Hello, I have a 350 that has a quadrajet on it, and I was wondering what size jets and metering rods do you guys think I should be using. It has a measly 8.5 compression ratio because of the 72cc iron heads, it has a mild cam with 195*/202* duration @ 0.050", 0.390"/0.410" lift, restrictive 305 intake, very restrictive exhaust. In the future I plan to change the cam, intake, and exhaust. Will I have to change the settings again? Thanks,
John

 

The only way to determine the proper carb setup is to read spark plugs. You could also use an O2 meter or exhaust gas temperature guage.

Reguardless of how the engine is set up, you still want a 14.7:1 air/fuel ratio. It's always better to run on the richer side. Running fat will slow you down slightly but running lean will burn up parts.

O2 guage reading around 700mv is safe. I forgot what exhaust temp is good. Something like 800-900F.

Any changes to the engine will usually require rejetting the carb. Moving from LA to Denver also requires rejetting.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car
91 454SS daily driver
95 Homebuilt Harley

 

Thanks, Stephen! I think I remebember my uncle telling me that it is running a little lean (He's a mechanic and was performing a tune-up). Right now, I am running LG4 jets and rods and I ordered a kit that has jets and rods that are meant for the L69 (same just H.O.) Do you think that is a good idea if it's running lean already? Thanks in advance man.
John

P.S. is the 14.7:1 ratio for all cars or just carbed v8 cars? (just for future reference)

[This message has been edited by johns84bird (edited December 01, 2000).]

 

14.7:1 is for all engines running gasoline. fattening it up to 13:1 is fine but check the plugs for fouling. Alcohol is 6:1 and nitro-methane is 1:1.

Check out http://www.calgarydragracing.ab.ca/fuelmixtures.html