So here are some numbers from today. Keep in mind that I am working with 2, holley 600 carbs that have 6.5 power valves and size 62 main jets. The distributor has been recurved to have 12-14* of advance and all in around 2800. Base is at 22* @ idle So I’m at 35-36* total.
The issue I’m dealing with is a slight stumble when normal driving. There is no issue when launching car from idle in gear. Very quick with no hesitation that I noticed.
So I warmed the car up really well. Took it for a 3 mile drive which has flat, uphill and downhill. Fairly steep at start. Here are the vacuum numbers I had.
MPH. RPM. VACUUM
0- in park. 1200. 11
0- in gear. 1000. 7.5
25 in town flat. 1800. 14
35 coast slight down. 1700. 16
40 flat light throttle. 2500. 14-16
45 flat light throttle. 2800. 17
45 uphill moderate. 3000. 12
using light throttle there is a tip in hesitation. It’s very bad when engine is not totally warmed up. I should clarify there are no chokes. Both carbs have had them milled off. So where do I start? I plan on changing the secondary springs to the mid pressure spring before doing anything else to eliminate the possibility they let the secondaries come in too soon. Right now they have the lightest spring possible. Where to if that doesn’t cure it?
look forward to your thoughts.
Thanks Rod