question:
are there significant differences between '81-'84 300td turbo wagon heads and their 1980 300td non-turbo predecessors?
if so, what are the differences? are they nterchangable, or no?

Valves are different, turbo'd being sodium filled but as for the head itself, I don't know.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

The cam is diffrent too.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

did you buy that wagon on ebay, i wanted that thins so bad, to bad im on the right side in ohio, but i wouldnt have pd that much for it

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97 f350 crew cab diesel 4b4 86 f350 diesel 4b4
86 f250 diesel
81 mercedes 300sd
64 ihc emeryville

I am not sure on diesels but I think a gasser turbo has a lower compression ratio compared to a N/A gasser. Does this apply to diesels?

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'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

I venture a guess that the oil gallies aren't going to be the same, but it's just a guess.

Edit: Looks like I'm wrong. The part numbers are the same for the NAs and the turbos. 617 016 08 20. So and NA head will apprently mate to a turbo block and vise-versa.

The valves atleast have different part numbers for the NA and the turbo they are probably larger in the turbo, for more flow.
Exhaust NA valve - 616 050 00 27
Intake NA Valve - 616 053 03 01
Exhaust Turbo Valve - 617 050 00 27
Intake Turbo Vavle - 617 053 00 01

Are you thinking about swapping heads?

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You are comparing wagon to wagon, I assume. In the 123 wagons, the head has the SLS pump built into it. A sedan or coupe engine will not have the pump.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

No. MB actually raised the compression ratio on the turbo engines.

I thought they were essentially the same.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

if they did, they did it with the pistons, not the heads... there is no combustion chamber... totally flat head.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

The head itself is the same. The cam and cam towers are different on the later years because they gave it more lift to breath better. Other than that, except for the valves as already mentioned, they are the same.

If they did toy with compression ratio, and I'm not totally convinced they did, they did it with the prechambers.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

Correct, the head is completely flat. The only things that break the surface are the valves and prechamber. There is no combustion bowl like on a gas engine.

so, i guess the answer is: Nope. Not directly interchangeable...

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-lee
'83 300CDT (286k)

former proud owner of:
'85 mercedes euro 300TD
'80 mercedes 300TD
'77 mercedes 280e
'80 mercedes euro 250
'82 mercedes euro 250

No... they are the same part number so therefore the head itself is interchangible.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.