If it has mechanical secondaries you can set them to open whenever you want, from almost idle to at the very end of the throttle being all the way down. Vacuum secondary carbs don't work as good like the one you are showing.
I have a 1978 el camino with a quadrajet carb. today i was cleaning the carb with carb cleaner and i started it up afterward and now when i start it up it runs on high. i looked at the throttle and it was stuck so i pushed it back where it is supposed to be and i started it and it gets stuck AGAIN ! . what do i do ???? i need Help !!!
@mrjesspatrick the vacum is not the only thing that governs the air valve, there is a spring that is fully adjustable..I bet that if in this vid the guy rotated that spring adjustment out half a turn- 3/4 of a turn it would have opend up all the way
I have a 76 Chevy Truck with a sb350 running headers with a 4brrl rodchester q-jet carburetor, my problem with it is it runs like 1200rpm at idle but once it warms up it stays the same. But, when I put the truck in drive (it's automatic) it's slows right down and stalls. Every time! any advice to help me? You can watch the video of it on my channel in case you had to hear it running. Please help! thanks!
Manifold heat crossover valve actuator to the left of the carb (cylinder with vacuum line). Those replace the weighted thermostatic spring controlled valve for controlling exhaust flow through the crossover which heated the choke spring and the base of the carb.
The secondary flapper (which controls secondary fuel flow) does open all the way at high RPM, but closes slightly at lower RPM. The engine vacuum governs the flapper. If it were a built 350 I would suggest removing the vacuum pod and linkage, then the secondary flapper would open in accordance with the airflow into the engine. But be careful, if the engine does not need the extra fuel, it will run rich and possibly flood. Take the rod off and try it. If it works, great. If not, put it back
Its working exactly how it should....However the air flowing over the carb is disrupting the airflow into the airhorn in the video. Does your quadrajet have the 75% limiting tab on the air valves still? I know that even my mildly built 305 opens them all the way. When I cut the limiter tab off it picked up over two full tenths in the 1/8 mile.
I have the same 2gc set up with dual exhaust glasspacks, it has excellent low end throttle response but has no top end what so ever. I have a 4 bbl intake and Q-Jet needing rebuilding coming my way, can't wait to tinker with it!
i have a chevy with a 750cfm quadrajet and the secondaries never open. i bought a new cam close to stock. if i bought a larger cam around 216 to 220 degrees would the secondaries work.
i heard you can make the 600cfm carb into a 750 by making those plates open up wider, is there a way i can do that? im gonna be a building a high performance 350 and i was hoping i could keep prices down by modifying the stock carb. somebody please give me advice?
you should turn the spring tension for the sec air valve about one whole turn o ut and it should open all the way . since you have no lag when you punch it. It looks like they want to open but the spring tension is set stock. on the driver side of the carb on top back. youll see the scew
Many people say that other carbs are better, but the quadrajet is the best choice if you have a car intended for street use because of itś good fuel mileage in normal conditions, but with capability of great performance when itś needed.
If it has mechanical secondaries you can set them to open whenever you want, from almost idle to at the very end of the throttle being all the way down. Vacuum secondary carbs don't work as good like the one you are showing.
rodlamer 1 month ago
That was a awesome real world test video!
Starkster50 2 months ago
Listen to your granny!
1foxtrot70 3 months ago
I have a 1978 el camino with a quadrajet carb. today i was cleaning the carb with carb cleaner and i started it up afterward and now when i start it up it runs on high. i looked at the throttle and it was stuck so i pushed it back where it is supposed to be and i started it and it gets stuck AGAIN ! . what do i do ???? i need Help !!!
brandon1997bmx 4 months ago
Is that a screw type hose clamp on the AC compressor? That can't be good for holding in refrigerant.
monaco74 6 months ago
adjust the tension on the air valve and you can get quite a bit more midranged power ;)
RicerEater1978 10 months ago
oh man, I have wanted to do that sooooo badly on my car LOL, never took the time do do it thats awesum.
Mikej1592 10 months ago
Great video, thanks for taking the time to make and post this video, it really helped me understand the secondaries.
chairmnofthboard 11 months ago
ps never remove the air valve flaps
nattyicse 1 year ago
@mrjesspatrick the vacum is not the only thing that governs the air valve, there is a spring that is fully adjustable..I bet that if in this vid the guy rotated that spring adjustment out half a turn- 3/4 of a turn it would have opend up all the way
nattyicse 1 year ago
COOL VID!
MOPHONICA 1 year ago
I have a 76 Chevy Truck with a sb350 running headers with a 4brrl rodchester q-jet carburetor, my problem with it is it runs like 1200rpm at idle but once it warms up it stays the same. But, when I put the truck in drive (it's automatic) it's slows right down and stalls. Every time! any advice to help me? You can watch the video of it on my channel in case you had to hear it running. Please help! thanks!
76ChevyC10 1 year ago
Manifold heat crossover valve actuator to the left of the carb (cylinder with vacuum line). Those replace the weighted thermostatic spring controlled valve for controlling exhaust flow through the crossover which heated the choke spring and the base of the carb.
Nivicoman 1 year ago
The WOT is so much bad ass it almost brings tears hahaha
The1965Ghost 1 year ago
to me...the best carb. ever made!
silverpianolover 1 year ago
Great video.
thewhiteelephant 1 year ago
The secondary flapper (which controls secondary fuel flow) does open all the way at high RPM, but closes slightly at lower RPM. The engine vacuum governs the flapper. If it were a built 350 I would suggest removing the vacuum pod and linkage, then the secondary flapper would open in accordance with the airflow into the engine. But be careful, if the engine does not need the extra fuel, it will run rich and possibly flood. Take the rod off and try it. If it works, great. If not, put it back
MrJesspatrick 1 year ago
Its working exactly how it should....However the air flowing over the carb is disrupting the airflow into the airhorn in the video. Does your quadrajet have the 75% limiting tab on the air valves still? I know that even my mildly built 305 opens them all the way. When I cut the limiter tab off it picked up over two full tenths in the 1/8 mile.
Fast355 1 year ago
Loved it.. Great video...hang onto that truck...it will always treat you right.
sandman19681012 1 year ago
I have the same 2gc set up with dual exhaust glasspacks, it has excellent low end throttle response but has no top end what so ever. I have a 4 bbl intake and Q-Jet needing rebuilding coming my way, can't wait to tinker with it!
nandoGdog 1 year ago
gotta love granny.
kd5icr1967 1 year ago
i have a chevy with a 750cfm quadrajet and the secondaries never open. i bought a new cam close to stock. if i bought a larger cam around 216 to 220 degrees would the secondaries work.
m82a150 1 year ago
@m82a150 the linkage to the secondarys is probly off, alot of people do this to try and save on gas.
poppabear666 1 year ago
Sexy.
HeilSturm2718 1 year ago
the secondaries are fully open at 1:17
toranalover74 1 year ago
i heard you can make the 600cfm carb into a 750 by making those plates open up wider, is there a way i can do that? im gonna be a building a high performance 350 and i was hoping i could keep prices down by modifying the stock carb. somebody please give me advice?
adfasdfasdfluy 1 year ago
i learned how to rebuild a qjet through trial and error, Took me about 30 tries before i got it right.
Now when anyone calls em quadrajunk, i tell em sell it to me and they usually do for 20 bucks.
aknowneemus 1 year ago
you should turn the spring tension for the sec air valve about one whole turn o ut and it should open all the way . since you have no lag when you punch it. It looks like they want to open but the spring tension is set stock. on the driver side of the carb on top back. youll see the scew
nattyicse 1 year ago
Great video!
olds7980 1 year ago
i have been looking for a video of a down shot of a Q-Jet SWEET!!!
mkubiak67 1 year ago
Quadra yeah!
¡Very nice video!
Many people say that other carbs are better, but the quadrajet is the best choice if you have a car intended for street use because of itś good fuel mileage in normal conditions, but with capability of great performance when itś needed.
Excelent
ThunderChivo 2 years ago
Nice video.
chevfj40 2 years ago
google video 1901 Edelbrock
carburetormike 2 years ago
Awsome vid love the narration
xaviervahidy 2 years ago