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9 Second 9" Tire Top Stocker Madness
Tom "Checkout My Suspension" Rix's 74 Apollo
Racing Junk Classifieds
9" Tire Lean Mean Through the "Factory Exhaust" Stock Appearing Machine
Steve Schlater and Dave Smith's "Hunting-Horsepower" 10 sec 72 GS
3850# "Jenny Craig" 9" Tire 100% NHRA Legal D/SA GS
Jody " The-Hardway" Plummer's Low 11 sec 1970 Stg1
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2 comments:
Jody,
You are the first person I have found to use the ruggles formula and I really like that.
I am working on a 1979 Buick 800cfm 350 Qjet 1079241. It has .073 jets and .048K tapered adjustable rods.
I need help deciding how to finish this project for my 67 GS 455 with ported St1 heads and c118 cam, 3000 S/p converter and 3.42
It runs mid 12's in the 1/4.
PUZZLES ....
1.The carb has only one .125 idle bypass hole! Do I drill the other side?
2.The horn gasket is .038 thick so somewhere between b and p I need to select a rod hanger that will work.
3. The orig. jets were .073 but John Osborne put .077 jets in my 72 Qjet. Is this late model carb needing to stay a little closer to the original? I have .075 and .077 jets. The .048k tapered rods are all I have for this late mocel carb.
4. I have two floats. one is black late model rear drop style and a brass late style replacement. Whitch one and what float level?? I have heard 9/32 for brass and .410" for black; and that all late models use LOW settings.
5. Some say set the rear throttle blades pointing roward the verticle bafffle to prevent turbulence and others say set them over center at slight angle toward the front for better fuel distribution, and others say 90 degrees only.
6. I will set air valve (flap) at 81 degrees and will use 3/4 to 1 turn. You agree?
Gary Bohannon garyb@newwavecomm.net
Gary,
Thanks for the comments. To be honest I have never worked on the later model Buick Q-Jets.
If I were working with your combination, I would pick-up a Buick Q-jet core on Ebay for a 71-76 Buick and start there with Ruggles information and recipe #1 on this site.
Cores are generally between $45 and $60. At least you will be starting with a carburetor designed for a 455 Buick.
Regarding your questions on setting up the carburetor and tuning, all I would be able to advise you on is the set-up for the 71-76 Q-Jet as I am not sure which components cross over between the early and the late model carburetors.
Rather than give you incorrect information, hopefully, someone with experience with the late model q-jet will read this and reply!
As far as dialing in your carburetor I would suggest heading to the track on a test and tune day or to a regular race where you can run time only runs.
Install a fresh set of plugs and make a pass. Using the plug reading info on this site determine where you are - rich or lean and make a change to one of the variables one at a time.
Make sure you record your incremental times and compare the incremental times after each run. I prefer to use weather corrected data so that you can take the weather variable out of the run data. This will allow you to directly compare data taken at different tracks.
This is a poor man's way to determine if the carburetor tuning changes have made a difference but more importantly at what point in the race they have made a difference.
Shy of running your engine on the dyno to dial in your carburetor it will take a bit of trial and error at the track to get things just right for your combination but that is the fun of it all!
Once you figure out how to make a late model q-jet work on the 455 I would be happy to post an article on this subject on your behalf!
Jody
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