The MB little D's are just as good as the big D's. A good diesel goes 400-500K before it needs any major work assuming it has been taken care of throughout its life. My uncle drives for WalMart and 500-800K miles is common on the big D's just for longhaul distribution. Leasing is push down the milage but all big D's have one some two turbo..... ummm a mercedes with twin turbos, now were're takin.

Seriously, I think everything else will get replace on the car before you do anything major to a MB diesel motor.

Morph

My vote for the best 300D is the 90-93 variety......airbags,better handling,smoother engine,better accelerations,quiter ,better mileage
I had one that I drove 208K and never put anything in it except glowplugs and regualtor


Warren
1992 300SD 124K
Columbus Ohio
turner@greif.com

What is best is what makes you the happiest.For me It is the non turbo.Best to all.Michael R.

I do not agree on the 83 being the "best." While some may beg to disagree, I hold the 85 as the best year for the 123. Not only was it the last, but if you ask any mechanic, it has all the bugs worked out and has many improvements over the prior years. Among the improvements: vacume pump, fuel pump, cruise control configuration, and last but not least, the transmission modulation. There are a few minor touches, but if you ask any mechanic/Mercedes buff, they will contend the 1985 as best/final/most desired. (It is VERY hard to argue these points.)

are you saying you believe the 123 superior to the 124 of '87 and 90-93?????


Warren
1992 300SD 124K
Columbus Ohio
turner@greif.com

The issue is w123 Diesel, or so I thought... Best 300D? In MY OPINION, yes! While most will argue a newer 603 block is a better car (and in most cases it is) it lacks in soul and diesel aura. Basically, I don't find the shape as pretty as the 123, while the 124 is a beautiful looking contemporary classic, the 123 is just plain classic. It is the last of the old world Benzes, old world interiors and materials.

While they (123s) are harder to service (valves and what not) and not as fast (603s put out more power) they are louder, punchier and more like a diesel truck! I think they have more character, they epitomize the diesel car in America. While they don't go as fast, have bad drag, and are harder to service, the w123 has a special place for MANY mechanics/owners.

The curves, the chrome, the noise. It all counts in my book. I like to think about it like the WWII Bombers, B17 and B22. While the B22 was a better plane on paper, the B17 won the hearts and minds of all who worked on them/flew them, and came to symbolize an era. I feel the 123 does just that.

Because really, if I wanted a fast w124, I'd get a 300E- great economy, MUCH more power and NO TRAP!

Bill a turbo version of the 123 is made no stronger than the non turbo version.

Sw please show the specs that illustrate the hevier parts in a turbo.As far as the oil jets to the pistons,the non turbo has that.Best regards Michael R.

Sorry Mike, you are wrong. It is known fact that the 617.952 block is a stronger, heavier block. The cc's are a little lower (due to the turbo) but the block'l lower end was reinforced, along with the crank, the cam and the main bearings. Mercedes HAD to reinforce the block due to the added stresses the Garret turbo charger added. If you were to put a turbo on to a lessor standard 617 block, it would blow it to shreds internally! While I don't have specs to support, I AM TELLING YOU the 616.952 motor is more stronger than a standard 617. Just stating facts! Give me time, I will get you specs!

randall,I defer to your knowledge.Best regards Michael R.

IMHO, here are the relevant facts I've gleaned:

The 617 turbo engine has a chain driven high output oil pump to drive the oil jets. The non-turbo engine doesn't have the jets, doesn't have the oil holes in the pistons, and a few other odds and ends. The non-turbo oil pump is driven off the IP.

Piston pins are larger in the turbo, bore is different (smaller or larger, depending upon exact engine), but the crank is the same.

I don't think MB "beefed up" the lower end -- I suspect it was originally stressed for a turbo, as the development engine (the C111 test car) was turbocharged at more than one atmosphere!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Bill:

I guess that is why there are those three numbers after the 617!

I have no idea -- they are all the same size as far as I know. Maybe deeper nitriding on the more powerful ones, but different alloy? Who knows. The only way to find out would be to check part numbers for the various 617.xxx engines and see if they are different.

Moot point for me, as I have a 615 and a 603!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

FYI:

As it's been said already, the oil jets are non existant in the na engine. Have a look at the pictures below taken from page 45 of my 1982 sales brochure:

The circled area on the left illustrates the oil jet and the piston. The circled area on the right shows where the oil jets are located in the block. The picture below it (b&w) illustrates the na engine. I don't see any oil jets.




Also, from the PP/IMPCO catalog, it seems that the non turbo 300D and the 240D have the same part number for the pistons. If anyone has info from MB to prove that the na engines have oil cooled pistons, please post it, as it would be a learning experience for me and a lot of us.

Regarding the issue of which engine weighs more, page 7 (covering the 300D turbodiesel) of the brochure states:

"The turbodiesel transformation brings a 45 percent power increase, at the cost of less than five percent more vehicle weight."

I can't find anything in there that says the SD and D engines are different. I know the oil filter hosings are different. The crank might be the same in both but the one in the trubo is nitrided for increased hardness and fatiigue strength.

__________________
2001 Dodge Ram 2500 Cummins Turbo Diesel - 4x4, auto, 3.54 gears, long bed
-------------------------------------
'92 300D 2.5 Turbodiesel - sold
'83 300D Turbodiesel - 4 speed manual/2.88 diff - sold
'87 300D Turbodiesel - sold
'82 300D Turbodiesel - sold

I quite enjoy the 120-mph speedo found on my 1983 300D. I had it at 110-mph the other week. The car felt as tight with the ground as it does at 80-mph.

I prefer the turbo-diesels. 1982-1985.

Turbo's and diesels are a natural together. Diesels are much more efficient with them. Now that being said, I have a NA diesel in my CD. Not having a turbo is not a good reason to not buy one, as these w123's are getting harder to find with good bodies. I really like this NA engine. Thought about building up a 952 for it, but it really does run to good, so I'm leaving it as is. I do like the better milage of the turbo's though. 28-29 mpg is about the best I can do .

Have a nice weekend