in an ad for a Fulvia. Can anybody explain the addition of the rubber tube indicated on the inlet manifold? I've never seen this modification fitted to any other Fulvia. So it's either doing something very clever and we should all have one or it's doing nothing at all. By the way, what are the bolts for in that position on Fulvias? Are they for the fitting of a manometer?

[lancialulu]

Hope it's OK to use this photo - found it in an ad for a Fulvia. Can anybody explain the addition of the rubber tube indicated on the inlet manifold? I've never seen this modification fitted to any other Fulvia. So it's either doing something very clever and we should all have one or it's doing nothing at all. By the way, what are the bolts for in that position on Fulvias? Are they for the fitting of a manometer?

"crude" balance ports that have been adapted  to take manometer tubing and when finished "closed off" with a tube which marginally shares out the 2nd and third venturi - why???
only between 2 and 3 venturi. 1 and 4 butterflys may be not synced as such. Best to use some method to find the average of 1&2 and 3&4. I use a cheap 10mm bore plastic pipe and listen to the hiss at tick over....

[stanley sweet]

The other strange thing is the addition of that long spring from the throttle spindle to something that appeared to be attached to the top of the radiator. Not sure if it's supposed to be some 'secondary return spring' for motorsport. I never needed one when I was sprinting etc because Fulvia's have enough return springs built in as it is.

[Jaydub]

Tim, it only needs a take off on 2& 3 inlet ports to balance both carbs, because if you synchronise those 2 ports, 1 & 4 will automatically be the same as the butterflies are on a common spindle on each carb. when you listen for the hissing it will change if you alter the balance screw between the carbs. Adjusting the mixture screws can change the hiss slightly also. Obviously you need even compressions, valve clearances, no air leaks on the inlet manifold,etc. on all cylinders to achieve a good setup.

[lancialulu]

Tim, it only needs a take off on 2& 3 inlet ports to balance both carbs, because if you synchronise those 2 ports, 1 & 4 will automatically be the same as the butterflies are on a common spindle on each carb. when you listen for the hissing it will change if you alter the balance screw between the carbs. Adjusting the mixture screws can change the hiss slightly also. Obviously you need even compressions, valve clearances, no air leaks on the inlet manifold,etc. on all cylinders to achieve a good setup.

sorry John you missed the point.

[carcrank]

I assume it's just an easy way of plugging two nipples that have been put there. The bore would be too small to act as a balance tube I would think.

Cheers

mark

[Jaydub]

Apologies Tim if I misunderstood. What point?

[lancialulu]

Apologies Tim if I misunderstood. What point?

Sent you a PM....

[rogerelias]

I remember years ago when I rallied a Fulvia  on night events in the Welsh Championship under 1300cc class, The local scrutineer who I never got on with, told me it could not run, as I did not have enough return springs on the throttles. This he did in front of people wondering what the car was. I argued that it had 3 springs, and only needed 2! He said his decision was final. At which point I pointed out that he was moving the chokes!!!  and then showed him the spring on each carb, and the the one where the cable was. Point made, 1 nil to me!