QuestionMy '71 (350/270 hp rodchecter Q-jet) corvette has been running oddly. I changed out the points to one of the HEI adapters and change the plug wires. I needed to reset the timing and when I checked it, it seen to be hard to see what to set first the carb idle or the disibutor. How do I know I'm setting the idle correct, if the timing is already off?
And the maker of the HEI adapter said that if I have trouble starting to leave the ignintion on for a sec. befow turning it over, do I now need a high voltage coil now? Because when I was driving it was running bad and it died and was hard to start right away. (seeing how i was sitting out in front of traffic!)
Also I had a rocker that was a little noisy and i tightened it a little and it seens fine, but what is the correct method for ideal rocker arm tightness, does it need to be in the #1 position to adjust all or 2,3,4, while adjusting etc. Just want to make sure that i did not mess it up by adjusting them. Thanks
AnswerI'm not familiar with the HEI adapter you have, but if it makes the car exactly like one which had HEI originaly, you don't need to do anything about the coil, as the new HEI distributor includes the coil inside it. If you do not have a standard GM made HEI system, I can't help you because I don't know what it consists of (that's why I say in my introduction that I don't get involved in a car that has been modified from original - I never know what has been done to the poor thing!).
As for which to set first, always set the ignition first - you can not get a good idle mixture setting or carb adjustment until after the ignition is set up correctly.
As for the noisy valve tappet, the right way to set these is with the engine idling slowly, take the valve cover off (I know, you'll get oil all over so spread towels around), and slowly tighten the rocker adjustment nut until the clicking just goes away, then slowly turn it one more 1/4 turn - this should be the end of the problem. You know, I assume, that setting them too tight will make the idle very lumpy.
When the engine is first assembled, they are all left very loose, so they all are clacking - then each one is tightened until it just quiets down, then adjust each one 1/4 of a turn at a time, with the engine idling. Do all 16, then come back to the first one and do the same thing again (now you have gone 1/2 turn from just quiet) - repeat this process very slowly (don't overdo it and make the engine stumble), until you have gone at least 1 whole turn from just quiet. I go 1 1/4 turns, and some go 1 1/2 turns, but anything in that range is OK. Since your car has already had this done to it (theoretically), I'm only telling you to go another 1/4 turn. If the clicking returns, your lifter is failing, or the rocker stud is pulling out of the head (not a rare problem on these!) - get ready to replace it!
Good Luck
Dick.
