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Carburettor stud


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Hi Guys,

Car Triumph Spitfire 1973 Mk4

I need some advice - please take a look at the picture I have circled the lower stud on my twin HS2 carbs it as broken off its the stud that attaches to the manifold.

I have been told that there has to be a correct balance of heat going equally into both pots on my carbs. Can this be reapired by crafting a tube of metal then welding onto the broken stud or could I just chop the other one off?

Many thanks
Phil  :)

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Hi All,

This is a reply from a Spit owner from another forum site "I checked the temperature of the water by measuring the top of the radiator, it was at 75 DegC, I then checked the top of the manifold where the water jacket passes through this was also at 75 DegC. I checked the exhaust manifold temperature, the car was at idle and its about 7DecC ambient. The exhaust measured approx. 250DegC depending on where I measured.

I then measured the temperature of the inlet manifold at the top of the aluminium support, my initial measurements gave me 110DegC but it was unstable. I guessed this was due to the size of the measurement area covering some of the exhaust manifold and falsely increasing the reading so I moved in so that only the aluminium of the inlet manifold was being measured. This gave me a lowest reading of 85DegC and was a bit higher in some areas.

I do not know how this would affect the petrol vaporisation but I would think that if this aluminium heat transfer part is not present this temperature will drop significantly and could affect the fuel air mix balance especially when the air velocity is low at idle.

Clearly this is not going to be a major factor and the engine will still run fine, but since this is a support part as well, if you have the part and can refit it it seems like it would be worth while.

Looking at the fuel enrichment circuit return spring on my car it is clipped onto a small hole in the manifold.

Do you think that there is anything in it??


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