Can anyone advise what would be the optimal rpm range for a 3005 cmc 617.952 Diesel Engine?

I have recently purchased a Mercedes Sel with this type of engine installed and it seems that all my front traction, gas-driving skills had become useless on this car. Most of the time I have to floor it to get this 2 ton beast rolling.. this rising another question - should I push the pedal all the way down quickly or gradually to let the engine pick it up more easily?

Assuming this 617 is a turbo:

Gradually come to full throttle until right before the turbo spools up', then slowly let off the throttle as the turbo kicks in.

I think the engine would be happiest above 2200-2400 RPM (starts building boost) up to 2800-3000, where max boost is said to be made.

Its a very flexible engine though. For the past week, I was cruising around and taking it easy, then yesterday, I had my foot to the floor all the time (250 miles) keeping up with some friends with rice burners. Most of the time spent in 3rd gear, over 3000 RPM while traveling through hilly terrain. A few hours later, I was sitting in traffic listening to the radio.

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1976 BMW 2002- 100k
1995 BMW 325i 175k
1984 Mercedes Benz 300D Turbo Diesel- 270,000 mi

1981 Mercedes Benz 240D- Estimated 300,000+ mi Returned to the earth

you mean your tach works?

wheh you say sel what do you mean?

is the car originally a gasser with the diesel installed later?

and what model is the chassis?

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.

Yes, it'a a MB 500 Sel gasser with a 617.952 Diesel engine installed. The engine is a classic, without turbo.

Previous owner loved to "push" it over 3000 rpm's, I feel ok with 1500 to 2500 rpm's (depending on the load) but I wonder which would be best for this engine in a W126 body?

you may have a stuck caliper as well as other problems with turbo and such.
pretty easy to check with the car supported on jack stands or just up in the air.
John

The 617.952 is a turbo diesel engine, originally installed in the W123 chassis. Earlier W116 chassis' (300SD) came with the original turbo diesel engine, the 617.950.

The non-turbo 3 liter diesel was the 617.912 in early W123s and W115s. I can't believe someone would have installed THAT slug in a SEL.

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'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

Hmm, I was under the impression that the xxx.952 was from the TD 123 chassis and the 2 meant it had the provisions in the head for the self leveling system... no big...
also, I second the opinion that the turbo should be in that chassis. MAN that is going to be slow without it. 2.45:1 rear, extra 120LBs from the length AND only 88HP? um, no? the extra 3gallons in the fuel tank is nice though. personally I would search out a 6cylinder 300 turbo for that car. get the little extra smoothness and power.
JMHO
John

Yes, a non-turbo diesel engine takes a little getting used to. I drove one for years (non-MB) and found that flooring it actually gave poor acceleration. Especially from a standstill.

You will find, with a little experimentation, that there is a sweet spot where the rpm's give you better performance. This might give you what you are looking for: Try starting out at about 2000 rpm and once you get forward momentum, then slowly put your foot into it and accelerate with higher rpms from there. I think you will suprised with the difference.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Mine seems to like 3000 rpm ...just shy of 130 kph.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

3,000+ RPM is fine... the redline is well beyond that. If the automatic transmission is working properly, then it will shift gears long before you reach dangerous RPMs anyway.

Throttle pedal technique when driving a diesel is quite different than that for a gasoline engine.

90% of the time, I floor it (or at least almost), and then gradually let off the pedal as you approach the desired speed. Quite the opposite of how you'd normally drive a gasser.

Mike

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1979 300 SD
350,000 miles
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1982 300D-gone---sold to a buddy
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1985 300TD
270,000 miles
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1994 E320
not my favorite, but the wife wanted it

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1500-2500 rpm's?? Bottoming out the engine will create carbon build up on piston crowns and valves, then unburnt fuel gets blown through for lack of complete combustion. Even with an automatic I'd be dropping gears instead of lugging along in traffic with the engine below 2k.

Forget all your gasoline engine driving habbits and dont listen to gasoline mechanic's advice either. With my 240D am constantly hammering the pedal to the floorboards. And when you get used to the diesel you wont want to drive anything else.

(edit: and give my regards to Bucharest..... We had somebody else from Romania in the Vintage Forum a few days ago, apparently there's alot of very serious MB fans in your neighborhood.

Same here, today I merged onto the freeway going 72mph coming off the onramp....needless to say I was almost flooring it, and I let it get up to 78mph in 3rd gear before I let it shift (I had it in S) so that was somewhere around 4400rpm or so.... It loves it up there! Mines super smooth at those rpms.... when on the freeway I usually go 75-85mph all the time, which is 3300-3800rpm or so, give or take. I can surely say that from the way I drive I have a completely carbon free engine. These diesels love to be driven hard, it keeps them healthy and happy. Just like people, lots of excercise = healthier

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Yep, and hammering down keeps it in gear too. Otherwise feathering and soft peddling the accelerator will cause it to grab the next higher gear that you probly dont want. Expect alot more special effects with the diesel than you get with gasoline engines. I scraped off my hood liner to INCREASE engine noise at high rpm's.

HAHAHA

Drive it hard. Pedal to the metal, just don't push so hard your foot goes through the floorboard.

3500 RPM going into 2nd 4000 RPM going into 3rd 4400 RPM going into 4th (at close to 80 MPH)

Enjoy