New 400 engine, stops running at idle with no warning, what is it?

Asked by Mar 17, 2011 at 01:10 AM about the 1977 Ford Thunderbird

Question type: Car Customization

Engine: 400 / 6.6L, 4.040 bore, EB performer dual plane intake, Holly 600cfm 4bbl with 1" open carb spacer, CompCam cam w/ 262 lift, with matching hydro lifters, push-rods, springs and roller-rockers. An HEI distributor @40,000v. PROformance plug wires, and Autolite spark plugs.
Starts good and idles good for about 3 or 4 mins. Then with no warning, it stops running, theres no sound like a howl or a squeak when it does. When it stops i can't re-start it until about an hour has passes. The battery is verified good, alternator is good, HEI is good or it wouldn't run, Ive adjusted the carb up and down and will do it on lean, rich or (just right). Someone with more under their belt than me (experience wise) throw me a bone... what is it im missing?

2 Answers


1 people found this helpful.

with a built head you may run in to problems with timing and/ or fuel problems. Check your lift on your cam could be to much for engine to handle believe it or not.

1 people found this helpful.

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