Thread: 1965 Chevelle 230 CID Tuning ?

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It has a Rochester Type BV single barrel carb.

I have just acquired this car and have been trying to get it to run correctly. I have set the timing, rebuilt the carb, stopped some leaks, etc.... It starts great now and does not flood the intake with mass amounts of fuel..... However, when rapping up the engine I get small and quick mini backfires at the highest RPM.... what is causing this? Also, explain the complete function of the choke vacuum unloader control.

Thanks, Bob

small quick mini backfires...... sounds like you might have a little valve float at higher rpms. Probably not what you want to hear, but try to keep from rapping it out too much. Those inline 6s weren't intended to operate at high rpms. Sorry I can't help you on the vacuum choke unloader thing.

The unloader pulls the choke off a bit when the engine starts.
Your high speed popping is probably valve float or sticking valves. Does it do it in gear, or just in neutral?

I have not checked for popping with the car in drive. I wiil do that tomorrow and report back with the result.

Thanks, Bob