Holley Air Bleed Modification.

[JeffMcKC]

Re: Holley Air Bleed Modification.

He has his terms wrong the wire goes in the idle fuel passage in the metering block, you bend it into a V shape and put it in the two fuel passages int the lower part of the metering block

[milner351]

Re: Holley Air Bleed Modification.

Gene had a thread on this a while back - he runs the wires in the holley on his chevelle - and got great mileage on the way to woodward with it this past summer.... the plugs were white - pretty lean for a carb, but it ran great.

[Scott Liggett]

Re: Holley Air Bleed Modification.

I drilled out the rear low speed idle air bleeds yesterday. I only went up one step on the index drill bits, since I have a couple broken bits I still need to replace.

I can't report on the improvement, or not, as the rear float got stuck and dump a ton of gas into the motor before I noticed. The plugs are gas fouled and I need to get new ones. I ran out of time to change them yesterday and am back to work for the rest of the week.

[Scott Liggett]

Re: Holley Air Bleed Modification.

I drilled out the rear low speed idle air bleeds yesterday. I only went up one step on the index drill bits, since I have a couple broken bits I still need to replace.

I can't report on the improvement, or not, as the rear float got stuck and dump a ton of gas into the motor before I noticed. The plugs are gas fouled and I need to get new ones. I ran out of time to change them yesterday and am back to work for the rest of the week.

changed out the spark plugs. Yep, they were gas fouled. Car runs better. Idle screws are now 1/4 turn farther out, and the idle is leaned out and doesn't make my eyes bleed. I had it running while I spent 10 minutes cleaning up the trunk crap and was not over come like before.

Turning the rear idle mixture screws showed the most reaction to the vacuum reading. And, all this is from one tiny size larger hole. #52 to #51 indexed drill size.

[IRONHEAD]

Re: Holley Air Bleed Modification.

did you get hotter plugs??
and if so.. was it the small drill hole change or the hotter plug that made the big difference?
I'd think the lack of missfires would have more affect on that than the hole,, but i've never played with air bleeds on a street car

[A/Fuel]

Re: Holley Air Bleed Modification.

I think that if the idle speed increased it would be directly related to the air bleeds. (he didn't say though.)

[Scott Liggett]

Re: Holley Air Bleed Modification.

did you get hotter plugs??
and if so.. was it the small drill hole change or the hotter plug that made the big difference?
I'd think the lack of missfires would have more affect on that than the hole,, but i've never played with air bleeds on a street car

I replaced the 3926's with the same. Hottest plug in the series. My car doesn't like colder plugs at all.

And, the increased idle speed was from the air bleeds.

[IRONHEAD]

Re: Holley Air Bleed Modification.

thought someone said your plugs where not the hottest ones..?

[Scott Liggett]

Re: Holley Air Bleed Modification.

thought someone said your plugs where not the hottest ones..?

I was going by my failing memory, I thought I had 3924's, but I actually had 3926's.

[IRONHEAD]

Re: Holley Air Bleed Modification.

thought someone said your plugs where not the hottest ones..?

I was going by my failing memory, I thought I had 3924's, but I actually had 3926's.

ha at least your memory had a number in it..I'd have to loook at my notes..
hows it pull compaired to before?

[Eric68]

Re: Holley Air Bleed Modification.

Not sure what bleeds you have in that carburetor now, but I would suggest that you measure out what you have both front and back, both high speed and low speed. I would like to see something like .028-.031 in the high speed bleeds and .072 in the low speed bleeds.

You should really tune with jets first for WOT mixture, then only as a last resort change high speed bleeds. If you have too much fuel down low (like below 3000 RPM) then drill and tap the IFR for a 6-32 set screw and go a little smaller. The IFR is sensitive to change .002 will make a noticeable difference.