Timing Chain help !
Thread Starter
Safety Car
Joined: Jun 2006
Posts: 3,611
Likes: 100
From: Palm Springs,Ca.
2020 C6 of the Year Finalist - Unmodified
Timing Chain help !
Havent done a timing chain in about 20 years, just want to make sure I remember correctly.
I have brought the engine to TDC by pulling #1 plug and tap ignition till compression stroke and distributor pointing at #1 spark plug wire and timing mark at 0. correct ?
I removed timing cover, the gear at the bottom has the line up dot right
at the top, but the cam gear dot is also at the top of that gear rather than the bottom, I thought they should be aligned dot to dot. Could the top gear be on wrong ? just want to make sure before I pull any gears off, any suggestions welcome. So far it was like riding a bike, it came apart very easily.
I have brought the engine to TDC by pulling #1 plug and tap ignition till compression stroke and distributor pointing at #1 spark plug wire and timing mark at 0. correct ?
I removed timing cover, the gear at the bottom has the line up dot right
at the top, but the cam gear dot is also at the top of that gear rather than the bottom, I thought they should be aligned dot to dot. Could the top gear be on wrong ? just want to make sure before I pull any gears off, any suggestions welcome. So far it was like riding a bike, it came apart very easily.
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,332
From: At my Bar drinking and wrenching in Lafayette Colorado
Top center on the compression stroke is with both dots straight up. If you put it together dot-to-dot like the "Chilton's" manual always shows, you will be on the exhaust stroke, and dropping your distributor in will result in the engine not firing. Correct installation is with both dots in the 12-o'clock position.
Lars
Lars
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
That is correct, you are at TDC for #1. Rotate the crank another 360* until the bots directly oppose each other. That is #6 TDC. Note the distributor rotor position so you can reinstall it correctly.
Last edited by big_G; Dec 30, 2006 at 01:15 PM.
Thread Starter
Safety Car
Joined: Jun 2006
Posts: 3,611
Likes: 100
From: Palm Springs,Ca.
2020 C6 of the Year Finalist - Unmodified
Top center on the compression stroke is with both dots straight up. If you put it together dot-to-dot like the "Chilton's" manual always shows, you will be on the exhaust stroke, and dropping your distributor in will result in the engine not firing. Correct installation is with both dots in the 12-o'clock position.
Lars
Lars
Thread Starter
Safety Car
Joined: Jun 2006
Posts: 3,611
Likes: 100
From: Palm Springs,Ca.
2020 C6 of the Year Finalist - Unmodified
and make sure it is the same place when done. Do I have to pull distbutor, I dont remember
Last edited by jdurhan; Dec 30, 2006 at 01:27 PM.
Tech Contributor
Joined: Aug 1999
Posts: 14,356
Likes: 6,332
From: At my Bar drinking and wrenching in Lafayette Colorado
You don't have to pull the distributor to change the chain and gear. If you pull it with both dots together, just put the new one on the same way. No problem. I always like to do it with both dots straight up so I know I'm at TDC #1 compression... just in case I screw something up I know where I started.
Thread Starter
Safety Car
Joined: Jun 2006
Posts: 3,611
Likes: 100
From: Palm Springs,Ca.
2020 C6 of the Year Finalist - Unmodified
Thanks guys for your help, as I said its been a long time since i pulled a motor apart but I thought I'd give it a try and so far all is good and feels good doing it myself. I love this forum.
Thanks again, have a great new year!
Thanks again, have a great new year!
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Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Top center on the compression stroke is with both dots straight up. If you put it together dot-to-dot like the "Chilton's" manual always shows, you will be on the exhaust stroke, and dropping your distributor in will result in the engine not firing. Correct installation is with both dots in the 12-o'clock position.
Lars
Lars
That's true no matter the cam? Roller, flats...ect...all the same? what about that alternate firing order cam?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
If you install the chain and gears with both dots at 12 o'clock, the engine is in position to fire the #1 cylinder. Dot to dot is firing #6.
The alternate 7/4 cams, rollers, hyd, solids, no difference.
The alternate 7/4 cams, rollers, hyd, solids, no difference.
Racer
Joined: Jul 2003
Posts: 455
Likes: 0
From: Buffalo New York
The aftermarket double roller that I got from Napa shows on the back of the packaging that it should be set up "dot (top sprocket at 6 o'clock) to dot (bottom sprocket at 12 o'clock). Comparing the original top sprocket (with nylon teeth, ugh) it matches up to the Napa one (ie dots 180 apart, top and bottom)...
Anyone else run into this?
Anyone else run into this?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
The aftermarket double roller that I got from Napa shows on the back of the packaging that it should be set up "dot (top sprocket at 6 o'clock) to dot (bottom sprocket at 12 o'clock). Comparing the original top sprocket (with nylon teeth, ugh) it matches up to the Napa one (ie dots 180 apart, top and bottom)...
Anyone else run into this?
Anyone else run into this?
I heard, when I was installing my roller chain and gears, to set the dots up like you just said. The cam gear at 6 o'clock and the crank gear at 12 o'clock. That's how I did it, and was going to change it at the behest of Lars and the guys...but I'm second guessing myself again.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
So it doesn't matter which way as long as the you turn it to #1 compression TDC to intall the distributer.
I personally match the dots and then turn to #1
Melting Slicks
Joined: Dec 2004
Posts: 2,101
Likes: 3
From: Cruising somewhere in St. Louis, Missouri
So I just installed a Edelbrock Double roller timing chain and it had me set the dot facing each other. So the top pulley marker was at 6 and the lower smaller pulley was set at 12 while cylinder #1 was at TDC. But this could still be wrong because it could not be on the power stroke?
Jim
Jim
Melting Slicks
Joined: Dec 2004
Posts: 2,101
Likes: 3
From: Cruising somewhere in St. Louis, Missouri