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The "Goldilocks" restoration thread

Started by ptashek, 28 March 2014, 07:56 AM

marku

Zinc? Very interesting I didn't know will certainly consider it.
450SE silver green/bamboo velour/green vinyl roof

ptashek

Taken from my 1979 manual.


Both 20W and 15W are considered optimal. I'll try a 20W-50 in the next service, maybe it'll prove a better choice indeed. I think Castrol have a 20W-50 in their "classic" range, which is formulated to API SF spec.

I'm assuming that by "zinc" you're referring to ZDDP, which adds both phosphorus and zinc to the formulation.
API SE/SF oils (i.e. 1972 to 1988 range) have a ~1400ppm phosphorus limit, API SL oils (like the one I use) - 1000ppm. Newer specs quote a minimum of 600ppm, and a limit of 800ppm. There are no recommendations for zinc content (http://www.api.org/~/media/files/certification/engine-oil-diesel/publications/150917thaddendum1-032515.pdf?la=en), so its directly related to whatever percentage of ZDDP it constitutes. Phosphorus content limits only apply to 20 and 30 grade oils, not 40 or higher.

There is research (https://link.springer.com/article/10.1007/s11249-016-0706-7) showing that even at a concentration of just 800ppm (phosphorus), ZDDP is very effective. Where the effects of ZDDP, or lack thereof, should be most visible is the cam lobes which experience high shear stress, not valve guides.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

UTn_boy

Lucas, two things......1) The book isn't always right, and 2) The research done regarding the use of ZDDP wasn't performed on an old V-8 Mercedes engine. 

When you say Phosphorus limits, are you saying lower viscosity oils have limits, and if so, are the maxima or minima? 

While you're correct on the effects of ZDDP, or lack thereof, should be most visible is the cam lobes which experience high shear stress, I'm pretty certain the guides and valve stems are just as prone to wear without ZDDP.  The stems and guides are the second highest items in the top end in which sheer stress is prevalent. 
1966 250se coupe`,black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3,papyrus white/dark red leather
1975 450se, pine green metallic/green leather
1973 300sel 4.5,silver blue metallic/blue leather
1979 450sel 516 red/bamboo

ptashek

Quote from: UTn_boy on 28 April 2017, 02:54 PM
1) The book isn't always right

It was written in an era where engineers, not marketers, wrote these. I trust it to be right :)

Quote2) The research done regarding the use of ZDDP wasn't performed on an old V-8 Mercedes engine.

Irrelevant, since such research is mostly done using domain specific testing equipment. Otherwise the results wouldn't be comparable in a consistent way.
There's another interesting paper covering ZDDP and formulations with it, without it, and in combination with other additives: https://goo.gl/ROKHGS

Let's put it this way, I'll trust the engineers behind modern oil formulations, before I'll trust countless forums and people crying "wolf" because their oil is not what they were buying the last 40 years. Even more so, as I haven't yet seen any trustworthy evidence that using modern oils in classic engines causes their untimely demise.

QuoteWhen you say Phosphorus limits, are you saying lower viscosity oils have limits, and if so, are the maxima or minima? 

According to the API spec requirements, only the thinner grades do have limits, and it's always the upper bound.
Except for API SM and newer, which set both the upper (800ppm) and lower bounds (600ppm).
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

UTn_boy

You shouldn't put that must trust in what you trust.  I've seen far too many camshafts and heads ruined to believe otherwise.  However, have it your way.  I won't comment about it ever again.  I was only trying to help. 
1966 250se coupe`,black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3,papyrus white/dark red leather
1975 450se, pine green metallic/green leather
1973 300sel 4.5,silver blue metallic/blue leather
1979 450sel 516 red/bamboo

ptashek

Current API spec tests, for anti-wear properties of an oil, target 350lb of force at the tappet. There is one research paper from 1958 which shows, through controlled lab tests, that at a concentration of just 800ppm, ZDDP provides more than adequate protection even at 600lb (which was the limit of the lab equipment at the time). Basically, buy any high quality API SL rated oil, and you're good. There is zero research to support the contrary.

There is also enough research around showing that at concentrations of >= 1400ppm ZDDP is actually causing issues.
Oils formulated in the 1970s were targeting a limit of 1200ppm at most.

Since most of the papers I have read on this subject come up with the same conclusions for 50+ years, I'm filing this one under "myths, and other urban legends".
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

ptashek

Goldie moved into her new home yesterday, finally having a permanent place 24/7.

I've used the occasion to take a shot of the underside, after a year and covering a good few thousand kilometres since  the restoration finished. She's still looking good, albeit the downpipes are rusted (another argument for stainless, I guess), and the diff housing has acquired a few stone chips and some surface rust.

The rust proofing has flowed nicely into all nooks and crannies, especially within range of the exhaust pipes.

(http://www.dropbox.com/s/rakozuvlbn5kcoo/IMG_20170627_211741~2.jpg?dl=1)
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

floyd111


ptashek

Quote from: floyd111 on 29 June 2017, 07:45 PM
So what's her new home?

A purpose built garage with workshop space and inspection pit, right in my backyard. It was on my to-do list for years.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

nathan

still looks great PT.
of interest, do you pop those wood blocks above the pit in case the hydro goes out and you get stuck in there?!
6.9 79 #6436
6.9 79 #6290
6.9 79 #6181
6.9 78 #4764
6.9 77 #3096
6.9 76 #1741
6.9 76 #0902
6.9 75 #0018

ptashek

Quote from: nathan on 30 June 2017, 07:30 PM
still looks great PT.
of interest, do you pop those wood blocks above the pit in case the hydro goes out and you get stuck in there?!

Mine's a standard SE, so no fear of hydro going out :) I use the timbers to cover the pit when not in use and just slide them aside when I'm working under the car.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

karmann_20v

Quote from: ptashek on 30 June 2017, 12:33 PM
Quote from: floyd111 on 29 June 2017, 07:45 PM
So what's her new home?

A purpose built garage with workshop space and inspection pit, right in my backyard. It was on my to-do list for years.

You sir are doing it right!

ptashek

This is a never ending story, so expect random resurrection of this thread :)

Things done recently:

- Installed rear speakers, with custom made adapters, bypassing the horrid fader potentiometer on the dash. Actually, I've removed it, and just plugged the hole with a plastic cap. Details posted at: https://zv9485.wordpress.com/2017/09/09/installing-rear-speakers/

- Replaced the fuel accumulator with a new one today. Turns out the old one was indeed a total dud, freely leaking fuel on the return pipe. So far, looks like her hot start issues are gone! My other spare is of the older type, with two outputs so I'll have no use for it - in case anyone's looking; it worked fine when taken off of the car ~2 years ago, and has been dry stored since.

The new type (A004760421) is made by a company called Woco in Czech Republic, and looks a little different than what went in at the factory:



1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

ptashek

Small part, huge price, massive difference!

Finally, no hot start issues. What's also gone is the slightly rough idle for a few seconds after a hot start, which I guess was because of the fuel pump re-pressurising the system.
The moral of the story is that no matter how good the rest of the fuel supply system is, a shot fuel accumulator will cause trouble - so always start any fixes here. Thanks to everyone who said so - I should've listened to you guys earlier :)
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

karmann_20v

Good to hear the hot starting issue is gone. Had the same issue on the red 450 that I sold this summer.

I wonder if Bosch discontinued this part, I remember most of the online part sources that I check frequently had many of them in stock. They are still available, but not all suppliers have leftover stock. Is it time to jump in and buy one just in case?

Also did you get the Czech made one from the MB dealer? (For the record, I consider the quality of anything Made in CZ on par w/German made).