Engine weights

[Jamie-M]

Hi,

I’m trying to find a W123 engine that weighs similar to the M111 230 kompressor motor. I think that weighs about 360lbs / 163kg from reading a thread somewhere.

I’m putting the kompressor into a W123 coupe and need to get suitable springs to deal with the weight difference from the original M102.

Thanks

 

[Jamie-M]

I meant to add that if anyone knows or has an idea of the weights of the various engine types that went into the W123 would they be able to let me know.

Any help greatly appreciated!

 

[Bellow]

I'm guessing that that kind of info is going to be hard to obtain. But you can use the existing springs as a weighing scale.
Measure the ride height as it is with the original engine and again with the engine removed. Subtract the one from the other and you now have how far the weight of that engine compresses the springs (or a relative measure as lever ratios are at play). Repeat with the new engine installed and you have a percentage difference by which the spring rate needs to be altered - if at all.

 

[Jamie-M]

Thanks for that, ideal way of doing it…however the old lump is already out and the new one in. I think the weight difference is about 45kg. Maybe not that much to worry about?

 

[MrGreedy]

Assuming the car is 2,000 kgs, for the sake of 5% weight difference (half a person?) I wouldn't bother.


Strictly to March performance, damping rate should be altered with spring rate (strength). This sounds very complicated and potentially expensive, so stick with what you have.

If you can get measure the height difference as suggested above, and then get some of the rubber suspension cups in a slightly different height, that will suffice I'd suggest.


The rubber cups are on various Mercs, and sit under or on top of the sprint. They have various dots on them to indicate height. You buy them from Merc but I don't know if they were fitted to your car.
It fact, they might just be for the rears? I'm unfamiliar with your setup, but basically, if you can make some easy and cheap ride height adjustment, I'd stick with that and nothing more.


Good luck and tell us how this goes please OP

 

[Jamie-M]

Thanks for that, you’re right, 45kg isn’t really a huge difference so I’ll stick to 230ce springs.

 

[MrGreedy]

Just re-read this. Apologies for the terrible 'spelling' in the previous post. I replied on my mobile and autocorrect was obviously having a field day!

As suggested, ride height is probably key here.
If it's moved a few mm, then I wouldn't worry about it. If it's moving 10+mm, then maybe look to address it (bearing in mind, people go for 15mm, 30mm drops when they're lowering cars all the time).
Thinking about how much the car sinks when I get in, I can't imagine the ride height is affected much by 45kgs

 

[carat 3.6]

The weight difference wont make any noticeable change. I took a m102 out of a 190e and replaced it with an m111, no change in ride height that I could see.

 

[Jamie-M]

Thanks for that, I’ve ordered some Spax springs for it, should ride lovely