Help ls1 carb tuning
05-07-2013, 07:03 AM
#1
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Help ls1 carb tuning Hello everyone i was hoping someone can help me out. I have a carburated ls1 5.3 i cant seem to get the tune right. I am new to all of this, just so you know whats going on i have 72 primary jets with a 6.5 power valve and i have 80 secondarys with a 6.5 power valve. I pulled a plug and it was black and slightly wet. If i drive the car normal she runs good but once i mash the gas she stumbles/breaks up for a little then clears up.
05-07-2013, 08:39 AM
#4
You have a power valve in the secondary?
Also what carb, I'm guessing 650 double pumper (mechanical secondary)?
What accel pump, nozzles and accel pump cams front and back?
Single or dual plane intake?
Also what carb, I'm guessing 650 double pumper (mechanical secondary)?
What accel pump, nozzles and accel pump cams front and back?
Single or dual plane intake?
05-07-2013, 10:27 AM
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Yea there is a 6.5 power valve in the secondary
I belive it is a holly 750
Double pumper with michanical secondary
As for the accel pump idk
And the intake is a single plane its a jr victor
I belive it is a holly 750
Double pumper with michanical secondary
As for the accel pump idk
And the intake is a single plane its a jr victor
05-08-2013, 05:19 AM
#7
Are you sure it is an actual power valve and not a power valve plug? Secondary metering blocks have the power valve hole, but usually come with a solid screw in plug to block it off and disable it.
If it is then plug the secondary power valve. A power valve adds the equivalent of 6-7 jet sizes. No one runs one in the secondary, just doesn't make sense.
Here is a link from Holley on adjusting accel pumps
http://forums.holley.com/entry.php?4...uretor-Stumble
You want to do that after you get the jets right.
You have a challenging tune combo of a mechanical secondary carb that is slightly too large for the 5.3 and a single plane intake. It can all be made to work, your just going to need to do some learning and trial and error tuning. Keep good records of everything you change and how the car responds to them. If you are like me you will need to back up a time or three. The wideband will be worth it's weight in gold.
If it is then plug the secondary power valve. A power valve adds the equivalent of 6-7 jet sizes. No one runs one in the secondary, just doesn't make sense.
Here is a link from Holley on adjusting accel pumps
http://forums.holley.com/entry.php?4...uretor-Stumble
You want to do that after you get the jets right.
You have a challenging tune combo of a mechanical secondary carb that is slightly too large for the 5.3 and a single plane intake. It can all be made to work, your just going to need to do some learning and trial and error tuning. Keep good records of everything you change and how the car responds to them. If you are like me you will need to back up a time or three. The wideband will be worth it's weight in gold.
