September 26, 2018, 05:43 PM
C HodgeAlcohol carb question
With floats set in center of sight glass and I set the pro stage bring the car up to 25-2600 to bump in the car starts pulling fuel out of the boosters and flooding the car. If I lower floats to the bottom of the sight glass it won’t start pulling fuel through the boosters until 3200 rpm. I know I can put larger high speed bleeds in and fix this. My question is this. If it will run with the lower float level should I just lower and leave the air bleeds as they came with the carb or am I bandaiding the issue and just need to raise hi speed bleeds. Just trying not to mess up the calibration put in by carb company. I’m running an APD belt pump and there bypass with the fuel pressure at idle 3 lbs and 6.7 lbs at the finish line and the carb is a 4150 with down leg boosters.
September 26, 2018, 06:10 PM
27KeithTurn the rpm down to about 2000 rpm or less will also fix your issue.
September 26, 2018, 06:15 PM
C HodgeI tried that and it does fix the issue. But it takes longer than I like to bump in and I have to take larger bumps. 2500 is high enough to take small fast bumps to stage. Just seems like a low rpm to start pulling fuel
September 26, 2018, 06:41 PM
C HodgeCarb has 28 high speed bleeds
September 26, 2018, 08:20 PM
rustyquote:
posted September 26, 2018 06:41 PM Hide Post
Carb has 28 high speed bleeds
try .031 ,and then check for overall rich or lean.may have to go bigger on jet after air bleed change
September 27, 2018, 04:10 AM
Paul DilleyG,day,
I had the same issues,
My two cents is keep the tuneup the same initially.
Float height needs to be set with the bowls off and upside down, set the float height then reinstall them and don't touch them!
I found that depending on what rpm i wanted to stage at i backed the primary throttle adjustment back a bit and opened the rear a bit so that for a given rpm i had the primarys not as far open so the pulling fuel through the booster issue was ok, you just need to play a bit.
Leave the bleeds alone unless you have a data logger and can see a trend of it swinging either lean or rich through a gear and correct it then.
Depending on how much hp you have and what needle and seats you have you may need a mick hair more fuel pressure.
Cheers
September 27, 2018, 03:52 PM
C HodgeHadn't thought about that Paul, I'll try that tonight and see if it works
September 27, 2018, 05:57 PM
C HodgePaul closing the pri and opening the sec up some fixed it. 2500 and no fuel coming out of the boosters with floats set half way up the sight glass and car still jumps right up on the converter
September 27, 2018, 06:37 PM
Paul DilleyThat's good mate! just keep the dry float setting in the back of your mind.
Cheers
September 28, 2018, 10:50 AM
1st_Genquote:
Originally posted by Paul Dilley:
G,day,
I had the same issues,
My two cents is keep the tuneup the same initially.
Float height needs to be set with the bowls off and upside down, set the float height then reinstall them and don't touch them!
I found that depending on what rpm i wanted to stage at i backed the primary throttle adjustment back a bit and opened the rear a bit so that for a given rpm i had the primarys not as far open so the pulling fuel through the booster issue was ok, you just need to play a bit.
Leave the bleeds alone unless you have a data logger and can see a trend of it swinging either lean or rich through a gear and correct it then.
Depending on how much hp you have and what needle and seats you have you may need a mick hair more fuel pressure.
Cheers
Obviously excellent advise right here!