500 cfm carby (Read 1,187 times)

[sk72]

Hi all,
Asking on behalf of a friend.

Can a 500cfm carby work on a single rail type falcon inlet manifold?
Is there any head work which needs to be done?

Thanks in advance.

[Deleted]

yes they can be used for a 4L falcon - even on a stock standard motor. alot of stock cars use them - or a 350cfm.

its all in the jetting for tuning it.

not sure what you'll have to do to put it on the manifold though

[sk72]

Dec 7, 2016 5:56:02 GMT 12 @rhodesta said:

yes they can be used for a 4L falcon - even on a stock standard motor. alot of stock cars use them - or a 350cfm.

its all in the jetting for tuning it.

not sure what you'll have to do to put it on the manifold though

Thanks Rhodesta,

I will pass this on if he hasn't seen it already. 

Much appreciated. 

[mobilechicane]

Hi, thanks SK72 and Rhodesta ...have the laptop back so can ask away ...yeah.. had a 350 cfm on the motor and she ran ok...but that carby got pinched so i had to get another...decided on a 500 trying to force more air through the system...what happens is the motor fires and roars into life then just stops...like it getting no fuel until you start pumping the gas and it grabs the fuel being squirted from the top....so is it more fuel i need...bigger or smaller jets...does the head need to come off and be tested or flowed or anything like that...how do i sort this out...or...take it to who? cheers

[mobilechicane]

hi again...been watchinf videos...jet size is 74... anyone out there running a stockcar cam in their falcon like to suggest a jet size...trying to avoid spendig 155 bucks for a whole kit...cheers

[dontpanic]

Sounds like you may have a carb that wont idle and I am assumeing it is second hand not new?

The idle curcuit is completely differant to the main jets

the Idle curcuit can get blocked one trick is to rev the moter and slap your hand over the top to cause a vacume under your hand sometimes this will suck the rubbish through and clear the curcuit otherwise you will have to pull the bowl and metering block and blow everything with compressed air

Otherwise if it is not the idle curcuit check if fuel is spraying from the boosters as soon as it revs up off Idle if you look down the carb with good light you should see fuel comming from the circle in the middle of the venturi's this is the main curcuit that is feed by the jets,

a 74 is heaps of jet and the size is just fine tuneing, and unlikly to cause your issue, what you might have is a blockage in either the idle curciut or the main curcuit this could either be junk or the wrong gasket that is missing a hole in the right place for the fuel to pass through.

thats were I would start

Brendon

[mobilechicane]

thanks yep carb is new...but will check it out cheers