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1983 380 SL
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Discussion Starter #201
Anybody have any suggestions on the best assembly lube to use on a 116.962 engine? I've been using Permatex Ultra-Slick Engine Assembly Lube but nothing feels like it's moving freely. The cams are especially stiff and don't turn easily in the towers even without any valves installed. It's not that they don't turn smoothly, they do, it's just that there is a lot more resistance to turning then I would have expected.
 

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1998 C280; 1987 560SL
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Anybody have any suggestions on the best assembly lube to use on a 116.962 engine? I've been using Permatex Ultra-Slick Engine Assembly Lube but nothing feels like it's moving freely. The cams are especially stiff and don't turn easily in the towers even without any valves installed. It's not that they don't turn smoothly, they do, it's just that there is a lot more resistance to turning then I would have expected.
Out of curiosity - how did check clearances with the cam bearings? I am hardly an expert at such, but the mechanics I used to work with on turbomachinery used plastigage to check clearances. Two things come to mind that might make the cams hard to turn - 1) clearance too tight or 2) cam tower misalignment. Not sure how you check that the cam towers are aligned?
 

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1983 380 SL
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Discussion Starter #203
Out of curiosity - how did check clearances with the cam bearings? I am hardly an expert at such, but the mechanics I used to work with on turbomachinery used plastigage to check clearances. Two things come to mind that might make the cams hard to turn - 1) clearance too tight or 2) cam tower misalignment. Not sure how you check that the cam towers are aligned?
The cam towers have location pins, no adjustment required or even possible. Also, there are no cam bearings. The Towers are aluminum which I assume were line bored with the cam towers in place on the head. I returned every cam tower to it's original location.
I'm guessing that the assembly lube is so thick (way thicker than oil) and the clearances are so tight that it's the assembly lube itself that is making the cam so hard to turn. It requires enough force to get it to turn that it's close to painful to be turning it by grabbing the cam sprocket. I wouldn't go so far as to say it's actually painful but you certainly are aware you've got a sprocket with teeth in your hand.

Lets put it this way... no matter how fast I try to turn the cam by the cam sprocket, it stops immediately as so as I let go. It takes considerable force to turn the cam by the cam sprocket. If that's normal when using assembly lube then fine... I've just never encountered it before. It may be that Permatex assembly lube is just too thick... more like grease than oil.
 

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1984 380 SL
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24 Posts
Hi,
just briefly looking at specs you have something like .025 clearance bet the camshaft and bearing, if it was to loose you would loose all your oil pressure when running as it would just flood through the towers,
here in the uk the engine build grease I use has the constistancy like a single/ light cream that you would put on your food!! If it was me I would remove the camshaft clean off all the grease then coat / smear all the journals/tower with engine oil and then just test it that way by hand. The grease is designed to stay there until the oil pump has had a fair chance to get the oil flowing around the system.
my thoughts anyway.. good luck
 

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1983 380 SL
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Discussion Starter #205
Hi,
just briefly looking at specs you have something like .025 clearance bet the camshaft and bearing, if it was to loose you would loose all your oil pressure when running as it would just flood through the towers,
here in the uk the engine build grease I use has the constistancy like a single/ light cream that you would put on your food!! If it was me I would remove the camshaft clean off all the grease then coat / smear all the journals/tower with engine oil and then just test it that way by hand. The grease is designed to stay there until the oil pump has had a fair chance to get the oil flowing around the system.
my thoughts anyway.. good luck
Excellent suggestion... I'll try it.
 

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1983 380 SL
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Discussion Starter #206
Removed the cams and cleaned off the assembly lube... put the cams back using motor oil instead of assembly lube and the difference is like night and day. The cams spin much freer now.
Thanks for the suggestion.
 

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1985 280SL
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253 Posts
As long as you're going to fire it ASAP, motor oil is fine. It will mostly drip off if you leave the engine sitting for awhile. That's why assembly lube is thick - it stays put.

I only use assembly lube when I don't know for sure when the engine will be fired. If it's going to be in the next few days after assembly, I use engine oil.
 

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1989 560SL
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98 Posts
I always used a product from GM called EOS (Engine Oil Supplement) which is also thick and gooey but certainly eliminates a dry start.
The other thing I did was leave the spark plugs out, disable the fuel pump and then crank the engine until I had oil pressure.


Sent from my iPad using Tapatalk
 

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1987 560 SL, 1990 300E 4Matic
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Removed the cams and cleaned off the assembly lube... put the cams back using motor oil instead of assembly lube and the difference is like night and day. The cams spin much freer now.
I'll bet you breathed a sigh of relief.
 

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1983 380 SL
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Discussion Starter #211
Figured I give you guys an update. I ordered and received the new main bearings and rod bearings but I haven't ordered the rings or gasket sets yet (4 kids worth of college loan payments can put a real dent in your mad money). I also have yet to find a good source for the drill template for the TimeSerts, nor have I ordered the TimeSerts yet.
.
Roncallo stopped by a few weeks (a month?) ago when he was visiting Long Island and we spent a few very pleasant hours talking shop over a couple of beers. I asked him a question (well, more than one) but on one of them he suggested I post it here because he didn't know the answer. So here it goes...

On the cams there is a large washer that goes on the front end of the cam just forward of the first cam tower. This washer has the timing mark on it (see red arrow pointing to the right) and the cam tower itself has the corrosponding timing mark (see the red arrow pointing up). The cam itself and the sprocket have locator notches for the Woodruff key and so does the large washer that has the timing mark. The problem is that large washer has 2 notches for the Woodruff key 180 degrees apart from each other. The question is... how do I know which notch to use? Anybody know?

MercCamTimingMark copy.jpg
 

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560SL '88 Suzuki GS1000E '78
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Hi Jyuma, this evening I will check my photo collection and maybe I can give you a feedback.
To do it like the scientists: Turn the crankshaft to 0° TDC cyl. 1. Taking the firing order, you can assign the cam position. For the first cylinder it’s very easy, because it’s perfect detectable. There both cams must be orientated in maximum rotary position away from the contact-point of the rocker. In this orientation the cam is in “TDC”-position for this side and cylinder. If not, turn the camshaft for 180°.

Now turn the crankshaft 90° (cw) so the 5. cylinder who is the next in TDC and firing-order reaches it's TDC, here you may have the same. The both cams (ex and in) need be located in maximum rotary position away. If not, turn the cam for about 180°.

Firing order M117:

Martin

Edit: 720/8=90 I edited the number reagarding "...Now turn the crankshaft 90° (cw) so the 5. cylinder...".
 

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1985 380 SL
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Figured I give you guys an update. I ordered and received the new main bearings and rod bearings but I haven't ordered the rings or gasket sets yet (4 kids worth of college loan payments can put a real dent in your mad money). I also have yet to find a good source for the drill template for the TimeSerts, nor have I ordered the TimeSerts yet.
.
Roncallo stopped by a few weeks (a month?) ago when he was visiting Long Island and we spent a few very pleasant hours talking shop over a couple of beers. I asked him a question (well, more than one) but on one of them he suggested I post it here because he didn't know the answer. So here it goes...

On the cams there is a large washer that goes on the front end of the cam just forward of the first cam tower. This washer has the timing mark on it (see red arrow pointing to the right) and the cam tower itself has the corrosponding timing mark (see the red arrow pointing up). The cam itself and the sprocket have locator notches for the Woodruff key and so does the large washer that has the timing mark. The problem is that large washer has 2 notches for the Woodruff key 180 degrees apart from each other. The question is... how do I know which notch to use? Anybody know?

View attachment 2620013
See below - is this what you are looking for?
2620085
 

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1983 380 SL
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2,495 Posts
Discussion Starter #214
Hi Jyuma, this evening I will check my photo collection and maybe I can give you a feedback.
To do it like the scientists: Turn the crankshaft to 0° TDC cyl. 1. Taking the firing order, you can assign the cam position. For the first cylinder it’s very easy, because it’s perfect detectable. There both cams must be orientated in maximum rotary position away from the contact-point of the rocker. In this orientation the cam is in “TDC”-position for this side and cylinder. If not, turn the camshaft for 180°.

Now turn the crankshaft 90° (cw) so the 5. cylinder who is the next in TDC and firing-order reaches it's TDC, here you may have the same. The both cams (ex and in) need be located in maximum rotary position away. If not, turn the cam for about 180°.

Firing order M117:

Martin

Edit: 720/8=90 I edited the number reagarding "...Now turn the crankshaft 90° (cw) so the 5. cylinder...".
Thank you for your response but the engine and heads are totally dismantled (empty block, no valves in heads) due to the fact that I'm doing a total rebuild of the engine. When I put it all back together I'll follow your guidelines. Thank you.
 

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1983 380 SL
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Discussion Starter #215
See below - is this what you are looking for?
View attachment 2620085
Now that makes it easy for assembly when the engine is just an empty block and the heads don't even have the cams installed. I knew there had to be a way to determine which way the washer went on but I never noticed or knew that the grove under the timing the mark is the one to use. Curious that they bothered to put two notches in the washer, there must be a reason.
Thanks you (y)
 

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450slc5.0cab 280sl5sp 280se4.5 500seAMG +250seStkW108 350sl4spdX3 500secEuro
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22,220 Posts
1-5-4-8-6-3-7-2. So Cyl 6 is 180 degrees off cyl 1. So I’d expect TDC, closed valves, bunny ears on cyl 1 to be 180 cam degrees off from cyl 6. Since you’ve only got two options, just make sure you aren’t “bunny ears” on cyl 6.
 

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1983 380 SL
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2,495 Posts
Discussion Starter #217
I just ordered the TimeSert Kit to repair the head bolt threads. I keep thinking that I'm not convinced I need the drill fixture to prepare the bolt holes to accept the TimeSerts. Please someone tell me again why the drill wouldn't follow the existing hole? I just can't shake the idea that the drill has no choice but to chase the existing hole.

Is it really a matter that it can't be done without a drill fixture or is it just harder to do without a drill fixture? I'm asking not telling. :unsure:
 

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1985 380 SL
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The Timesert instructions for the universal head bolt kits show the use of a drill fixture. The problem with doing these by hand is that you can't easily tell how straight (or round) the hole turned out. It is hard to make a really straight hole, even given the light material removal, when holding a drill by hand (particularly in aluminum). I suppose it has been done on these engines by hand with success however. At the very least, don't drill at an angle!
 

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1983 380 SL
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Discussion Starter #219
The Timesert instructions for the universal head bolt kits show the use of a drill fixture. The problem with doing these by hand is that you can't easily tell how straight (or round) the hole turned out. It is hard to make a really straight hole, even given the light material removal, when holding a drill by hand (particularly in aluminum). I suppose it has been done on these engines by hand with success however. At the very least, don't drill at an angle!
Thank you for your reply. I don't have a problem holding the drill motor perpendicular to the head, the problem would be holding the just shy of 2 degrees off perpendicular to the head for the 10 holes that secure both the head and the lower legs of the cam towers. Those are the ones that might get tricky but I still feel that the drill should follow the existing hole.

What I'm thinking of doing is after the TimeSert kit to gets here, I'll measure the diameter of the drill in the kit and compare it to the diameter of the existing threaded holes in the block. If all the drill needs to do is remove the existing thread without expanding the hole diameter beyond the thread thickness then I'll probably go ahead and drill it free hand. But if the drill size is large enough to make the bore hole a larger diameter, then I'll reconsider my options. I have access to a machine shop and could make my own drill jig if I could find the dimensions for the hole locations someplace.

I also considered making a drill jig out of plastic using my 3D printer but again I would need the exactly dimensions of the hole locations. I could make the plastic drill jig thick enough to hold drill bushings of the proper size and then have the best of both worlds. I wouldn't even care if it was single use but I don't see why it would have to be. Obviously it wouldn't hold up as well as steel but how many times is it going to be used?

I know, I know... seems like a lot to go through just to avoid the $100 expense of renting a drill jig for a week, but I'm not known for taking the easy route. (Cough... gas tank).

Hopefully I'll come to my senses and rent the damn drill jig.
 

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1986 560SL with M120 V12 Engine, 1988 560SL Stock
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Thank you for your reply. I don't have a problem holding the drill motor perpendicular to the head, the problem would be holding the just shy of 2 degrees off perpendicular to the head for the 10 holes that secure both the head and the lower legs of the cam towers. Those are the ones that might get tricky but I still feel that the drill should follow the existing hole.

What I'm thinking of doing is after the TimeSert kit to gets here, I'll measure the diameter of the drill in the kit and compare it to the diameter of the existing threaded holes in the block. If all the drill needs to do is remove the existing thread without expanding the hole diameter beyond the thread thickness then I'll probably go ahead and drill it free hand. But if the drill size is large enough to make the bore hole a larger diameter, then I'll reconsider my options. I have access to a machine shop and could make my own drill jig if I could find the dimensions for the hole locations someplace.

I also considered making a drill jig out of plastic using my 3D printer but again I would need the exactly dimensions of the hole locations. I could make the plastic drill jig thick enough to hold drill bushings of the proper size and then have the best of both worlds. I wouldn't even care if it was single use but I don't see why it would have to be. Obviously it wouldn't hold up as well as steel but how many times is it going to be used?

I know, I know... seems like a lot to go through just to avoid the $100 expense of renting a drill jig for a week, but I'm not known for taking the easy route. (Cough... gas tank).

Hopefully I'll come to my senses and rent the damn drill jig.
$100 is a no brainier. I couldn't find a rental when I did mine.
 
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