Where exactly does the petrol go?

[Anonymous]

@L.Lewis wrote:

But, the inlet to the carb is at the highest point on the carb. Anti-gravity petrol? It just doesn’t seem possible. It couldn’t maybe slowly drain into the cylinders, could it? But if it did that, it should drain out the line on the intake but it doesn’t do that since there’s no pool of petrol on the ground and if they did do that, wouldn’t Tractions be known for it? if I drive mine every day they start instantly with no pumping of the lever, more than a day of sitting, then I have to. The fuel can’t possibly evaporate that fast. I’ve been home recently recovering from surgery so I have time to ponder such an imponderable.

Possible answer for you Larry. My mechanic was doing a bit of work on my carb and he noted the main jet is just sitting in the tube from the float. So, fuel could leak out the joint until it reached that level, making for very hard starts. The fuel would leak through the drain in the intake manifold. In my car it was leaking quickly enough that the fuel spill was visible, but perhaps if the leak was slow enough you would only have a very small spot? Regardless, a little sealant at the joint and the car starts on the first pull even after sitting 48 hours.

[Anonymous]

Thanks, that might be the thing to look at. Both of my carbs are fairly new though. I wonder, a little jar placed under the overflow to capture any run-off might also be something to consider.

[Anonymous]

I too have been suffering from the “missing petrol” when the car is left for a while. sure a few pumps on the priming lever helps but it never fired straight away.
Non return valve fitted but not really made a difference.
Always felt the car was choked by the single carb, by the way the revs would drop at a fold in the map let alone a hill, just look at the carb dia for a 2 litre engine.
I have now fitted the twin SU carb and manifold available from the pages of Floating Power and the transformation is amazing. I have always been a fan of SU carbs as they are so easy to set up and tune.
Not only instant starting, no matter how long the car is left it fires straight away. The car now leaps up hills with no loss of speed.
I can only conclude the lack of petrol is due to the fuel bowl on the single carb sitting on top of the hot spot and heat soak is evaporating the fuel away.

[Anonymous]

That is very interesting – are there any other “standard” options for upgrading the Carb – i.e. is there an inlet manifold that may be available for a slightly larger bore.

PS – I have a few hills around me 😀

[Anonymous]

I am just back yesterday after 3 weeks of working at John Gillard’s. He has at the shop an 11BL with a brand new Weber carb on it that looks like it was made for it. John wasn’t sure where it came from. I’ve had good luck with Webers and it might just be the thing. Does anyone know who has them?

[Anonymous]

Did you get the model number of it.

Quite a few people change from Solex to Weber on the 4CV as well.

PS – coming back to the UK myself next week to pick up a new engine and gear box – my little 4CV is going to have a Gordini power house in the rear 🙂

[Anonymous]

James Geddes (was he not there when you were Larry?) supplies twin SU’s with a manifold as advertised in Floating Power

Don’t forget 1911cc ID and DS had various carbs fitted including Webber.

[Anonymous]

James Bowler was there and James from Newcastle were there. I don’t recall the other guy, maybe he was there but John did talk about him but not regarding carbs. Didn’t note the model either, damn it! I should give John a call about it. My various friends with Ds all have Webers.

[Anonymous]

James from Newcastle and James Geddes are one and the same!

[Anonymous]

Shit! I never did learn his last name. He did say how he liked twin SUs, didn’t say much about Webers or even that he sold them. Nice guy, we got on well.

[Author]

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