did some air bleed tests,?

Posted By: Clanton

did some air bleed tests,? - 09/19/11 01:13 AM

but never made a pass at norwalk as i lost 1st gear pulling away from getting teched in on friday.

so i have a 3circuit dom and used a LM-1 trying to tune in my pit space as much as i could to get things going to make a pass.the idle A/F is 12.8/1 and i change3d the bleeds in the int and got the A/F down to 16/1 but it still stumbles but the sypmtom i am trying to cure is with the intercooler it leans out to almost 18/1 but stays running now at least.i put a .023 bleed in[smallest]stock bleed is 68 and with that the A/F was about 20/1.i have the pv's blocked.any ideas?

Posted By: PolyDart

Re: did some air bleed tests,? - 09/19/11 03:00 AM

Mine was stumbling when I tried to free rev the motor, or drive around the pits. Carb is a Pro-Systems 3 circuit Dominator with blocked powervalves. Patrick suggested running a 4.5 PV in the front and jetting down 10. Did that last night and the engine is running really clean now.

Posted By: Clanton

Re: did some air bleed tests,? - 09/19/11 12:50 PM

thanks.i am sure that is good info but i have a roots blown engine.i have 2 holley 1250cfm 80532-1 carbs.

Posted By: Clanton

Re: did some air bleed tests,? - 09/19/11 10:44 PM

i do understand that there is not much draw on the fuel with the engine not being under load or with it in gear and x amount of rpm.maybe one of you has warmed the engine and matched the A/F with load,no load info?

Posted By: 3404

Re: did some air bleed tests,? - 09/20/11 12:06 AM

Shouldn't idle A/F be adjusted with the idle screws and not the air bleeds? also why are you hitting such lean numbers with the adjustments of the air bleeds?

Posted By: Clanton

Re: did some air bleed tests,? - 09/20/11 12:37 AM

Quote:

Shouldn't idle A/F be adjusted with the idle screws and not the air bleeds? also why are you hitting such lean numbers with the adjustments of the air bleeds?

i did open the idle air bleed because i could only turn it out 1/4 turn[8 screws on 2 4bbls] and it was still rich so now the idle screws are out 3/4 and i need the extra fuel for the intercooler effect on it.now for the lean # with the air bleed in the intermediat circuit i am not sure why but the reduction on bleed size and the result effect on the A/F ratio shows it has an effect so i am confident the readings are good for under load.i have results power braking the convertor from last yr and it was in the uppper teens a/f.i have a video of it and will get it.

Posted By: Clanton

Re: did some air bleed tests,? - 09/20/11 12:44 AM

here is the video with the LC-1
http://www.youtube.com/watch?v=NIigVBZ8TME

Posted By: 3404

Re: did some air bleed tests,? - 09/20/11 03:29 AM

I would suggest a Holley carb performance book to get a good understanding how everything works and how they are all tied together.
There are many things that IMO have to be looked at and air bleeds may be the last thing to try.
Your video looks like trial under a load, so I think power valves and if the carbs are turned sideway maybe jet extensions on all 8 jets or raise the floats a bit?
A vacuum gage showing how much vacuum you have at a cruise speed will help you choose the proper power valve.
Idle screws richen the idle mixture when you open them and air bleeds will lean things out when you make them larger in size.
If you have the butterflys open just a bit to much the idle circuit completely drops out and you start pulling on the main circuit.

Posted By: Clanton

Re: did some air bleed tests,? - 09/20/11 12:51 PM

Thanks for the tips!it is allways good to review the carb function to help figure things out.

Posted By: RemCharger

Re: did some air bleed tests,? - 09/20/11 04:40 PM

Idle screws actually only meter the Volume of the emulsified idle mixture... The channel restriction changes the ratio...

Posted By: Clanton

Re: did some air bleed tests,? - 09/22/11 01:13 AM

Quote:

Idle screws actually only meter the Volume of the emulsified idle mixture... The channel restriction changes the ratio...

so who has changed the channel restrictor or emulsion bleed and what was the result effect %?

Posted By: Clanton

Re: did some air bleed tests,? - 09/22/11 11:57 PM

i talked to quick fuel and thay said i could only drill out my main feed starting by .010 bigger and the main discharge in the metering block by the same.

Attached picture 6837963-100_5890.JPG

Posted By: Clanton

Re: did some air bleed tests,? - 09/22/11 11:59 PM

i am not sure where the main discharge is in the plate.

Attached picture 6837967-100_5893.JPG

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 12:00 AM

or on this side.

Attached picture 6837969-100_5891.JPG

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 12:51 AM

i see in this pic the intermediat discharge is on the lower corners and is where i should drill.
anyone have any input?

Attached picture 6838035-3circuit.jpg

Posted By: RemCharger

Re: did some air bleed tests,? - 09/23/11 03:56 PM

Quote:

i am not sure where the main discharge is in the plate.

Needs bigger jets..

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 04:22 PM

Quote:

Quote:

i am not sure where the main discharge is in the plate.

Needs bigger jets..

i think i ment the intermediat discharge jet as shown above.my metering plate as above is not adjustable so maybe i will buy billet plates [34-77]

Posted By: 3404

Re: did some air bleed tests,? - 09/23/11 05:44 PM

Quote:

Quote:

Quote:

i am not sure where the main discharge is in the plate.

Needs bigger jets..

i think i ment the intermediat discharge jet as shown above.my metering plate as above is not adjustable so maybe i will buy billet plates [34-77]

Clanton, in my opinion you might want to have your carbs set up by someone who does that kind of work. With you being in Northern Ohio you have a few shops close by like APD in Sadusky and Dale Cubic (CFM) in Medina. Trying to run dual carbs is a bit of a different animal and like I said just my

drilling holes may be a no no or a quick way to end up with 2 junk carbs.
Air Bleeds and drilling holes is usually done after you have your carbs really close to being perfect and maybe something that is totally not necessary unless you are running pro-stock....

Posted By: RemCharger

Re: did some air bleed tests,? - 09/23/11 05:46 PM

Quote:

Quote:

Quote:

i am not sure where the main discharge is in the plate.

Needs bigger jets..

i think i ment the intermediat discharge jet as shown above.my metering plate as above is not adjustable so maybe i will buy billet plates [34-77]

Sorry, what i meant was,,, WHAT SIZE ARE THOSE JETS???

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 06:24 PM

Quote:

Quote:

Quote:

Quote:

i am not sure where the main discharge is in the plate.

Needs bigger jets..

i think i ment the intermediat discharge jet as shown above.my metering plate as above is not adjustable so maybe i will buy billet plates [34-77]

Clanton, in my opinion you might want to have your carbs set up by someone who does that kind of work. With you being in Northern Ohio you have a few shops close by like APD in Sadusky and Dale Cubic (CFM) in Medina. Trying to run dual carbs is a bit of a different animal and like I said just my drilling holes may be a no no or a quick way to end up with 2 junk carbs.
Air Bleeds and drilling holes is usually done after you have your carbs really close to being perfect and maybe something that is totally not necessary unless you are running pro-stock....

Thank you 3404 and i agree i dont want to endup with junk
carbs!

the jets in the plate are 110.

the high speed does ok at 12.8 a/f but needs more with those jets.

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 06:45 PM

i am wondering if i can drill my power valve blank in the pic above and put a jet in it or screw in adjuster to fattinup the intermediat.

or all and i can use [Edited by Moparts - Family Friendly Site - Keep it clean] bleeds in the hs then.

Posted By: MR_P_BODY

Re: did some air bleed tests,? - 09/23/11 06:53 PM

Thank you 3404 and i agree i dont want to endup with junk
carbs!

the jets in the plate are 110.

the high speed does ok at 12.8 a/f but needs more with those jets.

I cant believe you need 110 jets on a PAIR of carbs
unless your running E-85 and then it still doesnt sound
right

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 06:58 PM

i know mr p.some info on the carbs,it came with 100 jet and power valves so i blocked them and jettup.it is a 1250cfm carb.

like i said the high speed is close at 12.8 a/f and i have not touched those bleeds.just the intermediat is lean.

Posted By: MR_P_BODY

Re: did some air bleed tests,? - 09/23/11 07:01 PM

Quote:

i know mr p.some info on the car,it came with 100 jet and power valves so i blocked them and jettup.it is a 1250cfm carb.

I thought you had dual 4 barrels... so you only have
a single

Posted By: Clanton

Re: did some air bleed tests,? - 09/23/11 07:14 PM

i still have 2 1250's on it so i believe the lean condition because i an only using the pri side of the carbs reving it and load testing in gear.i have no down track data other than in the traps at 12.8 a/f.

Posted By: Clanton

Re: did some air bleed tests,? - 09/26/11 05:33 PM

i am realy thinking about drilling powervalve blanks/plugs as an inrichment meter.i can start with the pri side starting small.030 and go up.the plugs are cheap.[3$]

Posted By: Clanton

Re: did some air bleed tests,? - 09/27/11 07:10 PM

update:i talked to APD and i need to drill the hole next to the main jet in this pic and i will be able to come down in the airbleed eventualy so now the pv drill is no longer an option.