Timing Issue

[dkennedy]

Before I tore the top half of my engine down, me and a buddy rolled the #1 piston around to the compression stroke and the distributor rotor was pointing toward the little "8" under the cap. I began cleaning the font of the motor this afternoon and found some timing marks that I didn't even know existed. The first picture is where my timing marks sit now... I made them red so you can see them. The second is a picture I jacked from somewhere on the WEB showing the correct orientation.

I'd love some opinions as to how I got this wrong, and advise on how to correct this.

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[Aloicious]

yup, those are the timing marks, you probably eyeballed TDC, which has an inherent bit of error in it, especially at TDC and BDC where there is not as much of an amount of physical piston movement per degree of crankshaft movement.

pull your distributor, re-orient to TDC with the timing marks (at #1 TDC, remember those timing marks show #1 TDC AND #6 TDC alternating), and re-install the distributor again. don't forget to scan to set the CMP offset.

 

[1997chevydriver]

http://www.gmt400.com/forum/showthread.php?t=6884

Here ya go!

Sent from somewhere in MN

 

[dkennedy]

Aloicious... I backed it back up the hill a bit and got the timing marks on the harmonic balancer and timing chain cover aligned. And the #1 piston topped out just as it should. The piston was up to the carbon ring around the top of the cylinder so I incorrectly assumed it was topped out. I'm just now realizing how many things I've forgotten since I hung up my wrenches so many years ago.

The distributor I took out had a crack in the back side where the ear for the screw hole that the cap screws into so the time I spent marking that was for nothing.

Thanks for the link Paul... I'll use this when I start reassembling the engine.