Valve adjustment, learning points

[jan lauwers]

Hello folks,

I am doing the valve adjustment on my 280 SL for the first time and I am learning the hard way. I want to share my findings; hopefully they can be of use.

1. The info that I found here is extremely useful. 66andBlue, George Davis and so many others, thank you!

2. Since 5 of the 12 bolts on mine were so tight, I have rounded a few, using the tool as in the attached pic (+bended arm). If I would so this again, I would first remove the rocker arms and break all the bolts loose with a socket, remove them, clean them, grease them and only then, use the special valve wrench to do the adjustment.

3. I made a tool for removing the rocker arms. This may be of use for those (like me) who cannot weld.  I screwed threaded rods in the holders of the camshaft cover (8mm). On those I put a strong wooden board with big roundels. Under the wood, I put a piece of copper tube that has the diameter of the spring cover, and I cut a space out for the cams. Tightening the bolts of the board compresses the spring (one by one). I have added some pics. It’s easy to make and easy to apply.

Thanks to all contributors, extremely useful forum this is!
Jan

[jan lauwers]

Hello Friends,

I have one more question on this topic please. I am removing the rocker arms with the tool that I have made. I have noticed that, even though the rockers are out, the springs still remain compressed to a degree. I did notice that because one of them
-for a reason that I don't understand-, came completely loose so that I could take out the inner and outer springs. The others somehow remain fixed and a bit compressed on their own. Does anybody know why that is? I suppose there is a risk that they jump? What is a safe way of loosening them, or should I just not do that?

Thank guys,

Jan

[Dave H]

Hi Jan
I notice you still have the cylinder head on the car... If the collets and springs have come off any valve you are now going to have to take the cylinder head off to get them back in.
Also by compressing the springs in that way it sounds like the piston under that valve was at TDC at the time , the valve could not go down and loosened the collets instead.
Without taking the head off , the only way you now have of compressing the springs to get the collets back in is to reverse what you did with the  piston underneath again at TDC to hold the valve in place and react off....but this could also bend the valve if you haven't done so already.
The valve lip only has to be bent a touch and it won't seal...poor compression etc.
I do not recommend this but if you go down this route do a compression test after to see if all is well with that cylinder .

[jan lauwers]

HI Dave,

This is BAD news, but thanks for telling me. I am learning fast!

Jan

[ja17]

Dave is correct on his analysis of the problem, but don't take the head off yet. Do not turn the engine. Sounds like you opened a valve onto a piston and unhooked the valve springs. The valve is sitting, unhooked, on top of the piston. If you turn the engine the valve will disappear into the cylinder never to be seen again. You need to find all the parts. Especially the two valve "keepers" .  Remove both rocker arms on that cylinder. Pull the valve stem up until the valve is closed. Pressurize the cylinder with an air hose and re-attach the springs and cap using the two, small, semi-circle, valve "keepers". You may want to find someone who is familiar with the process to help you. Be careful!  We can talk the process over lot more if you like,  it is  critical. Not much chance of bending a valve since the pistons are flat and the valves are exactly perpendicular so the valves touch" flat" on the piston tops.

[jan lauwers]

Dave and Joe,

Thanks again for your replies. Without your input, I think that I would not have understood so well what was going on. I have been traveling and only last night I could take a look again at the situation.
 I have taken the attached pic, which shows that the valve stam is still in place. I have all the pieces, so that's good news.
Here is what I plan to do now:
Turn the crank ace such that this cylinder stands in TDC, while I will hold up the valve stam, so that it can not fall inside the head.
At TDC, I suppose the valve will rest on the top of the piston and I will have max stam height above the cyl head.
Then I need to compress the 2 springs, without touching the stam until the top of the spring cover is below top of the stam.
Then I will carefully insert the 2 valve keepers with a pincet.
Slowly uncompress the springs again, hoping that the 2 halve valve keepers click in place and hold the springs and the cover.
Then put the rocker back in.
Does this make sense?

Thanks guys!

Jan   

[jan lauwers]

here is the pic

[Jack Jones]

Another way to hold the valve if compressed air is not available is to feed rope into the cylinder and then bring the piston up to hold the valve. this prevents any contact between the piston and valve and also eliminates having the engine spin over from the air pressure.

Jack  

[jan lauwers]

Thanks Jack... sounds very creative! I will try this weekend.

all the best

Jan

[ja17]

Yes, I have used the rope trick also.  Use a soft nylon rope.  You will find that compressing the valve springs is the most difficult part of the process if you do not have a special tool.

[jan lauwers]

Gentlemen,

It worked... and in fact it was a piece of cake. I launched a new model of my self made compressing tool , stronger than model one and with an extra window, to feed the 2 half valve keepers onto the stem. I greased them a bit and by slowly decompressing the spring, they clicked into place. The trick with the rope worked great. I am back on track now.

Thanks a lot for your help guys.

Jan

[Cees Klumper]

That's great, glad you came away without having to do a lot more work.

There are generic valve spring compressors available, but it looks like you made your own just fine.

[GGR]

Wow! Looks like you got lucky there. Good thing you did no turn the engine while that valve was sitting on top of the piston. Your spring compressor is quite creative!