Need More Power!
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Is that a re manufactured Quadrajet? If so, you need to open it up and see what the jet/rod combo is. What secondary rods and hanger does it have? Also, check the float level while you're in there. You need to make sure the throttles are opening all the way FROM THE PEDAL. You can back off on the spring tension on the secondary air valve about 1/8'th on one turn and see if that helps.
If the advance is to spech you need to set it at 12 to 16 degrees BTDC. You'll need to reset the idle speed after doing this. What does the centrifugal advance curve look like. You should have 36 degrees in by no more than 2800 RPM.
BigBlockk
Later.....
If the advance is to spech you need to set it at 12 to 16 degrees BTDC. You'll need to reset the idle speed after doing this. What does the centrifugal advance curve look like. You should have 36 degrees in by no more than 2800 RPM.
BigBlockk
Later.....
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you have rebuilt carbs before [successfully], you should have no problem. There are lots a info threads in forum archives to give you all the info you need. And there are good sources for any jets and/or rods you might need. Read the threads first, as there is a lot of prep information about checking out the carb and getting it ready for rebuild. Get a good quality rebuild kit and have at it. Then you can start fine tuning. If you don't want to DIY, you might contact LARS via the forum and see what kind of backlog he has at present. If he rebuilds it, it WILL be right! 
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Soon as it gets a little warmer I think I'll go to work on the carb and see what it will do. The two areas I plan to concentrate on are the secondaries (both the upper and lower throttle plates) and the accelerator pump.
I plan to "loosen up" the spring load on the upper plates so they will respond faster and adjust the rod to ensure the lower plates will open fully straight up.
With the pump I plan to move the rod connection to the lower hole to get a shot into the carb sooner.
Then after I see what it does I may look into a rebuild kit or give Lars a call.
cc
I plan to "loosen up" the spring load on the upper plates so they will respond faster and adjust the rod to ensure the lower plates will open fully straight up.
With the pump I plan to move the rod connection to the lower hole to get a shot into the carb sooner.
Then after I see what it does I may look into a rebuild kit or give Lars a call.
cc
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Same car here ... almost
I had the same issues with my 71 LS-5. I fought the bit*ch for a long time. I had the carb rebuilt by an expert ... hmm. Still no good
Then Lars recurved my dist and things got better, only a little.
I went with 3.55's. Then things got alot nicer. 
3.70's are too high for the street, IMHO. I added a hidden MSD, still using points. A saw a minor improvement. A chambered exhaust added sound, but not much go. ..... Finally .... a local carb expert got a hold of my Q-jet.
And $500 dollars later, the old girl runs like a CORVETTE SHOULD. My carb was pretty out of wack and now the car doesn't even run hot!
So if you want to learn from my experience:
- gears
- Good carb work ..... spend the $$ it makes a difference
- put on a nice exhaust and headers will wake it up.
After that it the standard stuff, intake, heads etc and the $$$ will really start to leave your pockets.
carbster
Then Lars recurved my dist and things got better, only a little.
I went with 3.55's. Then things got alot nicer. 3.70's are too high for the street, IMHO. I added a hidden MSD, still using points. A saw a minor improvement. A chambered exhaust added sound, but not much go. ..... Finally .... a local carb expert got a hold of my Q-jet. And $500 dollars later, the old girl runs like a CORVETTE SHOULD. My carb was pretty out of wack and now the car doesn't even run hot!
So if you want to learn from my experience:
- gears
- Good carb work ..... spend the $$ it makes a difference
- put on a nice exhaust and headers will wake it up.
After that it the standard stuff, intake, heads etc and the $$$ will really start to leave your pockets.
carbster
Thread Starter
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Thanks for the advice. My remanufactured carb has some funky numbers on it (29202DH 1759) where you'd expect to see 704xxxx.
Is there any way to be sure I have a Qjet that is up to the task before I put a bunch of money into it?
cc
Last edited by CCrane65; Jan 3, 2007 at 02:19 PM. Reason: sp
