300d na into the 85 sd? - PeachParts Mercedes-Benz Forum

t walgamuth · #1 08-07-2010, 01:24 PM

I am pondering what to do with my newest benz acquisition, the 85 300sd. My original plan was to pull the 300 na euro and five speed from my 83 240 body and drop it into the sd. The sd is so nice inside and the tranny seems good that I am contemplating other options including the 300 na motor into the sd keeping the sd tranny. Would that bolt up and work ok?

Actros617 · #2 08-07-2010, 01:42 PM

Get a Turbo OM617 or a OM603, your not going to go anywhere with that Naturally aspirated engine in that 300SD body.

t walgamuth · #3 08-07-2010, 01:47 PM

I am aware of the performance implications. The question was about the compatability.

ashedd · #4 08-07-2010, 01:57 PM

Just give the SD to me and be over it.

sixto · #5 08-07-2010, 02:06 PM

I don't think the 123 pedal assembly in plug-n-play in a 126.

Sixto
87 300D

DieselForLife · #6 08-07-2010, 02:15 PM

MB developed the turbo engine specifically for the 300SD because performance with the non-turbo was unacceptable in the heavier body.

However, yes, the engine will physically fit in the vehicle but you will need to make or cut a diveshaft to fit (EDIT) with a manual transmission.

duxthe1 · #7 08-07-2010, 02:19 PM

With the SD tranny it will be a direct drop in. That said you will regret every second of it as you mash the accelerator and wait till next tuesday for the car to go. The SD is geared for the turbo motor and if you thought the NA was slow in the lighter body with lower gearing...... lets just say you'll be fighting the urge to get out and push.

t walgamuth · #8 08-07-2010, 02:44 PM

Thanks for all the advice on not doing it, and I may well follow that advice.

Thanks even more for answering the question asked!

My first effort will be to try to get the motor going good without changing it out. I have not given up on that as yet.

Hit Man X · #9 08-07-2010, 03:40 PM

Compression test then go from there.

pawoSD · #10 08-07-2010, 04:39 PM

Quote:

Originally Posted by DieselForLife

MB developed the turbo engine specifically for the 300SD because performance with the non-turbo was unacceptable in the heavier body.

However, yes, the engine will physically fit in the vehicle but you will need to make or cut a diveshaft to fit (EDIT) with a manual transmission.

Not really, the W126 weighs only slightly more than the W123. And just as many if not more W123's came with the turbo 617 than W126's. There were about 6 engine options used in the W126, and only 4 in the W123.

sixto · #11 08-07-2010, 05:02 PM

There were more than 4 engines offered in the W123 over the years: M115 2.0 & 2.3, M102 2.0 & 2.3, M123, M110 carb & FI, OM615 2.0 & 2.2, OM616, OM617 NA & turbo.

The 126 saw the M110 carb & FI, M103 2.6 & 3.0, M116 3.8 & 4.2, M117 5.0 & 5.6, OM617, OM603 3.0 & 3.5.

Granted not all engines were available at the same time, that's still fairly even engine variation for each.

Sixto
87 300D

t walgamuth · #12 08-07-2010, 06:54 PM

My 300 na is a euro and even with a 307 diff the car will go 100. The book only claims 103 or so for the turbo 126 sd, so I am not giving up all that much perhaps. I don't think I wanna pull take offs though with the 288 diff in the 85 with more weight than I have now.

If I decide to go with a stick conversion I will probably change the diff too.

That would be whether I go with the na engine or the turbo engine.

But with the automatic I don't think it will make all that much difference whether its turbo or not. The turbos are notoriously sluggish off the line compared to the na motors.

t walgamuth · #13 08-07-2010, 06:55 PM

Quote:

Originally Posted by Hit Man X

Compression test then go from there.

Actually today it sounded like a bottom end problem.

t walgamuth · #14 08-08-2010, 07:04 AM

I am trying to convince my lovely #4 daughter to let me take the fresh motor out of her increasingly shaggy 82 300cd and put in the new brown sd.

She really is emotionally attached to the cd even though she is partially sitting on bare foam now the leather has fallen apart so comprehensively.

Maybe I will tell her that I will redo the motor from the sd and put it into the cd this winter.

DieselForLife · #15 08-08-2010, 07:09 AM

Quote:

Originally Posted by pawoSD

Not really, the W126 weighs only slightly more than the W123.

Not really. There is more than one S-Class chassis. When was the OM617a Made again?

Quote:

My 300 na is a euro and even with a 307 diff the car will go 100. The book only claims 103 or so for the turbo 126 sd, so I am not giving up all that much perhaps.

In terms of absolute speed, right. However the time your euro needs to get to 100 is much longer than the 103 of the SD.

Quote:

She really is emotionally attached to the cd even though she is partially sitting on bare foam now the leather has fallen apart so comprehensively.

If only we all had kids that could learn to love cars so much.