hi everyone, i'm new here, i'm in the process of rebuilding the engine of my 450 sel, but i got stuck lining up the cams to put the chain on, i asked before and they told me to put the no 1 cyl at tdc and line up the cam sprocket keys with the marks on the cam bearings, but i can't see any marks on the bearings (i see a few marks that look like casting marks), so if someone can help me out with the steps to line up the cams with the crank it would be great, i've been trying to do this for a few months now and no luck

cheers
aly

The marks ar on the front cam towers and the washer before the sprocket. This is located at about 1pm on your left side if I remember right.

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

do you mean the key opening in the washer, or are they any other marks at the sprocket, and for the timing tower what do the marks look like i can't see any marks on therejust a few casting marks that look like lines. sorry for the numerous questions but i really realy need your help on this one guys

The opening on the washer and on the cam tower. The tower has a very small line about 4-5mm long going from front to back. Should be about 1pm when looking in front.
m

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

oh ok i see the little mark. it lines up with the cam oiling rails on both heads

Aly,
I take it everything lined up with the piston and the timing on the crank was at 0 when the lines on the cam lined up.
m

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

well i saw the little marks on the cam bearings, the passenger side mark is on the front of bearing , the driver side is on the back (mainley cause the passenger side has a spacer between the sprocket and the bearing and the driver side does not).
and i also saw the notches on the washers, but the only thing worring me is when i line them up, the intake lobe on the number 1 cyl (passenger side head) is not pointing straight up like the book said it is pointing to 10 o clock( relative to the head angle), but the marks are lined up so i'm assuming the book screwed up...does everything i said sound reasonable or is there something really wrong here....i'm sorry for the whining but i've never worked on a benz before and i really want to get it right

Aly,
I can not rememmber as it has been a while since I worked on a 4.5. Perhaps Mike Tangas can be of help as I know he has one. The lobes of the cam shaft should both be pointing up and equi distance away from thier respective rockers if I remember correctly. Check and make sure you Timing on the crankshaft is lined up and is at 0 degrees when the cams are on the notch. I beleive the picture in the manual shows the picture as if the head where truely vertical which as it is a v8 it is obviously not so the lob should look vertical only when taking the degree of the V in the engine into account.

hope this helps.
m

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

When the crank is at zero the lob over the intake valve shouldn't be pointing staight up from surface of the head because the exhaust valve would then be opening, given the fixed relationship of the intake and the exhaust valve lobs on the cam. Remembering my 4.5 when the crank was at zero the lobs formed a V, intake at 10 o'clock and exhaust at 2 o'clock as I recall.

yes that's exactley what i have, intake at 10 and exhasut at 2, and for the #6 on the driver side head (the other piston at tdc when #1 is) they are reversed, so intake at 2 and exhasut at 10. this is confusing though cause for #1 at tdc in this case it is ready for ignition, and if the intake valve isn't fully closed (lobe straight up) then the combustion won't be very efficient, i.e gases will leak out of the chamber through the intake valve, right?
but any way thank you verry verry much for your help guys

Actually the lobe does not have to be pointing straight up for the valve to be fully closed cause half the cross section of the cam is a semi-circle I think.

ohh ok, i think you're right... ok just before i put it all together then, the #1 cylinder is located at passenger side cyl bank, right?
line #1 at tdc compression stroke, line up both cams with the little marks in the bearings until the #1 and # 6 lobes are pointing at 10 and 2 , then finally put the chain on... did i miss anything???

Sounds right. When you get the chain on crank it over a couple of times by hand to be sure nothing binds. Put a wrench on the crankshaft pulley nut only (27MM deep socket). It turns clockwise facing the engine.

hey bill i sent you a private message, take a look at it

The way I find top dead center on no#1 cylinders compression stroke is to screw compression gague into no# 1 spark plug hole then turn engine over with breaker bar and 27 mm socket when mark on balancer is coming up to zero compression gauge will start to rise a bit.......
William Rogers......