Valve Springs for 67 250 SL

[Atazman]

Gentlemen.........

I have my head in the machine shop getting a valve job done.  The head came apart with both an "inner" and an "outer" valve spring.  They tell me that all of the valve springs are collapsed and need replacement.  I have tried two different sources for parts (always reliable in the past), and they tell me that all they show is one valve spring for my engine. 

Can anyone tell me if the two spring design has been replaced with a single, stiffer valve spring?  Or are both the inner and outer springs still available.

Any advice is appreciated since the machine shop is waiting for my response.

[ja17]

All the mercedes engnes of the era had double springs.  These should not be a problem to find. Have you tried  Metric, the dealer or Classic Center?  The last time I checked they were fairly inexpensive. 

[Ziggy]

Recently I have been told by the MB dealer that the double springs were indeed replaced by a single spring, some 110 number.

[Atazman]

Thanks Joe and Ziggy........

I'll update you on what I have found thus far.  I will not say "who told me what" for fear of me misquoting them, but these contacts have provided me with some good information, and I'm moving ahead with my head work.

First, it seems that the "dual" springs have been replaced with a single spring.  For my engine (67 250 SL), the MB part number for the valve spring is 110-053-01-20.  Most MB shops are using this single spring I was told.  Another source of information is checking with his spring vendor to see if their spring can be used by itself.  I'm anxious to get that information, although I'm not sure of the part # he is researching.

2nd..... one very reputable shop is using the above spring but also the original "inner" spring along with it.  The "inner" spring (which I do not have a part # for) is not available, and their shop is using "good used inner springs" that pass their test criteria.  The use of the inner spring is desired more for providing valve stability than to gain the extra pressure for valve closure.

What I still do not know....and am puzzled by.....is whether the spring part # 110--053-01-20 is the same "outer"spring as originally provided in my car?  Or, if this particular spring is heavier and has a higher spring rate than the original "outer" spring, and thus provides the same closing pressure as the combination of the old "inner" and "outer" configuration?  Unless I hear different from someone real soon......my head will be assembled with new "outer" springs (part # 110-053-01-20), along with my old "inner" springs.  Hopefully I will not wipe out my camshaft because of too much valve spring pressure.

And another question for you guys........  I read here on the forum that about 0.035" clearance is needed between the valves and the top of the piston.  I'm curious if anyone has a magic, "go-no-go" clearance that I can measure with the head on the workbench.  Something like measuring the distance between the milled head surface and the top of the valve at the closest distance??  Is there such a measurement to make sure my valves will not hit the pistons before I get the head installed?

Sharing your knowledge is much appreciated.

[Rolf]

I recently bought springs for my '66, from the Classic Center which are double springs. I don't remember the price but they weren't costly at all.

[Atazman]

Hi Rolf.........

So far...so good.......!  My car is running great using the "new" outer springs along with my "old" inner springs.  Thanks for the input.