I have a 79 vette that I'm in the process of rebuilding. I tinkered with the timing the other day and I think I screwed up. First of all I cant use a timing light because the balancer has slipped or twisted on the rubber portion and my timing mark is nowhere near the indicators. I tried doing it by "ear or feel". Now I seem to have a knocking sound, not the valve pinging I remember getting with too much advance. More like a piston or two knocking. So any idea what I did, would this sound be indicative of too much advance or a retarded situation? I know it's hard from such a vague description. I noticed no other symptoms like backfiring from the carb or anything, although the car actually seems louder now if thats possible.
I'm sure about the balancer being off because I compared it to a correct one.
Also since the engine is probably not original I'm not even sure what the timing would be even if the balancer was OK.
That leads to my second question about spark plugs. I'm currently running ac delco plugs that a regular 79 calls for. What if this motor is definitely not original and comes from a different year chevy? The plugs would have to be different wouldnt they? How much of a problem would that cause? After doing the rebuilding the car always seems to have a slight miss, thats why I tinkered with the timing in the first place. The rebuild included a new crane 350/350 Lt1 cam, the car already had an edelbrock performer manifold and an MSD ignition system, 6A. I installed an edlebrock performer carb a few days ago. Thats the extent of the engine work, of course new plugs and wires.
ANy help as always apperciated, I'm gonna owe you guys a couple of cases of beer,
Thx, ESU in NY,

please remember 9-11 and support our troops overseas.

 

I'd start by trying to retime using your existing balancer mark. Since you mention that the engine is rebuilt and you're not sure that the engine is original, then MAYBE the balancer is OK. Start your engine, let it warm up, then disconnect and plug the vacuum advance line. Adjust your idle until it runs about 850RPM. Adjust your timing to 10*. You may have to readjust you idle back to 850RPM. If you still hear a knock or ping, let us know and we can help you deterimine TDC and remark your balancer good enough to retime.

 

Hi, the balancer is definitely not OK. I picked up a correct balancer for the car when I was re-assembling the motor front end. I compared the timing marks and they were way off. The mark on the new balancer corresponded to tdc while the old one was way off. Unfortunately the new balancer required a new keyway(?) and since I couldnt remove the old one I had to install the old balancer. However , before I did I matched up the new and old and scribed a new, correct mark on the old one. I used that one to time the car initially. That was a few months ago. When I checked the timing a few days ago the mark was way off the indicators again leading me to believe it was still slipping. I couldnt even get it close to the bottom of the indicator when I ran out adjustment on the distributor. Thats when I tried to do it by ear. Eventually I guess the proper thing to do is get the correct balancer on but till then I need help trying to figure this out.

Thx, ESU.

 

How does a ballancer slip if it's keyed. Can anyone explain this to someone who does not have a clue.

I am having a problem timing my engine after a swap also and have been searching the site for tips. There are lots of comments about ballancers slipping.

What gives?

 

The balancers are actually two pieces , an inner and outer seperated by a rubber gasket or cushion. The outer portion can slip around the inner portion because of the rubber. Simply put, probably a more technical explanation.
esu

 

Found the answer to my original question the hard way, way too much advance, bent wristpin, motor shot. Anybody got a 350 for sale cheap?