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A friend of mine is offering me his 1984 Euro Spec 300D Non turbo 4 speed manual. What would it take to install a 617 turbo engine into this car? What would need to be changed beside the engine? Is it worth it? I haven't driven his Non turbo 4 speed, How do they run compared to a turbo automatic?
 

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1981 W123 300D non turbo, 1992 190E 1.8 <=> 2.0
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I'd drive it first. It might not be as bad as you think.

Assuming you want to keep the manual transmission =>

If you are putting in a turbo engine that was mated to an automatic then you need to save the (very desirable) non turbo flywheel and put that on the turbo engine.

One thing that you might want to do is fit the turbo radiator with an expansion tank (block off the transmission oil cooler section) - non turbo's don't have the expansion tank set up.

You might have trouble with the engine shocks - I think they are in a slightly different position on the turbo engine because of the slightly different oil pump / upper oil pan housing.

Vaccum system will need slight modifcation from an automatic set up to a manual set up.

The only other thing that comes to mind is perhaps the little bit of reflective stuff on the bonnet sound insulation - just above the turbo...

...before fitting the turbo engine make sure you have a nice refurbished starter in place before you fit it to the car - one of the many beniefits of the non-turbo engine is that you don't have a terrible time removing starters!
 

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1977 300D, 1984 300D.
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Don't forget to change the differential and speedo.

Exhaust is different too.
isn't engine rpm range exactly the same between turbo and non turbo engines?

diff ratio should be matched to transmission, not engine. likewise, speedo is driven by trans, so unless you are swapping an auto those should be the same.
 

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2001 Volvo V40
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isn't engine rpm range exactly the same between turbo and non turbo engines?

diff ratio should be matched to transmission, not engine. likewise, speedo is driven by trans, so unless you are swapping an auto those should be the same.
The rpm range is indeed the same on all the OM61X diesels: 700-800 rpm at idle and 4800-5200 maximum speed unloaded. But the 300 turbodiesel has more power and torque, so you can gear it longer. MB did this by changing the ratio on the differential: 200D had a 3.92 ratio, the most powerful diesel of the range the 300 turbodiesel had 3.07 or 2.88 (in 1985). This ratio was the same for every transmission used, whether four-speed manual, five-speed manual or automatic.

MB did use different differential ratios depending on transmission when they introduced the W201 and W124 models, but not on the W123.

The speedo is driven by the output shaft of the transmission. The distance travelled at every revolution of the output shaft differs depending on differential ratio. The speedo is mated to the differential ratio.
 

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1977 300D, 1984 300D.
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Right, changing the diff would be benificial, but isn't a necessity.

Than again, again after taking the 300d non turbo on the freeway, maybe it is necessary haha.
 

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1978 mercedes 300D "silver streak" 2000 Mercedes ML320 1994 W124 Mercedes e500
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If you are putting in a turbo engine that was mated to an automatic then you need to save the (very desirable) non turbo flywheel and put that on the turbo engine.
kind of a newbie question here but why is the non-turbo flywheel better? is it lighter?
 

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'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
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Because the automatic flywheel is different to the manual flywheel, and the turbodiesel was never sold with a manual transmission - not even in Europe.

Also, it's the flywheel-balancer pair, the two work together.
 

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84 300TD, 2004 E320 wagon, 2006 CLS55,
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kind of a newbie question here but why is the non-turbo flywheel better? is it lighter?
The manual transmission flywheel for the four cylinder 616 (240D) is lighter and when used on a 617 (five cylinder) with a manual transmission it has a tendency to create a buzz around 1550-1700 rpm. The 617 flywheel is 32 pounds while the 616 is 24 pounds IIRC. For those converting a 617 to a manual transmission the 617 flywheel is highly desired. If you cannot find or afford a 617 you use a 616 and try to get around the buzzing issue.
 
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