Timing marks - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mv7fd · 08-30-2014, 11:17 AM

The previous owner changed out the timing cover on the motor in my truck he said the teeth were at the top on the other cover and on this cover they are on the side does this affect the way you time it? He also put a paint pen mark on the balancer like 2 inches away from where the line is cut in.

MountainGoat1966 · 08-30-2014, 11:45 AM

I copied this from another site, hope this helps clear it up for you.:
The damper used from 1969 to about 1984 has the TDC line at the 2 o’clock position- or 10º before the keyway. You'll find that aftermarket dampers are the 10º type, as are the bolt-on tabs sold by the aftermarket, unless they're adjustable.
Warning Note: This includes the SBC 400, although the 400 damper is counterweighted because the engine is externally balanced, and the 1985-present 4.3L V6 with its respective 6.75" damper (raised outer lip) that has both a 2 o'clock and a 4 o'clock position (for some vans eg. G-series, Express, and Astro/Safari). Do not mix and match internal and external balanced dampers!
A third timing mark was used from (some) 1978 to about 1995, and nearly all 1984-1995 (exc for 1985-present 4.3L V6 and van applications). It is at the 12 o’clock position- or 40º before the keyway. This damper uses a timing cover that has the tab welded on at about the 12 o'clock position - the timing covers with this setup had either the 6.75" (305 and pre-1985 90 degree V6) or 8" (350/5.7 only). Professional Products lists the years for this type damper line as being 1984-1995 and is a 6-3/4” diameter damper.

geezer#99 · 08-30-2014, 01:05 PM

You can time it that way as long as the mark he put on the balancer is correct.
You can trust the mark or prove it's correct yourself. You need to find true tdc on #1.
You need to use a piston stop.
Here's a link about finding tdc and setting timing.
http://www.crankshaftcoalition.com/w...op_dead_center

08-30-2014, 11:45 AM	#2
MountainGoat1966 Registered User Join Date: Jan 2010 Location: northern arizona Posts: 259	Re: Timing marks I copied this from another site, hope this helps clear it up for you.: The damper used from 1969 to about 1984 has the TDC line at the 2 o’clock position- or 10º before the keyway. You'll find that aftermarket dampers are the 10º type, as are the bolt-on tabs sold by the aftermarket, unless they're adjustable. Warning Note: This includes the SBC 400, although the 400 damper is counterweighted because the engine is externally balanced, and the 1985-present 4.3L V6 with its respective 6.75" damper (raised outer lip) that has both a 2 o'clock and a 4 o'clock position (for some vans eg. G-series, Express, and Astro/Safari). Do not mix and match internal and external balanced dampers! A third timing mark was used from (some) 1978 to about 1995, and nearly all 1984-1995 (exc for 1985-present 4.3L V6 and van applications). It is at the 12 o’clock position- or 40º before the keyway. This damper uses a timing cover that has the tab welded on at about the 12 o'clock position - the timing covers with this setup had either the 6.75" (305 and pre-1985 90 degree V6) or 8" (350/5.7 only). Professional Products lists the years for this type damper line as being 1984-1995 and is a 6-3/4” diameter damper. __________________ "Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know."

08-30-2014, 01:05 PM	#3
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,734	Re: Timing marks You can time it that way as long as the mark he put on the balancer is correct. You can trust the mark or prove it's correct yourself. You need to find true tdc on #1. You need to use a piston stop. Here's a link about finding tdc and setting timing. http://www.crankshaftcoalition.com/w...op_dead_center

08-30-2014, 11:17 AM	#1
Mv7fd Registered User Join Date: Aug 2014 Location: Frederick md Posts: 178	Timing marks The previous owner changed out the timing cover on the motor in my truck he said the teeth were at the top on the other cover and on this cover they are on the side does this affect the way you time it? He also put a paint pen mark on the balancer like 2 inches away from where the line is cut in.



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