I thought solid lifters stoped in '75 but your 280 may be something i need to learn about..and clockwise on a solid lifter engine will increase the space between rocker and cam...Jeff

 

Just to clarify - the M110 doesn't have lifters. It is a twin overhead cam monster with rockers bearing directly on the cam and valve stems.

I'm not sure how quiet you are trying to get the engine, but it will NEVER sound like a pushrod engine. The head is very thin (without the cambox) and all the valve gear is hardly damped for sound at all. The heads have very few coolant chambers as well - these usually help to quiet things down. The M110 is known as one of the more rattly engines around. This is normal and part of it's charm. It shouldn't be noticeably rattly on full noise, or rather you wont be able to hear any rattle over the glorious 6 cylinder howl...

The clearances you have used are bang on. I just did the clearances on mine the other day and it doesn't sound much different at all, but does feel a bit sharper.

The only tricky bit that you have to make sure you have got correct is the little spring clip monsters. Sometimes they can look like they are engaged properly, but are not. There is a ridge on the adjusting screw that the clip slides on to and clips quite positively on both sides. It is possible to get one side engaged and the other not.

Not sure about the knocking noise though. Kind of odd.

 

the advice on those clips is very good as i had one rocker that i kept adjusting and it was tight on one side and not the other so since this was my first time doing this i said this is not right and removed the clip and then adjusted the clearance wow i am glad i did...but with it being the rear one on the drivers side i was not happy reinstalling as like you said there is a groove so to speak... i had to get a wrench with wide span and push equal from top and push from the back to get it in right..\
Actually the next time i adjust i am going to remove those clips.. It is so much easier to get the right clearence with no additional pressure..You should be able to slide the feeler guage across not tight on one side..Jeff

 

Turn the bolts out = tighten the clearens more quite ........ and turn it in = wider the clearens more rattle .

 

Also if you change the clearances and only got a rattle after that then you might have loosened one of the tappets that needs replacing, for instance on my car it didnt have any taping noise before i adjusted them, and after one was making a loud taping noise and i had to replace it, so u might need to open up the top end again and check the torque on the interfering threaded tappets.

 

noisy engine

Just as a note, I had my 110 engine, 1977 280SL valves adjusted by a Mercedes mechanic in the Mercedes shop with 40 years experence and the engine is "noisy". He tells me that it is right on for adjustments. The car has fantastic power.

Jerry

 

true really and as i know about those engines M110 is that the newer ones from say 80s and in to w 126 280se those engines are more quiet dont know why but thats a whole difference the engines sounds much more tight and not that much rattle noice i know even that they did a mod on the cam house where cams bearings is sitting , they removed 2 bearings i think and thanks to that the oilpressure raised allmost 1 kg at idle . i allso read that thanks to that cind of mod those newer M110s lived longer tho.

 

I read something about them changing bearings at some point in time by reducing the number of bearings like the supercharched swede said. I think they went from 7 to 4 or something like that, but hell if I know. I'm not even sure where the things go.

Great topic, I don't think my car's engine is very loud, but after riding a loud motorcycle, my definition of loud might be different than yours. There is a certain amount of clattering but not noticable while driving. I had the mechanic do the valves adjustment a few years ago and nothing changed about the sound. I guess one of the lifters was stuck and needed replacing.

good luck folks!

 

Thank you all for your input. I will take the cover off and double check.

 

Just as a note, on the 1977 thru 1981 110 engine there are no lifters, hydraulic or solid, there are cam followers or sometimes referred to by USA folks as "rocker arms". These are all daul overhead cam engines so any tech, that tells you he needs to replace the lifters, take your car and run not walk away. The service manual shows the cold clearence to be intake 0.10mm or 0.004 inches and Exhaust 0.25mm or 0.01 inches. Cold means under 85 degrees F.