XJ6 & XJ12 Series I, II & III 1968-1992

Overflow on carby help! Please

Old 06-30-2014, 06:05 AM
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Default Overflow on carby help! Please

Hi all. I am doing up a old Holden and turbo charging my Holden red 6. I am using twin 2" SU's of a Jag.
I am wondering if the overflows that come out the top of the fuel bowls are actually needed? I would like to blank them off. Will this cause me any problems? I have seen SU's without overflows? Why are they needed on these? And silly question I know, but where does the fuel overflow to on a jag?
I know i dont have a jag, but your help would be appreciate!!
Old 06-30-2014, 06:25 AM
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Sounds like HS style carbies.

The overflow is just that, and a breather as well.

On the Jag, and others, it had a hose attached and dangled down so the overflow ran on the ground. Greenies did not exist in those days.

Without that spigot I reckon the float bowl will have breathing issues, and in the event of a needle/seat failure, the engine will fill with fuel very quickly.

Even the older HD style, had a breather, via a banjo bolt dead centre on top of the bowl, and special fibre washers, that also held the bowl lid in place.
Old 06-30-2014, 06:30 AM
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Default Red Motor

For those of you not familiar with Holden engines,a Holden "red" motor is either 186 or 202 CI straight 6.
Overflow on carby help! Please-_1781119500picture065.jpgOverflow on carby help! Please-7799636330_968a1f51fa_z.jpgOverflow on carby help! Please-enginephotos090325031.jpgOverflow on carby help! Please-red.gif

Hi Randal,Welcome to the forum.
First off an intro in the new member area will get you started.

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

Then repost your question in the XJ6 & XJ12 series 1,2 & 3 forum,plenty of people there will jump to answer your question.

XJ6 & XJ12 Series I, II & III - Jaguar Forums - Jaguar Enthusiasts Forum

I think the 2" su's are HS8 carbs. I would think you would want to retain the overflows as excess fuel if a float needle sticks will exit the overflow and not be sucked into the manifold
Thanks Grant,you cleared that up better then I could.

Last edited by o1xjr; 06-30-2014 at 06:35 AM.
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