Opinion: I have read lots of mixed opinions about turboing an NA engine. An acquaintance who is a very reputable Benz mechanic (strictly diesel) recently told me NOT to do it because the .95 engine incorporates a lower cylinder oiling/cooling capability that the .91 engine does not have. He indicated that turboing the .91 engine will burn the pistons up in it.

Background: I have an almost newly rebuilt 617.91 long block. I also have a fairly tired 617.95 short block. I also have all the ancillary turbo components to put on the .91 engine.

Issue/Question: Is this lower cylinder oiling/cooling capability of the .95 engine a bolt-on component that I can remove from bottom/inside of the .95 engine and install into the .91 engine? ... or is it something that is indiginous to the .95 engine that was originally machined into the block?

Issue/Question: Should I rebuild the tired .95 short block and install the top-end of the .91 engine onto the .95? What issues/ramifications are there in doing so?

Issue/Question: Should I just go ahead and turbo the .91 engine as it is and hope for the best? How long do the .91 engines typically last/run after converting to turbo?

The difference between the engines is more than just the oilers. It also has a different crank I think. If I had your choice, I wouldn't be turboing the NA, althought people have done it.

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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

I also believe the pistons themselves are different...perhaps in compression.

Hmmm, ... different crank? Anyone know the diff? Are pistons smaller? ... hence, will .91 head not work on .95 block if I rebuild the .95 lower end?

The OM 617.95x s have nitrided (hardened) cranks. The oil pumps are high volume, chain driven. Pistons built to take heat with oilers

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

but what about the heads? are they significantly different? I have a N/A wagon, and tons of turbo sedans... like to be able to swap over the head...and have turbo in my wagon.
?
John

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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!

I wagon needs the pump that only comes in the wagon version of the 617. Can't take a non wagon engine and put it in the agon without changing the rear SLS. Can't expect to change a 912 into a turbo'd engine without more work than it would take to completely rebuild a 952, and even if you did you'd end up with something that is still lesser in all ways than a original 95X.

Um, that's why I asked about the HEAD... the pump is in the head. if I can put the N/A head from the wagon, on the TURBO motor I could keep the pump...
John

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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!

Now can you transfer the Nitrited crank, the oilpump and the oil squirters into the healthy .91x block and rebuild it with turbo sleeves? because that what the question ultimately comes to.
if you do that i really don't see what could prevent you from using a turbo head ... on it.

Now turboing a NA head on a turbo block would be a challenge

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Aquilae non capunt muscas! (Eagles don't hunt flies!)


1979 300SD Black/Black MBtex239000mi
1983 300TD euro-NA. White/Olive Cloth-MBtex 201000mi. Fleet car of the USA embassy in Morocco
1983 240D Labrador Blue/Blue MBtex 161000mi

Don't forget sodium filled valves on the turbo engine.

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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

You cannot put the n/a wagon head on a turbo block and get away with it. If you really want a turbo wagon head I could get you one here in SF but it's gonna cost ya... shipping and pulling the part is not cheap.

ahh, prechamber differences and valve diffs... bummer. I may have to get a turbo wagon... or keep my mom's... how much do nice examples of the 82 and up wagons go for?
John

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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!

it would be easier to name the things that are the same. the head. that is about it. everything is significantly different. if you want a turbo find a good used one. lots cheaper than trying to convert one.

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.