617 turbo valve adjustment lobe position - PeachParts Mercedes-Benz Forum

Bob300DSD · #1 11-15-2007, 12:47 PM

I adjusted the valves last night on my 83 300D. I reviewed old ShopForum threads as well as threads all over the web.

I have two questions:

1.When I position the lobe at "1 o'clock" does the tip of the lobe point to the driver's side or passenger side of the car?

My MB service manual says: "positioning the camshaft so that the tip of the cam is vertical relative to the rocker arm." but the picture in the manual does not show the tip or lobe on on the camshaft in the diagram.

Diesel Giant says: "To your eye this will look like the lobe is in about the 1 o'clock position" but the tip of the camshaft lobe in his picture looks to me like it is pointing toward the passenger side of the vehicle, (the engine he is working on is a 617 non-turbo).

2.Can I lube the linkage with regular wheel bearing grease after I clean them?

Thanks for the help. I have two more valve adjustments to go.

Bob

Shawn D. · #2 11-15-2007, 12:53 PM

Quote:

Originally Posted by Bob300DSD

1.When I position the lobe at "1 o'clock" does the tip of the lobe point to the driver's side or passenger side of the car?

My MB service manual says: "positioning the camshaft so that the tip of the cam is vertical relative to the rocker arm." but the picture in the manual does not show the tip or lobe on on the camshaft in the diagram.

Diesel Giant says: "To your eye this will look like the lobe is in about the 1 o'clock position" but the tip of the camshaft lobe in his picture looks to me like it is pointing toward the passenger side of the vehicle, (the engine he is working on is a 617 non-turbo).

Just position the lobe so the lobe is pointed 180 degrees away from the rocker. That way, the cam will certainly be on the base circle.

guage · #3 11-15-2007, 12:59 PM

I stood on the drivers side using a bump starter and positioned the lobe as pictured here, which would be also pointing to the drivers side

I used trans fluid to lube the linkage

Bob300DSD · #4 11-15-2007, 01:32 PM

Quote:

Originally Posted by guage

I stood on the drivers side using a bump starter and positioned the lobe as pictured here, which would be also pointing to the drivers side

I used trans fluid to lube the linkage

Thanks for the feedback Guage, I interpreted things just as you.

Bob300DSD · #5 11-15-2007, 01:12 PM

Quote:

Originally Posted by Shawn D.

Just position the lobe so the lobe is pointed 180 degrees away from the rocker. That way, the cam will certainly be on the base circle.

When I look closely at the rocker it is not easy for me to discern the curve in the arm as displayed in the manual's diagram. Hence I am tempted to position the lobe straight up or positioned at 12 o'clock. When I turned the camshaft and checked clearance it seemed to me that the rockers had the most clearance at little past straight up at about 1 o'clock on the drivers' side. However the difference was so minimal it is hard for me to be sure there was actually any difference.

Bob

Brian Carlton · #6 11-15-2007, 01:31 PM

Quote:

Originally Posted by Bob300DSD

When I look closely at the rocker it is not easy for me to discern the curve in the arm as displayed in the manual's diagram. Hence I am tempted to position the lobe straight up or positioned at 12 o'clock. When I turned the camshaft and checked clearance it seemed to me that the rockers had the most clearance at little past straight up at about 1 o'clock on the drivers' side. However the difference was so minimal it is hard for me to be sure there was actually any difference.

Bob

We've had this discussion in the past and the opinions were varied. The question is whether the base circle of the camshaft is constant. If it is, then the slight difference between 12:00 and 1:00 is meaningless. Most folks conclude that it is not significant.

However, there were a couple of members who noted a difference in readings when the cam was moved from 12:00 to 1:00...........so, YMMV.

As Gauge mentioned, if you use the 1:00 position, it's toward the driver's side.

Bob300DSD · #7 11-15-2007, 01:38 PM

Quote:

Originally Posted by Brian Carlton

We've had this discussion in the past and the opinions were varied. The question is whether the base circle of the camshaft is constant. If it is, then the slight difference between 12:00 and 1:00 is meaningless. Most folks conclude that it is not significant.

However, there were a couple of members who noted a difference in readings when the cam was moved from 12:00 to 1:00...........so, YMMV.

As Gauge mentioned, if you use the 1:00 position, it's toward the driver's side.

Thanks Brian:

I think I have read every thread on ShopForum and the rest of the net and understood there was some varied opinions. I intentionally did this on my junker 300D before working on two cars with good engines. I was a little disappointed after I finished the job because the car still has really poor compression and wanted to make sure I did the procedure correctly. The valves on the car had no clearance prior to adjustment so I was hoping for the best.

Bob

Brian Carlton · #8 11-15-2007, 02:07 PM

Quote:

Originally Posted by Bob300DSD

Thanks Brian:

I think I have read every thread on ShopForum and the rest of the net and understood there was some varied opinions. I intentionally did this on my junker 300D before working on two cars with good engines. I was a little disappointed after I finished the job because the car still has really poor compression and wanted to make sure I did the procedure correctly. The valves on the car had no clearance prior to adjustment so I was hoping for the best.

Bob

Once the valves get down to zero clearance.........there's a chance that they don't fully close. If this happens, the seats are usually damaged from the heat.

..........there goes the compression.........

BIGRED · #9 11-15-2007, 03:16 PM

Had I known... while mine was apart.....I would have used a dial indicator to read the base of the lobe to see if there is a difference and if so...where the "sweet spot" is.

JHZR2 · #10 12-06-2009, 05:17 PM

Hello, just did an adjustment on mynew to me 82 300cd. I used the metal bar that stretches across all the cam towers as the reference point. That put me a bit beyond 1 o'clock but it looked right per the manual pictures.

Does anyone just align the lobe with the metal bar?

I havent done an adjustment since about 2003, and hope I didn't do it wrong. All were tight - I'll post the values later. I thought it was due to being due...

Thanks!

whunter · #11 12-06-2009, 07:05 PM

Quote:

Originally Posted by JHZR2

Hello, just did an adjustment on my-new to me 82 300cd. I used the metal bar that stretches across all the cam towers as the reference point. That put me a bit beyond 1 o'clock but it looked right per the manual pictures.

Does anyone just align the lobe with the metal bar?

I haven't done an adjustment since about 2003, and hope I didn't do it wrong. All were tight - I'll post the values later. I thought it was due to being due...

Thanks!

I use the cam shaft oiler tube as reference point..

Everything you need to do it correctly is here..

Valve adjustment OM617 FYI.
Valve adjustment OM615, 616, 617 FYI.

Have a great day.

warmblood58 · #12 12-07-2009, 05:28 PM

Quote:

Originally Posted by whunter

I use the cam shaft oiler tube as reference point..

Everything you need to do it correctly is here..

Valve adjustment OM617 FYI.
Valve adjustment OM615, 616, 617 FYI.

Have a great day.

I oriented off cam oiler tube as well -made eye balling a lot less complicated!

JHZR2 · #13 12-06-2009, 10:51 PM

Thanks.

So you line up (or point) the "tip" of the cam lobe with that tube?

My main concern is because before adjusting, I had the following readings:

#1E: .203mm
#1I: .152mm
#2I: .127mm
#2E: .229mm
#3E: .254mm
#3I: .173mm
#4I: .179mm
#4E: .229mm
#5E: .229mm
#5I: .102mm

So I had set each cam lobe to point exactly to the oiler tube on the cam towers. It matches up to the instruction pictures that way IMO, and also the cam is round for 120 degrees or so, Id guess there shouldn't be much variability, but those were pretty far off from the .10mm in and .35mm out per the sticker on the car. The interesting thing to me is, if they were done "right" last time, then while the exhausts all got tighter (expected), the intakes all got looser, how is that? The other option is that the last time the wrong specs were used.

Car idled and ran perfectly with those old settings. Going cross-country, I got mid 28 MPG, averaging 75 MPH, and spending time above or near 7500 ft.

One other thought/question. I did this job roughly at freezing. The car was definitely cold soaked, having not been used for over a week. Could this be "too cold", and cause me issues again later when ambient gets warmer?

Chain stretch at TDC: 4 degrees

leathermang · #14 12-06-2009, 11:01 PM

As clear as the FSM states where the cam lobe is supposed to point I can not believe there could be this much discussion about it.

If a person is having trouble getting and keeping the proper tolerance during valve setting the FSM suggests putting new cap and lock nuts on the valves as a first and cheap possible fix for the situation. They take a lot of pressure and pounding...so they can get worn on the threads and make it hard to hold the correct distance through the tightening process.

JHZR2 · #15 12-06-2009, 11:24 PM

As clear as the image is in the manual and in haynes type manuals, Im suprised that it is not mentioned that the oiling tube can be used as a reference point. It sure seems to line up right for me. But for those of us who have never really had to do this job before, and see it as a task with much to loose beause of a general lack of full understanding... it is important to have a sense of correctness and surety to the process.

Still, it helps to have a sounding board to ensure that my thought process and technique is absolutely correct, or not. Sure seem to see conflicting stuff, from vertical to one o'clock... Im referencing the graphic for angle and design of the system.

One thing that I did not do was crank all around and then recheck. Hope they are OK. The nuts all worked fine. Some needed a bit of oomph to loosen, but they worked, loosened and tightened just fine.