Air Bleed Alternatives

spinman_1949 said

So the 340 is running pretty good. But idle seems rich. Not going to try to drill and tap the 4150, so I decided to pop for a quickfuel SS vacuum secondary. Now I can tune easily with removable air bleeds.


So now the trial and error begins. And since it is a 4 corner idle circuit, I will need 4 air bleeds for each size I want to try. That is about $20 a set.

My question is. Why not use brass screws and drill. Or even nylon screws and drill? Or if threads are tapered at bottom the hole, brass set screws drilled? Or cap head screws that are stainless steel? Do air bleeds have to be brass?

Thoughts? Ideas?

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It seems rich? How can you tell? My point is, you really can't tell for sure with out some other tools (like a wideband). I would leave the bleeds alone until you can tell for sure what you are doing with them. In other words, don't mess with them until you install a wideband...even then its hard to get a good read on what they are doing. The wideband on my car works well at WOT, but at idle it is erratic. If your carb is really rich at idle, you might need to put in a smaller IFR.

Air bleeds are a good fine-tuning tool, but if you don't know what you are doing you could really screw up your carburetor. Here is a good read if you have time.

http://www.hotrod.com/how-to/engine/tuning-with-air-bleeds/



If you are still in the market for bleeds, Jegs has them for under 5 bucks a pack. You can also by blanks and drill them to whatever size you want.