Another Big Block Heat Question

[Joel T.]

I have another big block heat question/issue... 1965 L78

I have the carb set up so she will idle at around 950... Start her up, let the high idle run for a bit, tap the pedal and she will sit right at that 950 mark...

If I take her out and run her a bit she will run fine... smooth, nice power ,etc. However, when I come to a stop, the idle will become erratic and will drop down below 500. Park the car, let her cool down and the idle will be back to the 950 spot on...

I assume this has something to do with heat and the quality of gas here in NJ... I will get this on the small block to some extent but no where near as pronounced.

Aside from going out to the local airport and talking the guy into filling the car with aviation gas, will one of those commercially available octane boosters help?

Thanks!

Joel

[Jody B.]

Re: Another Big Block Heat Question

My 3124 came back from rebuild/restoration and ran perfect right out of the box. During the first test drive and after reaching operating temperature, mine did what you are describing. I came home and opened up both mixture screws about a 1/4 of a turn and its been perfect since then.

[Ronald L.]

Re: Another Big Block Heat Question

The octane boosters are usually alcohol and will cause you more problems as it could very well be the alcohol in your gas percolating. Just get the racing gas or av gas.

[Dennis S.]

Re: Another Big Block Heat Question

I'm having similar problems. Who knows for sure the percentage of ethanol being put in the gas. A gallon of C12 per tank full seems to help.

[Duke W.]

Re: Another Big Block Heat Question

The current EPA limit for ethanol is 10 percent by volume. Any more is a violation of EPA regulations.

Duke