1967 SB Idle Problem

[Duke W.]

Re: 1967 SB Idle Problem

Verify that your spark advance map is working to spec - specs are in your CSM, and check every vacuum device and all vacuum hoses for leaks. Then remove the carb and plug the heat slot under the carb base.

If the above checks/tests don't show any problems or solve the problem, run the tank to empty and pour in five gallons of race gas or 100LL avgas. Warm it up thoroughly and go through the idle speed/mixture adjustment procedure adjustment.

Avgas and race gas have lower vapor pressure and don't have any ethanol, so they are less prone to percolation.

If you can't get your engine to idle at 500 or not much above, I suspect you will fail PV because 500 is the spec and PV judges know that it should be smooth and stable.

Duke

[Dave K.]

Re: 1967 SB Idle Problem

Tom,

I, too was concerned about hot idle speed to meet the NCRS Operations Reference Guide requirements, on my 66 327/300hp base engine. As reported, I have problems with the engine smooth idling under 600 rpm. Book calls for 400-600 rpm.

I would check with Keith Biggers, 67 Team Leader, to confirm that he would hold you to the Standard Reference idle speeds for the PV. You may be surprised to hear that there is lee way here. Those reference idle speeds are based upon 60's technology and taken from the old Chevy Service Manuals.

Regards,
Dave Kitch
Master Judge- Pittsburgh Tri-State Chapter