300TD basic questions? - PeachParts Mercedes-Benz Forum

dieselcruiserhe · #1 09-23-2002, 01:47 PM

Hi all,
I run a web site at http://www.cisautoweb.com which is dedicated to diesel engine conversions in Toyota Land Cruisers. Recently I've bumped into a guy in a California who's telling me diesels from 300TDs are a great conversion into a Toyota Land Cruiser for a whole bunch of reasons. I guess I'm starting this thread to get your opinions and any relevant information that comes out of it I'll post to the site...

So, here are my questions:
1) I'm told "the engine from the 300TD is a great candidate for a swap" for many reasons, all of which I don't want to completely spell out but it sounds interesting! However, I'm not sure of different engines available from what years and what different advantages different models might have. Can someone lay out what models were available in which cars from what years?

2) I'm aware the HP output is somewhere near 130. However, I was not able to find much information about the torque specs. Does anyone know what they are off hand at factory settings?

3) Power output I'm looking for is somewhere near 325 ft/lbs of torque and whatever horsepower possible over 125, hopefully somewhere aroud 160 when tweaked. I'm told that the Benz 300TD engines can be tweaked (I'm not sure if this is via boost, fuel pump, or both?) to over 500 ft/lbs of torque. Is anyone familiar with the best way to tweak this engine?

4) Finally, I am not a power junky, I'm just looking to power a vehicle adequately that will weigh over 6-7000 lbs. (A full size 80 series Toyota Land Cruiser wagon). With tweaking these engines is there significant loss in relability or is the engine compromised to a level that could be considered damaging to the engine. For example tweaking Toyota diesels does in fact compromise their normally very long lived lives. Likewise I hear Mercedez Benzes have excellent reputations for longevity as well and I'm certainly interested in any and all information.

5) Does anyone have any links to some basic general sites that go over the engine?

And final two questions:
6) Direct or indirect injection?
7) Rotary or inline pump?

Thanks!

#2 09-23-2002, 04:38 PM

The motor I think you are talking about is the 617.952 motor. 5 pots, Garrett turbocharger. There is also a OM603 motor, but with 6 pots, and aluminum head. The 617 is all iron. In top 1985 factory spec, it puts out 125 hp. Most put out 120-123 depending on year. Not totally sure on torque. I do know these motors were used in Unimogs and G-wagens of the time, and actually share heritage with a refigerator truck motor from the 50's. Very simple motors. I think they would pair nicely with the Land Cruiser for its strong, much like the Toyota. They can be tweeked, but to the extent of how reliable they remain, has yet to be seen. They can be tweeked on boost, pump, etc. Various tricks to doing this as a search will find. Good luck! I would love to hear more of your efforts....

#3 09-23-2002, 05:25 PM

Oh, almost forgot, these motors (all except the new CDIs) have indirect injection with an inline pump. The 617 was built between 1975-1985: 1975-1981 standard, 1977-1985 turbocharged... The OM603 3.0 was offered in 1986 and 1987 only, some years of which had trap-oxydizer problems, all of which may be prone to head warping if over-heated. A good motor in 617 form can go 500k or more, a good 603 maybe a little less. Again, these are averages, not exceptions. (I don't want to hear how your Uncle's 603 did 800k, its rare!)

bennett · #4 09-23-2002, 08:30 PM

Welcome Dieselcrusierhead... I am a newbie too!

interesting thread ......I'll keep an eye on it.

bennett

PS ....already staring at two of those 617s..." all Iron"

psfred · #5 09-23-2002, 09:13 PM

All the MB engines turn out substantially less than 325 ft/lbs of torque -- more like 170 or so. The 603 puts out 149 hp and 195 ft/lbs torque. The 3.5 L 603 version puts out more, but will be prohibitively expensive.

The 617 is a great reliable engine. However, you may feel seriously short on hp with it. It will work fine in lower gears, but you won't get good acceleration with it.

Peter

dieselcruiserhe · #6 09-24-2002, 02:39 PM

Quote:

Originally posted by psfred
All the MB engines turn out substantially less than 325 ft/lbs of torque -- more like 170 or so. The 603 puts out 149 hp and 195 ft/lbs torque. The 3.5 L 603 version puts out more, but will be prohibitively expensive.

The 617 is a great reliable engine. However, you may feel seriously short on hp with it. It will work fine in lower gears, but you won't get good acceleration with it.

Peter

Thanks Peter. In fact a 6000lb+ Land Cruiser I've already owned came equipped from the factory with an engine that has 107hp and 177 ft/lbs of torque! So one of these engines could power the vehicle I'm thinking of but admittedly it was a dog. I've heard that the Benz engines are quite easy to "tweak" to have higher horsepower, I did like those images of the adjustable boost control. However I'm looking for solid information, my guess is it's a combination between boost and added fuel. For example, is there a simple way to turn up the fuel on any of these Benz inline pumps (or are they Bosch pumps?)?, and I'm still interested in longevety issues when cranked up. I have a choise between two engines, the Benz that I would like mostly because it's smooth and seemingly very reliable and can be found used cheap. The other is an expensive Isuzu engine that already puts out the power I'm looking for, but is four cyl, and the closest I can find in the package I need to a Benz engine, but does not have the higher RPMs, 5 cyl, etc etc.

For example a Cummins 4BT 4 cyl direct inject diesel can be cranked up from 250 ft/lbs to 500 ft/lbs with very little long term wear and tear. They are very beefy engines (basically 4 cyl versions of the 6BT found in Dodge trucks that is commonly turned up for more power as well).

Thanks, and all past and further comments appreciated!

Andre

psfred · #7 09-24-2002, 08:07 PM

Andre:

It's difficult to squeeze more hp out of an MB diesel without shortinging life, MB usually does a pretty good job as it is.

You can raise the boost as far as you dare with an aftermarket boost controller -- this will give you more hp, and the added fuel is already added by the ALDA (connected to the boost system). No way you're going to double the hp, though -- remember, this is a 3.0 liter diesel, you can't expect huge hp.

Properly maintained, they will live forever, though.

Peter

dieselcruiserhe · #8 09-25-2002, 02:26 PM

Thanks Peter, appreciated...!

Not trying to double the horse power, trying to (almost) double the torque! As we speak Bennett (who replied above) just got about 4 running Benz engines, 3 turbo and 1 240D (which I always loved the look of). I guess that's why I'm here - seems like they can be had cheap

The Warden · #9 09-25-2002, 02:50 PM

Quote:

Originally posted by dieselcruiserhe
For example a Cummins 4BT 4 cyl direct inject diesel can be cranked up from 250 ft/lbs to 500 ft/lbs with very little long term wear and tear. They are very beefy engines (basically 4 cyl versions of the 6BT found in Dodge trucks that is commonly turned up for more power as well).

Y'know, you might wind up having better results with the 4BT (or would it be possible to put a 6BT in the Land Cruiser, or is there not enough space?). I've been told that a lot of GM roach-coach type vans in the '80's were powered by a 4BT with a TH400 auto behind it. I don't know how easily found they are, though. Might wind up being around the same price as a 617, as well...

Just a thought...good luck and welcome aboard! I'll admit that I dont think any Benz diesel would be wonderfully suited for a truck, but it does make a great car engine.

I've never had a complaint about not enough power in my 300D, but I don't think I would be very happy with it were it in my F-250...

dieselcruiserhe · #10 09-25-2002, 03:20 PM

Well thanks for the insightful information, I have a strange feeling unfortunately that I'm not going to be sticking around too long (as I quest away for a Diesel and it looks like the Isuzu 4BD1T is the best option). I've well researched Cummins 6AT, 4BT, and 6BT into cruisers. If you want to see picts of one shoehorned into a 60 series (boxy wagon) Land Cruiser take a look on my web site! I'd personally go with the 4BT, it can get exactly the power I'm looking for at approx 130hp, 300ft/lbs quite easily. Only problem is their noisy buggers. But running them on vegetable oil should quiet it down a little

The Isuzu is quiet and smooth, found in NPR trucks which is now, I'm told, the most popular box truck on the market. Problem is they don't die so I haven't been able to find too many in the yards. The 4BTs / GM / Grumman box trucks are all over the place, you gotta know where to look but you can find them. I've found some with reasonably low miles (-130K) with 100 day warantees from frist start all over the country. And Bennett (the BB poster above) found one behind a Chinese restaurant that we were going to try to scam for free. I'll probably have it rebuilt anyways but it might be an unneccessary cost as it looks like the tranny's blown, not the engine.

Anyways, thanks for the input. Diesel engine searching away rattle rattle rattle!

Andre

Wasuchi · #11 09-25-2002, 07:34 PM

Try this site for the Isuzu or just about any other truck engine.

http://www.trucks.com/parts_inventory.asp?makeSearch=ISUZU&category=11

bennett · #12 09-25-2002, 09:53 PM

Wow nice link..........thanks