its a v6 3.4pr engine and i am installing a new timeing chain and need to know the correct positions of the marks. i have a chiltons and the pic it shows is a spot at 12o'clock 1TDC and 6o'clock 4TDC?? can you put it at either 12 or 6o'clock and its the same or what? i have dug a little on here and got two different stories on the cam gear position. i installed it with both gears at 12 straight up, and really want to make sure this is correct before installing anything else.... that i may have to tear back off thanks for your experteeeeese !

Ok, on the crank, you MUST have the dot facing straight up 12 O'clock.

On the cam it doesn't actually matter. Either 6 or 12 O'clock. Because once you've assembled it at 12 O'clock, you can rotate the crank exactly 1 turn, and all the sudden the mark is at 6 O'clock. So it's the exact same thing either way. The difference is that the #1 cylinder is between compression and combustion at 12 O'clock, which is where the distributor setting is adjusted from. The 6 O'clock position is where the #1 cylinder is between the exhaust and intake strokes, this is referred to where the distributor is 180 out.

I'ts been a while, there is a chance I have them backwards, but like I said, it doesn't really matter, at least until you set timing on the distributor.

quote Originally posted by Fierobsessed: Ok, on the crank, you MUST have the dot facing straight up 12 O'clock. On the cam it doesn't actually matter. Either 6 or 12 O'clock. Because once you've assembled it at 12 O'clock, you can rotate the crank exactly 1 turn, and all the sudden the mark is at 6 O'clock. So it's the exact same thing either way. The difference is that the #1 cylinder is between compression and combustion at 12 O'clock, which is where the distributor setting is adjusted from. The 6 O'clock position is where the #1 cylinder is between the exhaust and intake strokes, this is referred to where the distributor is 180 out. I'ts been a while, there is a chance I have them backwards, but like I said, it doesn't really matter, at least until you set timing on the distributor.

thank you for the response! it sounds like what i thought originaly. thanks again!

If you do make the mistake of having the cam at the 6 position and the crank at the 12 position, your new firing order would be 4,5,6,1,2,3

thanks! i have it at 12 &12 now so hopefully alls well as is.

quote Originally posted by Fierobsessed: Ok, on the crank, you MUST have the dot facing straight up 12 O'clock. On the cam it doesn't actually matter. Either 6 or 12 O'clock. Because once you've assembled it at 12 O'clock, you can rotate the crank exactly 1 turn, and all the sudden the mark is at 6 O'clock. So it's the exact same thing either way. The difference is that the #1 cylinder is between compression and combustion at 12 O'clock, which is where the distributor setting is adjusted from. The 6 O'clock position is where the #1 cylinder is between the exhaust and intake strokes, this is referred to where the distributor is 180 out. I'ts been a while, there is a chance I have them backwards, but like I said, it doesn't really matter, at least until you set timing on the distributor.

This is correct.

As mentioned above, you can have the cam gear at either 6 o'clock or 12 o'clock. Either way will work, as long as the crankshaft gear is at 12 o'clock. The difference is that when the cam gear is at 12 o'clock, you're at TDC #1. And when the cam gear is at 6 o'clock, you're at TDC #4. Set the distributer accordingly, and you're good to go.

I've always set the timing to 6 on the cam and 12 on the crank. V6 must be different.

quote Originally posted by Tuna Helper: I've always set the timing to 6 on the cam and 12 on the crank. V6 must be different.

Your method amounts to the same thing, because the cam rotates 1/2 the crank speed.

quote Originally posted by marc-alan: If you do make the mistake of having the cam at the 6 position and the crank at the 12 position, your new firing order would be 4,5,6,1,2,3

But to fix it turn the crank 360 degrees so your new firing order is 1 2 3 4 5 6

quote Originally posted by phonedawgz: But to fix it turn the crank 360 degrees so your new firing order is 1 2 3 4 5 6

LOL!!!

Since the cam rotates half the speed of the crank, you can install it either way. I always do 6 and 12 as that is the easiest to see whether the dots line up. if you do 12 and 12 it would still work, but your distributor rotor would be pointing 180 out from #1. Spin the crank 360 and the rotor would now point at #1 TDC. Firing order won't change.