General Category > Quadrajet Carb Talk and Tips

I could use some help, please

(1/3) > >>

King Scooter:
I recently purchased a rebuild kit from Cliff. This is my 1st q-jet rebuild/mod. I am doing my best to follow his book, but have to admit, I'm a bit overwhelmed by all the new terms, circuits, recipes, configurations and such. But I'm having a good time.
My set up is...1972 full body Monte Carlo. 355 sbc, OEM 487x heads, 8.2:1 cr, cam is HFT .464, 214d @ .050, 110d LS with ICL @ 105. Cam is degreed and valve train geometry is correct. The cam specs listed are measured and what I'm actually getting. Stock cast iron intake, points converted to electronic module w/hotter coil, 1 5/8" headers w/dual 2.5" full exhaust, TH350 with Coan 2400-2600 stall, 3.31 posi. Power brake and A/C car. Not a daily driver, but I like to drive it aggressively and it's my long distance cruiser.
Carb is 7022210 QE 2381=1972 C-10 pick up, A/T, non California. Cliff supplied me with the sr rebuild kit as well as .125 fuel inlet seat .076 main jets, 43B primary MR and DA secondary metering rods.
Information gleaned since beginning the rebuild, and after getting the rebuild kit:
Idle tubes .039
Idle down channel .051
Lower air bleed .070
Upper air bleed .089
Accelerator pump discharge holes .074
Main air bleeds: Air horn & main body .042
Secondary POE well restriction .040
Secondary POE restriction .051
Secondary tube restrictions...one is .024 and the other is .038. Looks like 1 tube was replaced and maybe damaged during install, restricting flow to .024
Secondary MR hanger G
Idle bypass air .094
No holes in throttle plates
Can someone look at these specs and tell me what I need to do to maximize what I have? My numbers don't seem consistent with any of the recipes listed in the book. What parts can I use, what needs to be changed?
I'll try to answer any questions you may have.
Thanks
Scott

Ethan1:
 Scott,
 I would go with Recipe 1 in your case. It sounds like you have have a pretty mild cam/setup.

 .036" Idle Tubes
 .046" Idle Down Channel
 Your Lower IAB is good at .070".
 .069" Upper IAB
 .027" Accelerator Pump Discharge Holes
 .070" MAB's in Airhorn and Main Body
 .035" Secondary POE Well Resitriction
 .054" Secondary POE Restriction
 .036" Secondary Tube Restriction
 Secondary Hanger "K" or Higher ("G", I don't think will work)
 .050"-0.080" Idle Bypass Air

 What choke do you have also? Also, aren't those secondary metering rods a tad on the rich side?
 

King Scooter:
Ethan:
I'm running the stock heat stove, divorced choke. I haven't accurately timed the release yet, but it seems really fast, like less than 1 second based on sucking on it.
I can't say if the secondary metering rods are on the rich side as I have no idea. That is what was provided in the kit, so I trust it's what I need. But to be fair, Cliff didn't have this much info to work with. Is the large size maybe compensating for some other oversized orifice or circuit?
I did get a better measurement on the accelerator pump discharge openings of .022. I was measuring the opening at the air horn, not the actual discharge. Remember, I'm a rookie.
Now my questions:
-Is there a way to reduce the openings on my upper IAB? I'm at .089 and you suggest .069.
-Can you explain the secondary hangar lettering system? You say K or higher. Does that mean K, H or I or does it mean I, J or K. I'm not sure what direction means higher.
-One last thing, what is the proper way to measure the secondary air flap opening?
Thanks for your time & understanding. I'm sure I'll be ordering more parts in the near future, once I get this stuff sorted out.
Scott

Ethan1:

--- Quote from: King Scooter on March 23, 2017, 06:36:43 PM ---Ethan:
I'm running the stock heat stove, divorced choke. I haven't accurately timed the release yet, but it seems really fast, like less than 1 second based on sucking on it.
I can't say if the secondary metering rods are on the rich side as I have no idea. That is what was provided in the kit, so I trust it's what I need. But to be fair, Cliff didn't have this much info to work with. Is the large size maybe compensating for some other oversized orifice or circuit?
I did get a better measurement on the accelerator pump discharge openings of .022. I was measuring the opening at the air horn, not the actual discharge. Remember, I'm a rookie.
Now my questions:
-Is there a way to reduce the openings on my upper IAB? I'm at .089 and you suggest .069.
-Can you explain the secondary hangar lettering system? You say K or higher. Does that mean K, H or I or does it mean I, J or K. I'm not sure what direction means higher.
-One last thing, what is the proper way to measure the secondary air flap opening?
Thanks for your time & understanding. I'm sure I'll be ordering more parts in the near future, once I get this stuff sorted out.
Scott

--- End quote ---

 Scott,
 I believe you can stick a check ball in the hole and re-drill it. I am pretty sure that is what, Cliff, has done in the passed. Maybe even soldering up the holes?

 As for K and higher:
K      .565"
L    .570"
M    .575"
N    .580"
O    .585"
P    .590"
R    .595"
S    .600"
T    .605"
U    .610"
V    .615"

G is  .545"

The difference between those are the height at which they keep the rod in the jet. A hanger that is adjust higher will give you full rich faster as your secondaries open.

So, K or higher would be .565" or higher of lift.

The secondary air valve opening is a little tricky. I am not sure on it, Scott. I think I remember reading you have to take dial calipers and measure down from choke to when the secondary air valve is fully open. If I am wrong, I am wrong. Sorry. :(

Ethan1:
 Or it's from the back of the edge of the Qjet to the edge of the secondary air valve fully open. Try both methods. I think it's the latter of the two. :)

Navigation

[0] Message Index

[#] Next page