I just recently set the timing in my 350 vortec headed motor and if I used #1 plug wire it would point to the 270 degree area, so I randomly picked out wires to clip the timing light to see if I could find one that would fire around the same time as the 20-30 degree range. I happened to be #5 cylinder and I set the timing for 22 degrees advanced and was able to get the idle speed down to the 1300 range out of gear. the cam is a solid lifter 242/246 duration camshaft. The motor has crisp throttle response and is not popping out the exhaust or the intake which leads me to believe that the timing is around where it needs to be, but why does #5 cylinder line up with the timing tape and not #1 cylinder. I installed the cam straight up with a double roller timing chain and the dots lined up just like every other cam i've installed. Any thoughts?

 

Does the tape itself line up with #1 TDC, if you turn the engine by hand to that point?

 

yes the tape itself was started on the slot on the balancer. although today i could check to see if the tape itself actually points to TDC, although that is how the rotor was lined up....off the #1 cylinder and that slot on the balancer for the intial cam break-in, and the motor fired up on the first turn of the key.

 

If you are using the stock balancer, then it is highly possible that the rubber elastomer surround has slipped out of position. If that i the case, then a new balancer would be a good idea. There is no point in having to re-locate TDC on the balancer every time you want to redo the timing. I personally have a Fluidampr damper that has the timing marks laser etched into the main body. That way, there is no slippage, and the timing marks are always where they need to be.

 

Did you put the tape on backwards?

Just s WAG.

 

Bring the motor to TDC and see how far off that tape is. I think you'll find that os a good bit off (as I think you've already concluded). If the elastomer has gone south, you know what to do.

To get by for now, mark the inner ring at TDC and time from that and by ear. If you don't think the elastomer slipped, mark both strait across so you can verify if there is/is not any shifting.

 

haha, thats crazy. i tmust have slipped since you last checked it!


Im lucky, my 1974 balancer has not slipped yet!

Its mark is still dead on 0* but im sure by now its not too effective in reducing harmonics...

 

well i do not believe the balancer has slipped it's ring since when i installed the cam at dot to dot and then installed the timing cover and balancer it was pointed directly on the slot at 0 degrees on the timing chain cover timing tab. Now where it gets tricky is the timing tape was put on correctly, but at #1 it points around 270ish and #5 is dead on and runs perfectly. the only thing i can possibly think of is the cam timing would be off somehow but it would have to be off a similar mark on the cam gear since there's no popping or sputtering and throttle response is very crisp with timing around 32 degrees advanced total, for the vortec heads i'm running. i'm not really sure where to look, i don't think the balancer is the problem, but i double checked the markings on the cam gear when installing it dot to dot. IIRC the cam "stud" that locates the cam gear was around the 2 o'clock position at dot to dot. any other thoughts? the motor was put together at the slot for TDC for cylinder #1 and the rotor pointing towards cylinder #1 and fired on the first try for cam break-in. I'm pretty much stumped here on what else it could be.

 

It's fairly easy to verify the timing mark on the damper (roughly). Remove the center balancer hub bolt. Note the position of the keyway broached in the balancer hub. Align that keyway directly toward the #1 cylinder (45° from vertical). The timing marks should indicate TDC at that point.

The groove in the balancer ring is usually cut about 7° retarded from the hub keyway:



If it has slipped as much as the timing light indicates, it should be obvious by this method. Another possibility is that the woodruff key in the crank snout was lost on installation.

 

vader i'll check that out on sunday. although when i intially installed the motor it was pointed essentially where your diagram shows, i'll see if it still does sunday. another weird thing is around 3500 rpm the timing light would stop lighting up for whatever reason, could the timing light be defective by chance?