I thought I would share this one. I picked up my 83 HO a couple of weeks ago and I have been buttoning up things here and there as it had been stored for about 10 years. I was told that it leaked oil badly so I had a friend look it over before I picked it up and all that he could find was bad valve cover gaskets. I had him replace them. I did not believe that they could leak that much oil, but hey, what do I know. I got it ready and it drove home nicely. It obviously needed some tuning and all but I was satisfied.

A week later I was trying to time the engine in a friend's garage and the timing mark was impossibly off. When I left, I was surprised to find that I left a parting gift of a big puddle of oil on the ground and frantically stopped at the first gas station to top off and get it home asap. I ruled everything out and found that the damper must have spun. I believed that the oil leak was from the timing cover seal which probably helped it along. Thus the damper would have been slinging oil everywhere. This would also explain the amount of caked on oil covering most of the front of the engine.

So anyways, I tear it down and Find out that the vibration damper has not only spun, but slipped back towards the engine and cut a huge swath out of the timing cover, haha. I replaced the timing chain set, cover, seals, Water Pump, Damper, etc. and degreased the front of the engine. It runs great.

I have a question though. If the key is facing 12:00 on a L69 305, is the timing mark supposed to be around 11:00 or 1:00 on a stock damper?

For your viewing pleasure...

 

Timing mark should be around 12:00 @ #1 TDC.

The key is EXACTLY aligned with the #1 crank throw. Therefore it should be at EXACTLY 1:30 @ #1 TDC, since at #1 TDC, the crank throw is aligned EXACTLY with the cylinder. Not, 1:31; not, 1:29:50; 1:30. EXACTLY 1:30. EXACTLY 45° clockwise from 12:00.

L69 doesn't matter in this particular setting.

 

Having the outer ring of the balancer slip backwards and cut into the timing cover is nothing super-rare. The style of balancer they used had the rear edge of the balancer's outer ring only about 1/8" from the timing cover to start with from the factory. I had the stock balancer in my 78 Malibu's old original 305 do the same thing.

Agreed with Sofa, above about the position of the timing mark relative to the crank keyway. It should be a 6-3/4" diameter balancer with a 45* keyway offset ("12:00" timing tab TDC position- viewed straight down behind the water pump). Some engines of similar vintage (like TPIs) used a similar balancer but with a 13* keyway offset ("1:30" position TDC timing tab).

 

I suppose it's probably not. I knew they were close from the factory to the point that I did not notice this happening until I got a close look at it. I'm a bit puzzled by the timing marks being off though. I thought I did enough research before I installed it.

The timing is obviously set from the top down on this engine, and the damper that I bought had the mark to the left of the keyway which seemed correct. Yet when I disconnect the 4 wire connector by the firewall and hook up to plug #1 I see the timing mark a little to the left of the scale if I am facing the engine from the front. It's obviously running in time.

I have seen remarks about a damper with the timing marks at 12:30 instead of 12:00 at TDC. Does that exist? Because I would think that would line up correctly.