News:

The Org - Serving W116 Enthusiasts since 2004!

Main Menu

Can valve train components be swapped?

Started by raueda1, 22 August 2022, 02:28 PM

raueda1

For example, can I exchange used cams and keep the original-but-used rocker arms?  Or replace an old lifter for another used one and keep the original rocker arm instead of the rocker that was originally associated with the replacement lifter?  Or do these things wear into each other and become mated?  Assume here that the parts have no egregious defects such as scoring, wear grooves, etc. 

I ask because I have a collection of this stuff from a relatively low mileage engine.  During my rebuild I replaced the timing chain and used its cam sprockets which were far better than those in my engine.  My inner packrat tells me to keep this stuff.  But I'm getting rid of things (moving), so if it's useless there's no point.  Thanks and cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

daantjie

Dave I think the short answer is "no".  I have not personally torn down and rebuilt a motor, but all I have read and heard is that the rocker arms, cam and lifters all wear together, and thus you cannot, or rather should not mix/match new with old. 
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

You would want to keep a used set in the same order if you wanted to reuse everything. But you can use new rockers on an old cam. I've done so on my W108 as the rockers wear horribly on both ends and you have no choice but to replace them.  The hydraulic lifters have a small cap on top that is replaceable so the lifters are always good. The little caps are good also and worth more than you would think.
The bigger question is how many people are looking for a 6.9 cam. It does happen, but rarely.
Though much bigger and heavier, the entire head with cam and parts is probably more saleable. Only way to find out is list them on fleabay and wait a couple of years till someone bites.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

raueda1

Quote from: daantjie on 22 August 2022, 04:52 PMDave I think the short answer is "no".  I have not personally torn down and rebuilt a motor, but all I have read and heard is that the rocker arms, cam and lifters all wear together, and thus you cannot, or rather should not mix/match new with old. 
Thanks Daniel, that's what I figured. 
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

raueda1

Quote from: rumb on 22 August 2022, 06:06 PMYou would want to keep a used set in the same order if you wanted to reuse everything. But you can use new rockers on an old cam. I've done so on my W108 as the rockers wear horribly on both ends and you have no choice but to replace them.  The hydraulic lifters have a small cap on top that is replaceable so the lifters are always good. The little caps are good also and worth more than you would think.
The bigger question is how many people are looking for a 6.9 cam. It does happen, but rarely.
Though much bigger and heavier, the entire head with cam and parts is probably more saleable. Only way to find out is list them on fleabay and wait a couple of years till someone bites.
Is the cap you refer to on the W108?  I don't recall any such thing on the 6.9/M100 engine.  But there's a kind of cap on top of the valve spring retainer that comes in different thicknesses.  Naturally my stuff is NOT in the same order.  I'm painfully moving towards chucking it all.  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

rumb

 But there's a kind of cap on top of the valve spring retainer that comes in different thicknesses. 
[/quote]

Yup, that is correct and what I was referring to.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio