supercharger fueling

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crappycresta
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supercharger fueling

Post by crappycresta »

where do i start ,to begin with i had trouble starting my car ,removed the supercharger ,shock horror there was a pool of petrol in the valley of the inlet manifold,put it down to over fueling while trying to start the engine,
anyway started the car ran ok but needs to tweek the timing,removed the charger again ,and yes fuel lying in the valley,if i turn a corner with the car the fuel will surely surge into no 8 or no7 cylinder, i now have drilled the bach of the manifold so that i can put a tap on it to see how much fuel is not going in to the cylinder,the only thing i can think is to gradualy weeken the mixture until there is no fuel present.
worried .

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JP.
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Post by JP. »

To start with...
How much fuel pressure do you run on the carb side ( measured) ???

What fuel pump and regulator ????

If thats oke then float hight settings ???
'73 Ford Capri. 3.5 RV8, Magnacharger 110 Supercharger, Merlin F85 Heads, Water/Methanol Injected
'73 Ford F250, 6.7ltr V8
Building a GT40 mk2

crappycresta
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fuel

Post by crappycresta »

hi i have a carter fuel pump and regulator set at 2 psi,this should not be enough to overcome the needles, ? have not run the motor since mothboling over the winter ,but im sure gauge on the carb read 2 psi. do you think i should adjust the float height ,? i have checked the height and they are at standard height.
worried Al

JP.
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Post by JP. »

The pressure should not exceed 6.5 psi. Floats should be set to the factory spec of 7/16, (see owners manual) (download here)( its on page 8 ) . Needles & Seats can be clogged with debris, not allowing them to close. They can be cleaned and checked when the float level is being verified. Floats can be sinking due to a leak. Verify floats are free of any fluid by shaking the float, or submersing it in a safe, non flammable fluid.

With todays fuel quality carbs get clogged within weeks.....
'73 Ford Capri. 3.5 RV8, Magnacharger 110 Supercharger, Merlin F85 Heads, Water/Methanol Injected
'73 Ford F250, 6.7ltr V8
Building a GT40 mk2

crappycresta
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fuel

Post by crappycresta »

now i am more worried,is there an addative thet can be used to stop this from nackering my carb ?
worried Al

bigaldart
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Post by bigaldart »

With a blower motor it is not unusual to see puddles in the inlet manifold when only running for a short time. When the engine is run and heat soaks properly these will all evaporate as quick as they form. Hence when on the road you will only have vapour in there so no problems getting a fat cylinder. It only needs the slightest blip on the throttle when you shut it down and it will look like loads of fuel in there if the motor isn't properly warm. I wouldn't worry about it unless it misbehaves when up to temperature on the road.

Alan

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topcatcustom
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Post by topcatcustom »

:whs from a few months experience!
TC

crappycresta
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Post by crappycresta »

thanks for that ,it makes sense,i will run the engine up to temperature,i feel a bit better now cheers
not so worried Al

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Ian Anderson
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Post by Ian Anderson »

Fit a manual switch on the fuel pump and once you have you car in the garage turn the pump off and let the carb "empty" and motor die.

It helps stop the varnish stuff clogging the holes etc.

Once you know how long it will run before dying click the switch 100m out or whatever

Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

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