350 tunnel ram w/new holley 450's still lean? [Archive] - Chevelle Tech

: 350 tunnel ram w/new holley 450's still lean?


Miggy
May 26th, 03, 4:02 AM
Hi guys.
Thanks for the help. Been doing all the things back from scratch, 1 at a time, and writing it in a log book. Car starts/ runs well now. Power vales are 9's. No die'n at stop signs. Miss is gone in the midrange when I started putting bigger jets in. You guys were right, tunnelram setup was running too lean I guess. Found float adjustments to be flakey... right one day, next day reset again. Re did timing to 36-38 at 2000. Re -adjusted valves to 1/8 turn from zero lash on hyd's. Still had miss and electric tach bounced all over. Pulled the MSD coil and ballast, for Accel hiperf one. R/r suspect plug and wires. Miss cleared (for now) Checked comp and all cyl within 5 pounds + - 150. Temp is 170 - 190 with 165 stat in.

So, after some short runs on the freeway, steady - no racing, just firm running, tail pipes and spark plugs still look lean. While at idle, runs great about 750 - 900. (reading I have been doing suggests that this setup will run poorly at idle when fuel is right for best power at speed)Your thoughts?
Thinking that I will keep on steppin up the jets till I hit too rich. What else should I look for on my journey to tune this setup through the idle/transition/secondary carb circuits?

Thanks Guys. graemlins/clonk.gif
Scott

a36chevy
May 29th, 03, 10:40 PM
Aren't tunnel rams just great!!! working with the jetting is the best place to start, but make sure that you have enough fuel pressure.

Miggy
May 30th, 03, 12:00 PM
Thanks for the support.. <g> I have a high output <chevy> type (looks like beefed up stock pump) and a clear fuel filter. I can see that the filter remains full through the run. I'll keep trying to upsize the jets till I see it flood.. lol, which used to happen alot. Had float and power valve issue in the beginning. It is fun to learn.

The more I know, the more I know how little I know!
Thanks,
Scott
1969 Chevelle (no parts match anything)lol SS396 HT body(used to have vinyl top I think) w / bnb 350 in it.