Weber Jetting Survey

[Snakebit]

After playing around with different jets, idle jet holders, and emulsion tube combinations, here is what I settled on. I tried 120 holders with a 65 idle jets and f7 emulsion tubes I leaned out the idle jets using a 1.20 holder and 60 idle jets. I switched to f5 emulsion tubes to richen up the transition changed idle holder to 1.10 with 60 jets, tried 155 mains with 210 airs. It still ran rich and the plugs were black

Engine 302 stroked to 331cu in.
CompCams 282S cam .236/.236 @.050
40mm chokes
f16 emulsion tubes
165 main jets
120 airs
1.10 idle jet holders
65 f10 idle jets.
Pump 50
Bypass 35
idle screws 3/4 out

The plugs are a dark tan, runs smooth. Lots of experimenting and spark plug changing, but well worth the effort.

Just put the car on a Mustang chasis dyno. AFR with the above set up was too lean in the high end AFR was 22. Went to 175 main jets and the AFR came down to 12.8 to 13.0. Idle circuit was 12.5. The distributor was recurved with 18* mechanical advance with a total of 20* advance at 2900 rpm.Initial advance is 18* for a total of 36*. You have to tune Webers on a dyno or hook up a wide band AFR meter.

New set up:
40 chokes
f16 emulsion tubes
175 main jets
120 airs
1.00 idle holders
65f10 idle jets
35 bypass
idle screws 3/4 out

Still had a slight hesitation around 2800 rpm and if I punched it at 2000 there was a bog until the fuel caught up with the air being dumped in.

I contacted Jim Inglese and gave him all my specs. He set me up with F11 tubes, idle jet holders, airs, and main jets and didn't rape me for the parts. He was almost dead on. I had to lean out the idle jet holder from a 90 to 100 and increase the main jet from 160 to a 165. I also changed the pump jets to 00. The hesitation is gone and so is the bog at 2000 rpm. Final set up is:

40 chokes
f11 emulsion tubes
1.65 main jets
200 airs
1.00 idle jet holders
65f10 main jets
00 pump jets
idle screws 3/4 out
fuel pressure at 2.5 psi
Timing 20* advance with 18* in the distributor for a total of 38* all in at 2900 rpm.

I want to get back on the dyno just to double check the air fuel ratio.