Timing adjustment - Page 2 - PeachParts Mercedes-Benz Forum

dataiv · #16 01-09-2006, 09:11 AM

Is there an IP timing how-to for 602 engines anywhere? I haven't been able to locate an (relatively) easy way to do it, but I'd like to check the timing on my 300D 2.5Turbo.

Hit Man X · #17 01-09-2006, 02:11 PM

Quote:

Originally Posted by dannym

Here are a couple of good timing chain threads.
The specs for timing chain are in all the online manuals.

http://www.peachparts.com/shopforum/showthread.php?t=96572

Q on timing chain stretch...

I have used the 2mm valve lift method and the cam mark method and see any difference in the measurement.

I just eyeballed the cam marks this weekend and the timing was off by about 3 deg. I installed a 4deg woodruff key last year so it's getting to the point where I need to replace the chain. Maybe I should start using synthetic oil.

Danny

Any FAQ on how to install that Key?

Brian Carlton · #18 01-09-2006, 02:31 PM

Quote:

Originally Posted by Hit Man X

Any FAQ on how to install that Key?

I have not done it personally, but, traditionally, the key simply sits in a milled slot in the camshaft. The old one is removed (sometimes it's a bit tight) and the new one is set in place. Again, depending on tolerances, you might need to force it into the slot with some vice grips.

Now, understand that this entire process is performed directly above the abyss. One false move and the key drops down into no-mans-land. Personally, I would not attempt the job until I fully covered the abyss with duct tape to prevent the inevitable.

dannym · #19 01-09-2006, 03:04 PM

Here's a good tutorial:

Sudden Chain Tensioner Spring Wear

Definitely stuff rags down the chain chase. The key comes out rather easy. There may be a washer behind the gear that you will have to remove.
You want to keep tension on the cam gear. I think I hung it up with a bungie cord.

This link will help you out:
http://skinnerbox.steaky.org/Service/W123/Index/617T/05Engine.htm
Select section 05-215
This link will also help you to select the proper key.

All in all it was a very easy job.

Danny

biopete · #20 01-09-2006, 05:43 PM

Quote:

Originally Posted by biopete

Anyway, Good news on my timing chain. Since I was at 23 BTDC on #1 cylander from the IP start of delivery check, I rotated around 23 Deg. to see the notches on the Camshaft washer and bearing housing line up perfect. !11 That is I read 0 on crankshaft damper and notches aligned on Camshaft Tower ( +- 1 Deg max.) Hang on for some pics. Does it matter that # cylander is up or should it always be the same reading on crankshaft damper when campshaft marks align as you said ? Be right back.

P.S. In chapter 2A of Haynes it talks about checking these marks but the manual never mention timing chain stretch check that i can find. It is in Camshaft R and R (removal and replacement). Not idiot proof though.

I lied. The centers of marks on Camshaft were not perfectly lined. And a little rotation in it moves the crankshaft a whole lot. The crankshaft if I counted right goes around 2 times per each camshaft revolution. Couple that with the much smaller diameter of the washer to the damper and well I did the math and went through the equations and all and rotating the camshaft 3 millimeters moves your crankshaft about 5 *.

Just kidding . I did not do any math. Just read the damper when the mark's centers were alligned and guessed I had them about 3 mm off from eachother.

Brian Carlton · #21 01-09-2006, 06:23 PM

Quote:

Originally Posted by biopete

I lied. The centers of marks on Camshaft were not perfectly lined. And a little rotation in it moves the crankshaft a whole lot. The crankshaft if I counted right goes around 2 times per each camshaft revolution. Couple that with the much smaller diameter of the washer to the damper and well I did the math and went through the equations and all and rotating the camshaft 3 millimeters moves your crankshaft about 5 *.

Just kidding . I did not do any math. Just read the damper when the mark's centers were alligned and guessed I had them about 3 mm off from eachother.

This is all exactly true. And, why I was originally doubtful of a chain with no stretch.

The marks have to be dead on. Even it they are off by one-half the width of the mark (about .5mm), there will be an error in determining the stretch. It's effectively impossible to do this by yourself unless you get extremely lucky. You are trying to move the crankshaft one degree at a time and simultanously observe the cam marks. Very difficult to do.

Hit Man X · #22 01-09-2006, 06:42 PM

Ah that sounds quite simple!

Gonna have to check my chain stretch and order the key here soon.

biopete · #23 01-09-2006, 06:56 PM

Quote:

Originally Posted by boneheaddoctor

Your cam reference point is not the mark but the valve at a certain lift...the specs of which I do not have handy.....the mark on the cam and head are assembly cues and not the precise point the cam is referenced at.

Hit Man X , We need to check this valve lift spec. That almost sounds easier than checking marks.

Brian Carlton · #24 01-09-2006, 07:16 PM

Quote:

Originally Posted by biopete

Hit Man X , We need to check this valve lift spec. That almost sounds easier than checking marks.

Here you go:

1) Remove the lash from the #1 intake valve so the clearance is zero with the camshaft on the base circle.

2) Setup a dial indicator on the valve spring retainer.

3) Rotate the engine until the valve opens by .079".

4) Read the degrees on the crankshaft damper.

5) The spec for a used chain for all 617 engines from 1980 forward is 11° ATDC. Anthing more than this is caused by the stretch in the chain.

Mitch H · #25 01-09-2006, 07:20 PM

Quote:

Originally Posted by Brian Carlton

You are trying to move the crankshaft one degree at a time and simultanously observe the cam marks. Very difficult to do.

I watch the cam marks while S-L-O-W-L-Y turning the power steering pump pulley. Usually takes me about three tries before I think I stopped it dead on without overshooting the mark a bit. Then I read the crank timing marks.