Air bleed question

Should I just buy the Quickfuel kit or get the blank deal and drill my own with a pin vice? I my question should be are the "store bought" bleeds sized correctly or are they like main jet kits that you have to check sizes before you use them.
Putting a wideband in the car this winter and I want to be ready to tune my bleeds after I get some accurate fuel curve readings.
Thanks
Gus

I always pin gauge everything. They can be all over the place.

I just bought a bunch of small size and drilled them. Also made a fixture out of a piece aluminum to hold bleeds and ifr's while drilling.

If your carb. has the screw in removable #10 air bleeds now I would be tempted to buy the pin vice and the small drill bit assortment, #61 to #70 and maybe the bigger drill bit kit from #1 to #60 and see what your current bleeds are, once that is figured out either buy some blanks or the next size bigger bleds and next size smaller and test, test, and test some more to get it exactly where you like the tune up
I ended up buying a batch of 100 # 6 brass set screws and started drilling and tapping the fuel feed channels(idle and transition circuits) for those size set screws and drill them to the size I wanted and found out exactly what the motor wanted judging by the old Butt dyno and the wide band, I now tune for lean(14.8 AFR or leaner) at idle and at light part throttle cruise up to 2500 RPM now at 3500 Ft. elevation on Oregon 91 octane pump swill

This is what I did.

I seen a drilling fixture with blanks for sale but I cant remember who sells it. I have a Quickfuel 1050 4150 style carb and it's lean according to my plugs. When I install the wide band I'm sure I can get it where it needs to be because everything is adjustable on this carb. I've got a few chunks of aluminum that I could make my own drilling fixture but that other deal comes with blanks with a small pilot hole in them.

Gus

I just buy the Holley 10 Pack of #23 air bleeds Holley 126-23-10 and drill them to the size I need. Already having a pilot hole makes them easy to drill.

I'd suggest taking the carb apart first and writing down all of the jet sizes including the air bleeds, emulsion jets, PVCR behind the power valve, idle fuel jet if it has them, etc.

Once you know what is in there then you'll know where to start. A lot of the tuning on a street car is done with the idle circuit so you probably only need some idle jets. Personally I wouldn't mess with the air bleeds until you really know that you need to make a change there. You should be able to solve 90% of the issues with a carb by tuning the idle circuit and the main circuit. Sometimes you need to change the PVCR.

That's the plan Andy. I'm changing the baseplate on my carb and when I do I will record all my current settings and pay close attention to the T-slits and make sure every thing is correct. I deal with EFI cars all day for a living but it's the same thing just a little more primitive with a carb

Gus

Unless you buy BLP's pre-drilled air bleeds, drill your own. The QFT/Proform air bleeds must be drilled by blind monkeys.

One problem with DIY: you don't know exactly what you have, so another size = no relationship.
With that small hole, any scratches etc. + length of hole itself (tapered entrance and exit will change when you drill) all affect flow.

Not sure at whom this is directed, but I...
- buy my own BLP or BG blanks (BG carbs use a smaller head that fits into a recess, instead of sits on top)
- have an exstensive set of drills which are measured so I know the actual sizes, not what they are supposed to be
- drill my own using an air bleed fixture on my drill press for consistency

I can't speak for any other DIYer, but I know what I have. And it is far more accurate & consistent than I have seen with some mass-produced carbs as mentioned previously.

x2

How about giant Panda Bears ?

I use BLP bleeds and they measure nutz on plus are smaller and either stamped or lazer etched for the sizes...........

I just buy them, blp does have nice, easy to read stuff for sure.

I have never been able to actually get totally myopic about size variances, unless it's like a miss print where something is crazy off.

I'm usually just either going bigger, or smaller, till it's as close as I can get it. So perfect sizing doesn't really bug me. Besides, after tuning on the dyno where at least things are consistent. The in car results always seem to want more fuel, or changes in the whole cure because of scoops, or heat ect.
Then factor in the time to change things, get the car cool, and try again, the air has changed again.

I suppose a PS, or comp tuner would sweat all that, and have a sure fix for everything, but getting to the edge of a tune where .001 difference in a bleed would matter with carbs seems unattainable to me . For me it's make the curve safe enough not to do too much detonating on shifts, and clean on the top end.

Measured ID does not entirely control flow rate.
ANY disturbance to the entry/exit taper (angle, length, finish) factors in.

On the plus side, the elasticity of a gas (air) should mean a closer match than incompressible liquid (fuel).

They look twice as nice as the others but they are very reasonable.
Too bad I live in Ohio and I have a limited weather window to get all this new stuff done and tested But when I see what mother nature has done to the world lately I'm lucky to live in Ohio

Thanks for all the info so far I need to get my carb apart this weekend and see what I have

Gus

Yeah the BLP stuff is super high quality. If you are going to buy bleeds and jets I'd highly suggest using BLP parts.

The beauty of the WB and tuning a carb is that it's damn near endless and even a .002 difference is a BIG jump and can shift the "curve" quite a bit and I test this a LOT weekly on the street. I did a 2-circuit 1150 for a 3400 lb pump gas Chevelle and it made 950+ hp on 93 but this is a Pettis max effort deal and on the dyno it made the most power w/100 Holley jets and .067 idle bleeds with .026 highs. They started w/95's and .028 high bleeds and after the above changes the curve was very nice he said..........I've gone from .037 ifr's to .042's in my 1050 Dommy and from .063 idle bleeds to .076's and everything in between and it changes in every area from idle to peak power/rpms. Same w/emulsion jets, high, low, 1 or 5 and their sizes open up a whole other world of tuning. And the biggie on the street and even on some race cars to keep em clean is the right size t-slot jets and on my car a .055 get's me the cleanest cruise/transition like in the 13-14's and a big jump to .070's made it unhappy in the 9-10 afr range..........FUN STUFF.............

I bought everything to drill my own blanks.But having 2 carbs makes it a PITA and just buy the Holley kits.

http://www.jegs.com/i/Holley/510/126-28-10/10002/-1

What I really dislike is when you can't read the stamping on a jet or bleed even with my reading glasses and a magnifying glass

Haha. I know what you mean. You have to get the light just right across the number.