My rod bending 91 350SD has gave up on me. Engine is shot. The car is in mint condition and I hate to put her down. Now I know I could take out a mortgage and have another rod bending engine put but I notice that the 5 cyl turbo diesels of 300SD vintage are thousand$$ less. They are also far more reliable. I could live with the small power loss. Has anyone out there every made this conversion? How hard and what would be involved in making this swap? Any input, insight would be helpful.

It did make it to 231,000.

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1982 240D 370,000 daily driver, great car!
1983 300SD
1995 350SD gone to rod bending heaven.
1986 300SDL should have never sold it.
1995 2Dr 4x4 Tahoe with a highly modified 6.5 turbo diesel, 6in lift.

it being done just once. most think it is too much difference in controls etc. if it is feasible a lot of folks would like to do it.

another pretty good alternative would be to find a 3.0 liter shortblock and redo your motor with that. maybe you can find one with a bad head.

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.

There is a factory dealer installed 350SDL complete long block motor for $5K on ebay. It has just over 100K miles on it. It has the paperwork and the service record to verify it is of the newer designed ones sold in 2000 with the factory redesign to put a stop to their rod bending habit. Who knows the car below could just need a timing chain but I would bet the motor is toast like the seller mentions in the ad. Still the parts on that car are easily worth his low BIN asking price.

http://cgi.ebay.com/ebaymotors/Mercedes-Factory-350-6-cyl-Turbo-Diesel-126-Engine-SDL_W0QQitemZ8021393807QQcategoryZ33615QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

There is a short block also available from this seller for $5K. There are others selling short blocks but I did not read in their add that they replaced the rod-bender rods. There is a 1991 SDL with a bad timing chain for 2500 BIN price located in Ohio. If I had the loot I will have next month right now I would snag that critter and use my small truck to trailer it home. Then I would cover it and start scrounging for a remanufactured 350SDL motor like the one above on ebay for it. These 350 SDL cars should be worth some decent money as they are rare and some of the quicker and more desired MB diesel cars. You would have to get an estimate from your shop to repower your car with a different MB diesel motor. The cost to do that swap could come close to the cost of the better used long block for sale now on epay. Perhaps a few of the mechanics here can tell you what the swap to another motor will really cost you compared to buying a redesigned MB 350 motor used like the one on epay? Good luck with your car! John

Will the 3.5 head I have now work on the 3.0? I hadn't considered that. A 3.0 short block would be a lot less $$$ and should be a direct drop in right? Would I also be able to use the same accessories, A/C comp, PS, Alt. ect or do I need different brackets?

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1982 240D 370,000 daily driver, great car!
1983 300SD
1995 350SD gone to rod bending heaven.
1986 300SDL should have never sold it.
1995 2Dr 4x4 Tahoe with a highly modified 6.5 turbo diesel, 6in lift.

The 3.5 head will work on the 3.0. This is definitely the way to go. Can't confirm the bracket changes, if any, but, I would doubt that they would be significant.

Just curious...did the 3.4 bend a rod or was it some other terminal illness?

I keep an eye out for the 3.0 block because if i have one in reserve my 3.4 will never bend a rod.

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82 300D....went to MB heaven
90 350 SDL....excercising con rods

The number 1 & 2 cyl rods bent and 1 cyl egged shaped pretty bad.

__________________
1982 240D 370,000 daily driver, great car!
1983 300SD
1995 350SD gone to rod bending heaven.
1986 300SDL should have never sold it.
1995 2Dr 4x4 Tahoe with a highly modified 6.5 turbo diesel, 6in lift.

In my 3.0 search is there anything I should watchout for or stay away from?

__________________
1982 240D 370,000 daily driver, great car!
1983 300SD
1995 350SD gone to rod bending heaven.
1986 300SDL should have never sold it.
1995 2Dr 4x4 Tahoe with a highly modified 6.5 turbo diesel, 6in lift.

Cracked heads....I think #14 but you are putting the 3.5 heads on right?

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82 300D....went to MB heaven
90 350 SDL....excercising con rods

3.5 should have a No 17 correct? I'd pick up a 3.0 shortblock and go with it. I do not think you'd like a 617 in place of the 3.5L...

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

folks have reported bent rods on the mb replacement blocks. so it is questionable whether the "improved" rods address the real problem.

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.

That ebay seller seems to be offering an updated 3.5L short block for $3,500. That seems like a good way to go.

The car won't be worth anything come resale time with a non original engine, plus 350SDL's seem to comand a premium in the market.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Ok you guys have convinced me the 3.0 is the way to go. Stupid question but the 3.0 should mount up with my current transmission right? Also if I find a low mileage 3.0 that does not have the #14 bad head should I even bother changing the heads to my 3.5 head? Will the 3.5 head on the 3.0 give me any performance or efficiency advantages?

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1982 240D 370,000 daily driver, great car!
1983 300SD
1995 350SD gone to rod bending heaven.
1986 300SDL should have never sold it.
1995 2Dr 4x4 Tahoe with a highly modified 6.5 turbo diesel, 6in lift.

The transmission should give you no issues.

If the engine currently has a functioning head, even if it's a #14, just use it. Keep the head from the 3.5 (probably a #17) as a spare. You don't need to open up the 3.0 engine unless it's got some high miles and could use valves and guides.

Does anybody have a picture of a bent 3.5L rod from for an example?