Whats the best Mercedes diesel and why?

Specifically only mechanical injection engines.

Priorities:

1. power/torque and reliability (equally) and engine can be modified if mods don't include tearing into the long block to replace pistons/con rods etc.

2. all other things (ease of availability, weight, size, whatever)

WOW.. Your gona open a can of worms with that one....

__________________
92 300D 2.5L OM602 OBK #59

I would say 617 for reliability and availability, and 603 for power, ease of modification and weight. Both do not require long-block modifications for power increase, but the head is a power limiter on the 617.

__________________
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

Why, this is an opinion based question, but if someone can't justify their opinion then its meaningless to me.

606.962 cause it the newest generation and most powerful engine complying with your critiria.

Easily modified by chipping it. Can go from 177hp upwards of 225hp if you want.

Course if it has anything to do with your diesel/gas swap thread you're gonna need to be a computer programmer or to dump the ECU and IP and stick a 603 IP on it instead. Then of course it can't be chipped. Should still have more HP than the others.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

If by mechanical you mean no computer control necessary, I say 603. Good durable engine will last many miles with minimal maintenance, quieter, more efficient, and smoother than the old iron-head engines, cross-flow head, hydraulic lifters, more power, ... if you consider the 606 to be mechanical, I'd take the 606 turbo over the 603 in a heartbeat, more fuel efficient and more power.

__________________

Gone to the dark side

- Jeff

IMO, the best Mercedes Diesel would be a combination of a 606 turbo engine and a 603 mechanical injection pump like Terry said. The 606 is an awesome engine - smooth, 24 valves and the 603 IP would give you mechanical simplicity and allow for traditional mods like timing advance and fueling.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

I have no doubt that this would be the best engine combination, I also have no doubt that an 606 turbo can't be found for less than 3500 dollars. A quick search of a junkyard parts locater found a couple 606 NA engines in the 2500-3000 dollar range.

So how about a comparison between the 617 and 603.

Which model year 603 is reliable?

Can the 603 be made as reliable as a 617?

It just occurs to me that if the 603 bends rods as it comes stock, than it can't be too reliable when pushed harder, at least not without tearing into the engine, to replace the rods.

Only the 603.97x 3.5L engines bend rods. The 603.96x 3.0L engines don't, but most from 86-87 (the years they were imported to the US) have the #14 head which has the tendency to crack if overheated. Any 603.96x with a #17 head or higher is a good engine. If you want a good mix of fuel efficiency and power, do a 602.96x. If solid fuel efficiency is what you're after, the 601 mated to a 5 speed offered in the 190D 2.2 nets upwards of 40mpg.

The 60x engines have a crossflow head which offers more power and efficiency over the 617 head.

The 617 will be more tolerant to abuse like overheating. But compared to the 60x it will be louder, less powerful, less efficient, and harder to modify.

And I agree with the 606 crowd on this thread...get a 606 with a 603 IP and you'll have an engine that will be hard to beat in the MB diesel lineup, save the CDI's.

__________________
Dale

http://i52.photobucket.com/albums/g1...MG_2277sig.jpg

1990 300D 2.5 Turbo -155k
2000 E430 - 103k
2014 Jeep Grand Cherokee Ecodiesel 4x4 - 11k
2014 VW Passat TDI SE - 7k Bro's Diesel
2006 E320 CDI - 128k Pop's Benz

Pre-glow - A moment of silence in honor of Rudolph Diesel

Ok, this is good info, especially on the 603.

If I can find a 603 3.0 at a good price I will probably buy it.

Whats the max reliable performance out of a 603 without, opening the block or doing anything crazy like spending 2k dollars on the injection pump.

I would do stuff like an intercooler, 3in turbo back exhaust, injectors, with and adjustments for more fuel, could make a custom exhaust manifold and use a properly matched turbo, maybe a gt25 .63 something cheap like that.

for me the 603, though more powerful and smoother is so much more delicate and high maintenance that I would much prefer the simpler, more durable, less fiinicky 617.

No comparison.

Tom W

__________________
[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.

Are we talking about Mercedes Benz only? Because if were not, my choice would be the 617 for the ultimate durability. Other than Benz, The Cummins 12 Valve P-7100 5.9 series diesel from late 1993 to early 1999 found in the Dodge Ram.

I'll take a 606 with a Myna pump over any of the others.

No doubt, I would too If they had an IP that was compatable with the 210 electronics!

We are talking about something affordable though...

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Other than few examples on this forum of cracked or leaking heads (rare and usually neglected/abused), I'm not aware of anything on the 603 that is more delicate or high-maintenance. Reading this forum has indicated that the 617 has maintenance issues, harder to start, glow-plug problems, valve adjustments, compression issues, oil pump and fuel pump issues, ... seems pretty much like the 617 gets a lot more press here for problems.

I read this forum regularly, and scan every time for anything 603 related. Other than constant warnings that the heads will crack and those who counter that they have original heads with 250,000 - 350,000 on them, pretty much nothing comes up. Same with the 124, same problems (HVAC, suspension, vacuum) as the 123, but those with the older iron sure swear they're junk after '85 LOL.

Seems that I read here that the IP is only good for about 180hp or so without substantial mods.

__________________

Gone to the dark side

- Jeff