I have a 1982 300TD, the engine was totally worn out - wouldn't start, no compression, massive blowby, and the local shops quoted around $4K to rebuild, the dealer quoted $6K for a rebuilt, so I put a 1992 Astrovan 4.3L V6 and T700R4 transmission in the car. I'm very pleased with it! It performs MUCH better than with the turbodiesel, and is very quiet and smooth now. It took a bit of detail work to get everything installed, but the V6 is a real good choice, as the motor mount brackets are in just the right place to fit right on the Mercedes engine mounts, and there's adequate clearance for the engine everywhere except the pan, which I had to take 2" off the front of. (Still holds more than the original with the oil cooler and lines) Also, I had to widen the tunnel about 2 1/2 " for transmission clearance at the bottom. This was accomplished by jacking the tunnel apart with an 8 ton jack- the pan folded into a nice Z fold on the passenger's side, and no cutting was necessary - i hammered the fold flat, and it's hardly noticeable. I used a piece of flat stock for the rear transmission mount. I installed the Mercedes crankshaft pickup and cruise control, so all the dash items work as per normal, except for the glow preheat lamp, which has now become the "service engine soon" lamp for the computer. The fuel economy is better than before on the highway, but around town it's a little less. (1750 rpm at 60mph) By careful shopping at the local wrecking yards, I was able to do the entire job for around $900... And that figure includes a new alternator, starter, and fuel pump. I think it's a real viable option for those mechanically inclined folks that are faced with an expensive engine job!

What a sacrilege!

P E H

Sacrilege???
 

I'm mostly responding to Mr Haiges... I think it would have been a much bigger sacrilege to part out the car, which was my other option- no way a retired person in my position could afford even the $4k repair job! The car still has all the "Mercedes Aura" anyone could wish for, it just now has power and runs quietly! Quite frankly, it's a much better vehicle than it was with the turbodiesel.

I called the dealership and a couple of shops to try and peddle the used turbodiesel and transmission only to find that there is absoloutely no market for them- the dealer said he couldn't get rid of them himself. Touring the local wrecking yards reveals lots of 280c and E engines, and some non turbo'ed and even a nice looking 380 engine, but no turbodiesels, so someone must want them, but I don't know who.

I didn't have to change out the tank or lines- to be legal you must run one more line from the existing vent, which is located near the tank, up to the charcoal cannister, which I retained from the Astrovan, to provide for emissions control of the vented gasoline fumes. I agree with TXBill that the 4.3 is a good engine- it's got the same bore and stroke as a 350, and is in fact a 350 with two cylinders removed. The engines give up to 200hp in the vortec editions, and are extremely reliable, possibly more so than a stressed out turbo engine. I did retain the tag on the back...

Richard W.

'82 300TD/4.3
'74 280c
'77 Jag XJ6L
'77 280Z

Good job, Richard. Did you take any pictures of the convertion. If soo, please post them.
Do you still have the old engine, I need a good head?

Conversions
 

Well Done, Richard. I'll bet you have a great feeling of accomplishment in preserving that old Benz in such a clean and reliable way. I can remember the literally hundreds of hours my buddy and I spent in our youth converting an old Jeep CJ-5 into a racing and off-roading monster. Tricked out Chevy 327, Borg-Warner tranny, fibreglas body, suspension, interior goodies, etc. It was a job that never seemed quite complete (we were always dreaming about something else we wanted to do to it), but it was so much fun and we learned so much.

Enjoy your ride!

gotta spare 300sd engine?
 

Actually, I want to do just the reverse conversion.

I have an 81 suburban that I use for towing. It's engine is tired and leaky. I though a nice 300sd engine & tranny to replace the 350 would be a very economical choice, fuel-wise for anything long haul. It's 0-60 will be poor at best under load, but the goal is to make it from point A to B cheaply, not quickly.

If you still have the dead motor & tranny, how much do you want for it and where are you?

-CTH

I read about that 380sec and the guy's offer to sell it. I wish I had the cash. I don't like the cars much post-1973. My 280c is one exception. A 126 coupe is the only other.

Anyway, Since there are desiel suburbans out there already, mine just becomes one of them. It doesn't pass inspection now anyway, so I'm not worried too much about the law. Besides, I like the kick that 7+liters of displacement provides. I'm not sure that I'll really love the 300sd motor, but it's better than the puddle of oil in the driveway I get now. If I get too lonesome for power, I'll just rebuild the 350 and put it back in.

The little engine that could :)
in more ways than one!

Richard I've done some engine swaps in the past and it's always been fun.

I'm impressed by your resourcefulness and it sounds like you did a good job. But it has NEVER crossed my mind to remove a longlife MB diesel and replace it with a short lived GM engine.

Good job,

That's pretty cool that you were able to do all that work yourself. It's pretty obvious that most people on this list don't like the idea of using non-mercedes engines in MB cars, but who am I to tell anybody what to do with their car. I think somebody else asked, but do you have pitures of the work you did? I think it would be really educational it you could post them for everyone to see. I wish I were as knowledgeable, and skilled working under the hood as you are to do that kind of work. Congratulations, and I am glad you like it, like you said it would have been horrible to have to part out a great car like that.

Larry,
Don't sell the 4.3L V6 short. It is just a 350 Chevy with two cylinders lopped off. The small block Chevy is one of the longest and most continuously improved engines around. They are very reliable. We have a Chevy S-10 with a 4.3; it is very smooth and torquey through a wide power band and gets 26 MPG highway. It is not unusual to get 200K from one with just routine to indifferent maintenance. Sounds like a good swap to me. There are lots of now elderly MB 123 diesels with tired engines around.

I saw in the local rag a while ago someone trying to sell a 300D with a Toyota engine in it, with a 5 speed.

For the Suburban, they’re pretty big, how about two 300SD motors?

Another conversion I've heard of is a Corvair engine in a VW bus. And a popular 350 conversion is from the old 350 diesel to a gas 350, it’s a bolt-in.

johngray,

I'm very familiar with the small block Chevy, maybe that's why my comments.

It's a 45 year old design. I've had plenty of them, and I've souped up plenty of them. One of the best is in my '88 Vette. I'm still not impressed, when compared to an MB engine. It takes many more dollars to upgrade one of these engines to the hp/cubic inch with the same durability and long life, than what an MB engine costs to begin with.

The only advantage to a small block Chevy as far as I'm concerned is that there are jillions of them out there, making parts and hopup pieces plentiful and cheap.

Prior to the small block, they're stovebolt six went all the way back to the twenties, and it's original form did not die until 1962, but that didn't make it great, just a plentiful, cheap built engine.

Power in numbers, but not in precision or impressive engineering.

Sorry to take issue, have a great day,

Larry, the 4.3 Chevy motor is one of the best built by General Motors these days. They have good torque and are very durable. The basic design goes back to 1955 but the refinement in design has made the Chevy v8s and V6s very durable and refined engines.
I,m looking forward to seeing the pictures of the 4.3 in 300TD swap. A swap like this would be very interesting for a 190E or 300E especially if you wanted a manual transmission (which are readily available) and would be an economicial performer.
I say this even though I believe Mercedes Benz engines to be the best but there are alternatives. Mercedes does make motorcycles, snow blowers, or lawn tractors.

I would not argue that the 4.3 and the V8's are the best built by GM. 'Nuff said.

Have a geat day,