Tried starting the 455 for the first time since the rebuild. Thought I had everything timed correctly, but no start and random backfires through both exhaust and carb. With balancer line on 0 Deg. TDC on the timing tab, distributor rotor is 180 deg. away from #1 distributor post. I could have sworn I got the distributor dropped with rotor facing #1 at top of the TDC compression stroke, but maybe I was wrong. Is it common to make that mistake? Should I just try pulling the distributor and turning the shaft 180 and dropping back in, or is there another way of veriffying I do have it correctly set, and something else is wrong? Thanks!!

 

Are you perhaps losing sight of the fact that the crankshaft turns twice for every turn of the distributor?

Turn the crank through 360° and the rotor should point the other way.

The question is, when you do this, is the #1 piston on compression or overlap?
If it's not on compression, then, yes, you'll need to re-stab the distributor.

- Eric

 

I would say it is a common mistake because when you install the timing chain and have the dots at 6 and 12 o'clock The #1 piston is up but you will be 180 degrees out as far as ignition timing goes. It is easy to think you are good to go just to drop the dist in and put the rotor to #1. Actually # 7 is on TDC compression stroke at this point.

 

Not "should", but WILL point the other way. As Eric pointed out, there are two crank revs for ever one cam rev. That's why the cam gear is twice the diameter of the crank gear.

 

I am afraid that you have a stronger sense of certainty than I, Joe.

"Should," provided that the timing chain is installed, the distributor gear pin is in place, the crank key is in, etc.

- Eric