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Join Date: Feb 2004
Location: Sweden
Posts: 4,162
Garage
Replacing timing chains,

Hi guys
I posted in an erlier post that my timingchains where worn.
Now I have come to the point that I am replacing them with new masterlink chains.
I decieded to cut the old chain, link in the new, and turn the engine pulling the
chain along.
Before I started I checked the timing of the old chains. Both sides had 2.9 mm of lift and
acording to Waynes book it should be ~4.7mm for my engine (1977 2.7 cis).
Also I backed off every valve adjustment screw as much as possible to get some more clearence
turning the engine (Im I tinking right?) and removed the sparkplugs to make the engine easier to turn.
The right side went fine, the chain snagged a little but once it I got going it went round smoothly.
But on the left side.... I got the crank round ~360 degrees and then something restrikted the crank....
Its about 50 degrees after TDC for cyl #1. My fist thought was that the chain had sliped somehow
a piston hit a valve. But when I turned back to TDC for cyl #1 both cams was pointing straight (or very nearly)
up. Then the timing should be ok and the engine turnable, right?
I also went back to the stop and there I tried to screw in the valves tha where "on the lobes" and they could be
pushed in severel milimeters (I didnt feel any pistons).
Does anyone have any theory???


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911 Silver Targa -77, 3.2 -84 with custom ITBs and EFI.
911T Coupe -69, 3.6, G50, "RSR", track day.
924 -79 Rat Rod EFI/Turbo 375whp@1.85bar.
931 -79 under total restoration.
Old 03-15-2005, 03:38 AM
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