I took my M103 head to the machine shop without the cam and rockers installed. The machinist warned that when reinstalling the cam and rockers, it would be easy to pull the threads in the rocker stand bolt holes.

I left the intake manifold in place and need to slide the head into the manifold to start the center nut onto the stud. If I install the cam on the bench, some of the valves will be down and possibly get damaged when sliding the head sideways slightly. If I put on the head and then lay in the cam, and turn it a little at a time before timing it, I may cause valve/piston contact.

Can I simply place all the rocker assemblies on and tighten them all evenly and slowly?

Any suggestions regarding this?

Thanks,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Hi Larry,
I usually put the head on and then install the cam and rockers last. Don't worry about stripping the rocker support/cam bearing holes, they only torque to 21 Nm.Aluminum scares machinists that don't deal with it on a daily basis. I'm sure the guy has visions of impact gun torque applied to the bolts. Just put the cam in at TDC and tighten the rockers evenly. Works every time...
Regards,
Randy D.

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W.R.Durrance
ASE Master Tech
Mercedes Tech 21 Years
68 250SE
68 SAAB 96 Ice Racer
69 300SEL 6.3
70 300SEL 3.5
81 300TDT
W.R.Durrance Engineering

Larry. I removed the center stud from the head when removing same. Gives you a little more room to play. If you have the engine at TDC for #1 and lay in the cam, etc, at correct index mark, you will be fine re the valves and pistons greeting each other

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE

I understand how to set the head in place, and lay in the cam at a point that will not cause valve/piston contact. My concern was the machinists warning about pulling the threads. If this is a legitimate concern, I would need to lay the cam, turn it to a point where two lobes are down for the same rocker assembly, turn the cam so that two lobes are down for another assembly, etc. If I turn the cam witht the head in place, then I become concerned about valve/piston contact.

It sounds like I can mount and torque the head, turn the cam to the correct position relative to motor position (timed) and evenly tighten down the rocker arm assemblies without pulling rocker arm mounting hole threads. If, by being careful, I don't have to worry about pulling the threads, I think I'm good to go.

Thanks for the help, and I still welcome additional replies.



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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles