See 1976 Chevrolet pickup with Rochester quadrajet upgrade on SBC 350 V8. We removed the hood, mounted a camera looking down on the air horn, and took it for a spin, running wide open on an uphill grade. See how the secondary air valve responds to rpm drop at each upshift of the THM. Also included is a smoking burnout.
More Quadrajet tuning, some things! Part two in this Saga Sept 13, 2010
With the camera sitting on the oil filler cap a few more things to show how a metering rod system works on a carburetor. The car has a slight stumble and surge at a light throttle cruise at about 55 to 60 MPH. By swapping out the .050 metering rods to .048 units, the stumble and driveability concerns are now gone. Going richer would mean worse fuel mileage one may think? No! Now that the mixture is right, LESS throttle opening is needed now, which means higher vacuum, and this way the metering rods will block off the correct amount of fuel, and in the proper timing and percentages, so the car runs much smoother. As stated many times, patience and reading up on, and understanding how these intricate carburetors work will help out very much! Enjoy!
1986 Chevy C10 Custom 350 Engine
This is my 1986 Chevy C10 that I rebuilt. The tranny was a TH350 but we dropped that and stuck in a 700R4 overdrive. The engine was removed and we put in a 350 crate motor from JEGS, with our own customizations. All in all there is just over 300HP. Runs like a champ, just under 2000rpm at 70. Vs the old TH350 that had me reving at over 3500rpm. --- Also the performance radiator and waterpump keep this thing running amazingly cool. I did a 2 hour drive going 75mph the whole way, and I never once saw my gauges reading over 110 degrees.
-- Custom paint -- Once the engine compartmant was cleared it was sanded down completely and sprayed black with a clear coat finish. During installation we took a lot of the parts and painted them metallic blue. And added a lot of detailing with blue paint to bolts, screws, raised lettering, etc.
- Headman HTC headers
- Dual flowmaster Exhaust
- Be Cool aluminum 4 core radiator
- Flowcool water pump
- Edelbrock performance intake
- Edelbrock 600cfm 4 barrel carb
first tutorial ever take it easy on me. i didnt have the luxury of a vacuum gauge around so i did a general way of tuning a carb by ear. If u want a more perfect tune i suggest you use a vacuum gauge and or take it to a professional.
My brother-in-law and his father... His father started adjusting the carb some. Now I know why Edelbrock says his carbs are ready to go straight out of the box... Not enough adjustments and backfire if you do try to make adjustments with what you have to work with... NO FATHERS WERE HARMED IN THE MAKING OF THIS VIDEO...
How to debog your Quadrajet part 3
In the first two videos we looked at operational theory of the Quadrajet. In this episode we'll explore a couple mistakes the home mechanic often makes in an effort to improve the performance of this unit.
Quadrajet air leak fix and warped air horn repair tutorial.
How to identify a Quadrajet with a warped air horn without diss assembly or running it on a car. These tips would have saved me time and money which is why I made this video. I also discus how to repair a warped air horn and prevent your air horn from warping in the first place. If you have a whistling noise just off idle then you got some work to do. You will never get your engine tuned right, your cold start performing or decent fuel economy unless your four barrel carburetor is just right. Special thanks to Cliff Ruggles for his book Rochester Quadrajet carburetors and to my brother Adrian who spent hours on tuning and fitting.
See this video for description of the technique I used to straighten a warped air horn.
Fine Tuning S&S Carb.AVI
After 3 nights of screwin around with the carb, throttle cable, battery, points and condenser I got 'er to fire and idle for about a minute. That was the easy part. Now I gotta tune that carb. PATIENCE is not one of my virtues. LOL
Rochester Quadrajet, the results!
Two mishaps, the first shown here, the choke coil I got was wound backwards, it made the choke butterfly wind up TIGHTER as the engine warmed up. I swapped on the one from the old carburetor fast enough, the second mishap made me feel like a crud and what did I mess up later that evening. The car would not start leaving the Etobicoke -Queensway show. It was not getting gas. We got it running by priming the carburetor, and boy, was I ticked at myself. In the end it was not my fault it looks like. The new accelerator pump umbrella and rod was a very poor and frail design, the umbrella came detached and stayed at the bottom of the of the pump well, and was a distressed mess. The maker will get a note from me. The upshot? The old assembly went in, all is perfectly fine, the slight tip-in hesitation is gone now too. Stupid lack of pride it seems these days making parts for even simple things like an old carburetor.
How To Adjust The Accelerator Pump On Holley Carburetors
How-to adjust the accelerator pump on Holley carburetors to avoid stumbling and hesitation upon acceleration. Tips include: How to check for the clearance between the accelerator pump diaphragm arm & operating lever; how-to select the correct accelerator pump nozzle size, and accelerator pump cam selection and installation. Additional information can be found on Holley's website: http://forums.holley.com/entry.php?428-How-To-Cure-Carburetor-Stumble
Setting the timing and adjusting the carb
Set the timing by ear, and got the idle slowed down so I could do a little adjusting on the carb. I'll do more when it's cold, so I can set the choke and all. Love the way it's sounding..
Tuning Holley Carb- Engineering A Street Rod.mp4
Tuning the Holley 850 Carb that comes with the Chevy 502/502 Crate Engine was a fun but often frustrating task. Ultimately had to replace with an 850 Double Pumper. Even the Double Pumper needed modifications to meet our goal of 0 to 60 mph in under 3.5 seconds-which was accomplished. Details of what was done and why are outlined. Full details covered on our web site at www.netWelding.com/Holley_Carb.htm.