M117 guide rails: Replacing aluminum-backed style w/plastic - Page 2 - PeachParts Mercedes-Benz Forum

300SDog · #16 11-03-2004, 01:46 AM

And the towers too, they should probably match their own camshafts for the sake of the bearings. Replaced camshafts and cam carrier on my 280/8 and was impeccable at keeping the parts matched, even the rocker arms were kept matching their lobes.

Tomguy · #17 11-03-2004, 10:54 AM

Well, no worries about that... I guess I should have said that I have the matching towers for those cams! The rocker arms on it now have only about 10k miles on them so I dont think it'd be a major issue not changing them. I should try to do my valve clearances today and see if that helps anything at all. I have a feeling I could put the 0.008 feeler in the intakes!

joshhol · #18 11-03-2004, 11:31 AM

So your valves are too loose? I guess that is good, usually they get tight and in the case of my 4.5, the adjusters are practically bottomed out in the head so new spacers would have to be put in at the spring retainer. Did you get a new set?

I'm not worried about it though as mine will likely be sold for parts.

psfred · #19 11-03-2004, 06:47 PM

That's called chain slap. The tensioner is also probably bad, it should hold oil overnight anyway, but if sitting longer it will be full of air, it extends with oil pressure.

If the chain is slapping that badly, it's time for a new one, start saving your pennies -- you will be amazed at the increase in performance at low speeds! Much better milage in town, too.

Peter

Tomguy · #20 11-03-2004, 06:50 PM

You must've had your heads rebuilt and valve seats lapped too low... mine are all well within adjustment range.

I did the clearances today - they were ALL WAY OFF except for 3 (two intakes and an exhaust). The rest, except for 1, were all WAY too loose! In my haste last time, I think I forgot to push the rocker arm down a bit , so it wasnt fully seated on top of the valve, adding space in there as well as the space between the rocker and the cam. There was an intake that was too tight and was in fact probably OPEN in the compression cycle when the engine got hot! Most took about 1/8th to 1/4 of a turn, but I did have an intake valve that took over 1/2 a turn! MUCH more power off the line, high end seems about the same, although the headers did NOT get red after a hard run up the mountain and the engine felt much cooler.

Edit: Also runs much quieter (not just at idle) and idle has smoothed out a lot... I still have flat engine mounts so I can feel every shake, and it was a lot less!