M103 cylinder head, valve specs
 

Anyone have the specs on the valves? Stem diameter? I have the 103 factory engine manual, and unbelievably, there is nothing beyond basic procedures. No valve data.

I have a 201 CD which I believe has the info, but for some reason the computer has decided it cant read it now.

ARRRGGG. Normally you can find this stuff rapidly on the web doing a search. But not that. Not today. Any help would be greatly appreciated.

Specifically, 8/88 300E 3.0. I knocked all the valves out and would like to mic them. The guides are sloppy and need to come out, I just want to know if I need a whole set of valves, too.

Mic the area at the top of the stem that has not run in the guide.

Lol, I was JUST thinking about that. Just a few minutes ago actually. Just after I swapped computers so I could read my W201 CD. Nothing there either. Almost $150 of Factory manuals covering the 103 engine, and nothing at all on valves. Nothing on the lower end either. Its odd, because my old W123 manuals go into that depth.

I could still use the specs though, like stem to guide clearance, installed height, spring specs, etc..

Stem to guide: .030-.065mm
Installed height: 1.5-2.0mm off coil bind

Long as you have the specs... I have 14.0465 mm guide bores. Std. size guides, correct?

Do you have stem height? I could use the stem height I have now as reference, but it would be nice to know the spec.

Sure is odd the book is silent. Anyone know if the data in in a haynes manual?

The guide bore size which you cite is in the middle of the range for the measured bore after knocking out a standard OD guide.

No specs for stem length, or a reference dimension for spring installed length.

Thank you. I guess I'll be ordering std guides then. I knocked em all out today. Need one valve and 12 guides. Seats all look good too.

I'll check with the dealer tomorrow, maybe the service guys can get me some more specs. ITMT, I will measure stem height what I have now, so if all else fails I can at least go back to that.

The replacement guide for the situation you describe is an "intermediate", which is larger than a standard, but smaller than a first repair stage. It does not require reaming.

Ooops, already ordered. Oh well. Its going into a long weekend. I'll get the guides and check the specs at the dealer. If they wont work, its only time. Its not like ive been in a big toot to get it going. A few days isnt going to kill it.

The guides fit real tight. In fact I was a bit concerned I would have trouble seating them. Got the valves ground, then putzed around the last week or so fixing other issues. Took it out for a run last night, she runs very strong.

Thanks to everyone for all the help.

Although I've not posted, I've followed this thread.. Glad to hear another old Benz is back on the road. I had an 87, when they run right they run better (I think) than any new Benz on the road... There isn't a plastic intake manifold to crack. :rolleyes::P:D

I cant say other than what ive heard. I had a salesman friend at Sears Imports back in the Twin Cities, he stopped selling them after the wiring fiasco. Said he just got tired of the factories hard line when everyone knew it was a major snafu. He had a lot of customers he had built up over many years, said it was hard to look them in the eye and sing the praises when he knew they were being given the shaft.

Several articles have argued the W124 and the M103 were the best car and engine ever built. I dont know about that exactly, but they are still nice solid cars, even by todays standards. Just have to maintain them.