weber jets, one last question!

[Phil]

Ok I have 132 and 127 main jets and 175 and 145 air corrector jets for my 32/36 weber. What would be the best setup(ie. which for primary and secondary) on a stocko 1600 with extractors and sports exhaust.

[GasGem]

Some previous advise from kind people,

primary should be 140 mains and 175 air corrector,
secondary should be 140 mains and 165 air corrector.

Ben Wight

primary should be 145 mains and 185 air corrector,
secondary should be 150 mains and 165 air corrector.

Benjamin

Probably start with Ben Wright's setup and see how you go,

if you cannot get jets, like me I use a Large soldering iron and a set of jet drills, but in your case if you get drill the same size as your 145 air correction you can drill out your 127 main jet to 145, then put that in your secondary, and give that a go then if possible take a little out of your 145 aircorrection jet,

see how that goes,

Remember that the holes must be clean NO burrs of scoring keep thet drilling clean,


thanks to Benjamin & Ben Wight for jet sizes,


Cheers
Eggy

[Phil]

Thanks for the help but at the moment I can't get the equipment to change sizes etc. so I was wondering what I should do with the size jets I have - 132/127 main jets, and 175/145 air correctors. It used to run fine until I rebuilt it so I'm just trying to figure out how they used to be.

[GasGem]

you have 4 combinations,
try em all,
which ever is best,

it's all going to be a compromise,

cheers
Eggy

[Ben Wight]

Thanks to eggy for all pleasant remarks.

Phil, your jets are in my opinion wrong, but how far they are off is a question for an oxy sensor, not my guesses.

To optimise your situation, I would be jetting the primary circuit with 127 main and 175 air, and the secondary with 132 main and 145 air, however I fear that this may make the primary slightly lean, but the secondary should be pretty close to being a good ratio.

Ben Wight

[Josh]

Are these Jet setting the same for a 180 Holley???

[Phil]

Thanks heaps to both eggy and Ben for ya help.

[Ben Wight]

If the Holley 180 is the weber copy, then yes, the jets are the same style. The whole carb is identical, except it says holley on it.

[Benjamin]

Cheers eggy, but mine ain't that correct either

Last night I swapped back over to 140 primary with the same corrector in an effort to gain a little economy. It is a bit smoother, the difference between 140 and 145 is amazing, but it is slightly lean and has a couple of holes.

My question is, what should I do with the mixture screw and whereabouts should that be? Which direction is rich and which is lean?

I have got her almost running right, just need to richen primary up a little. Once that is sorted I might experiment with 155 secondary, see what difference that makes

Cheers and thanx

[Benjamin]

Did anyone else notice Carburators Australia's mistake? Correct me if I am wrong, but last I checked the correct spelling was 'Carburettor'.

Funny that even the domain name is registered with incorrect spelling!

Reminds me of a rat cousin I have, backyard or magazine mechanic calling a distributor a 'distriburator'...

Anyways, that was a digression

[GasGem]

Mixture screw, in is lean and out is rich,

if you have a vacum gauage, connect it to the hose on the bottom centre on the intake manifold,

the rule of thumb is:
adjust the idle mixture until the car runs the smoothest and you get the highest manifold vacum at idle,

Cheers
Eggy

[GasGem]

Hey Ben,

my understanding:

the smaller the aircorrection the earlier the mainjet will come into play? ofcourse too small or large will cause issues. (without considering the venturi size or emolsion tubes)

so by usung the 127 main and the 175 aircorr, it will have a small amount of fuel allowed to flow, but it will be delayed in coming out of the venturi due to the small aircorr, thus his stutter,

I would consider getting the primary correct before the secondary so that you can still drive it. But of course doing this if someone is going to floor it all the time is pointless, I understand that.

either way he needs new jets unless they have been previously drilled?

Sorry to question you,

Cheers
Eggy

[RJM]

Try Carburetor

[Ben Wight]

Hey eggy,

No, its not the air corrector jets that determine when the main system comes into action, that is the job of the booster venturis.

The air corrector jets simply meter the air that mixes with the fuel before it enters the main venturi. Due to the physics of airspeed giving a greater magnitude of friction as air speed increases, the air corrector jets flow less air as the airspeed (revs) increase, thus, they tend to slightly richen the mixture as revs increase, which is amplified when making them smaller.

An air jet is thus typically modified to alter the fueling at relatively high rpm.

Ben Wight

[GasGem]

thanks,