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 Post subject: by pass air
 Post Posted: Thu Aug 30, 2012 8:45 pm 
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After reading RB1's post I got thinking #-o ...I have such a large hole to get the blades closed enough so the T-slot is close to where it's supposed to be it may be causing issues with the overall idle. Now running on E85 the idle is not to where it was with my gas carb and wanting to get it there if possible.
So that being said I drilled holes in another set of blades where we usually do and another one on the other side of the throttle blade. Not doing anything else it idled better but was richer than what it was before and needed to turn the mixture screws in and would still almost stall when I put it in gear. So I went back to my original IJ and IAB that Mark set for me and had to turn the mixture screws out to 1 1/2 turns to get it to idle like I wanted..So there must be a limit to the size of hole that you can drill where we put them and if more is needed you may look at drilling another on the other side of the throttle shaft.
You would not believe the difference it made on the way it idles and comes up on the converter!!
Does anyone have an expiation for this???
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 Post subject: Re: by pass air
 Post Posted: Fri Aug 31, 2012 6:00 am 
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FYI,
BLP can correct the TSlot locations, or buy a Quickfuel body. Bruce has a pretty good deal on them.


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 Post subject: Re: by pass air
 Post Posted: Fri Aug 31, 2012 9:18 am 
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It may be if you get it too close to the t-slots it pulls fuel through the blade holes if it gets large enough.


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 Post subject: Re: by pass air
 Post Posted: Thu Sep 06, 2012 2:54 pm 
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Im going to try this on a friends 4150 850 quick fuel carb on his bracket car.
I piggy backed two 10-24 set screws the inner set .070 and the outers .060 to see how this will
work as another way for by-pass air. If one set is too small , just take them out and run the inners.
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 Post subject: Re: by pass air
 Post Posted: Fri Sep 07, 2012 8:03 am 
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only issue I se with that is it's not filtered air,,,But I guess most of you guys don't run a filter anyway but I do..

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 Post subject: Re: by pass air
 Post Posted: Tue Sep 11, 2012 6:09 pm 
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The issue I see is that it's air not metered by the carb. The more I learn about carbs, the more I understand how things have been done and why. Personally, I'd rather drill the throttle blades or install them in the body of the carb.........just me though....

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 Post subject: Re: by pass air
 Post Posted: Tue Sep 11, 2012 6:57 pm 
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Coloradoracer wrote:
Personally, I'd rather drill the throttle blades or install them in the body of the carb.........just me though....


There's room for bleeds next to the air filter stud on a 4500 Dominator and I have seen a few with those but on a 4150 carb, space to put them in that area is somewhat of a problem.

Actually, if you think about it, putting them in that spacer directly under the idle fuel discharge port in the base "might" not be a bad thing as fuel going by that metered leak would likely get more atomization from the air flowing in through those bleeds. :-k

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 Post subject: Re: by pass air
 Post Posted: Tue Sep 11, 2012 8:38 pm 
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I did want to drill them right under the idle discharge port , but they are very hard to get to if you need to change sizes. You could drill intersecting passages , and make that work , that needs to be done on a mill ..........


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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 6:17 am 
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I guess if I had LOOKED before drilling I could have gotten much closer to the idle discharge. This is a Quick fuel , dont know if Holley idle discharge are placed the same?
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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 7:20 am 
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Looks to me that the right side of the throttle plate is closed completely.. You should be able to open that side some and have enough air there and not need by pass air at all...Or am I missing something #-o just saying...

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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 12:26 pm 
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Opps! Had it on backwards , carb is also a vacuum sec. the rear throttle place are not adjustable ....


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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 12:59 pm 
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Unless there different from a Holley there adjustable...

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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 1:12 pm 
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No allen screw or anything , just the tang around the base plate .... bending the tang work?

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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 2:17 pm 
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That's funny that there is no adjustment screw there on the bottom of that base plate..I don't see a problem with bending the that tang at all. It needs to be open as much at the front is I would think..That is what I would do and give it a try..

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running E85
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 Post subject: Re: by pass air
 Post Posted: Wed Sep 12, 2012 2:20 pm 
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WAIT A MINUTE? Does that carb even have secondary idle? Vac secondary with NO acc pump may not have any idle circuit back there either?


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