W123 later engine ?

[alk]

I own a 1985 230e W123 4 door sedan. I recently had a lot of work done to the body and i should now have a rust free car. i did end up using some after market panels so my car is far from "all original" but it should be healthy to drive for the next few years.
I enjoy driving it but, looking at the future, with emissions restrictions etc, i thought about looking into how a car like this can be made cleaner. Although I don't drive fast, putting a w123 on a motorway nowadays is can be a struggle when using slip roads etc..modern cars accelerate so much better ..
the 2.3 petrol engine is great but mine has 131.000 miles without very much care and will probably need a serious reconditioning at some stage.
I wanted to ask if a later engine can be fitted into a w123, a cleaner, newer engine and if there is a little more extra power even better.I know that this probably more complicated than an engine swap but was wondering if this is a realistic possibility, if a decent 2nd hand engine was found.
To be clear, i am not looking to modify my car into something sporty and fast, just asking if there is a more practical and efficient engine i could fit without spending millions..
i also don't know how this would affect insurance.

many thanks

 

[grober]

The obvious choice would be the later version of the M102* with the KE jetronic injection system complete with mixture control by lambda sensor to allow fitment of a catalytic convertor running on unleaded--think the earlier engines had hardened valve seats so no problem there. The obvious next step would be an normally aspirated M111 twin cam at 2.2 litre 150 bhp and if really bold a 230 kompressor 180 bhp version of the same engine. They would fit easily enough but you are into major changes in vehicle electronics and fuelling.
* even if only rebuilding your old engine a wise upgrade is to use the later duplex chain timing gear to extend life.

 

[alabbasi]

Early M104 DOHC engine with CIS-E or M117 5.6 V8 (for merging). Both should bolt right in.

 

[Bellow]

This....

They would fit easily enough but you are into major changes in vehicle electronics and fuelling.

.... inevitably rears its head in transplant discussions and can be particularly thorny. Larger engines really need the appropriate gearing which may be a diff (that may or may not physically fit).

In your (OP) case I'd run it as it is. The motor at that mileage will be fine though expect to lift the head at some point to replace valve stem seals at which point a bit of 'tidying up' can be accomplished.
In any case, the car's emission rating (so to speak) can't be altered to permit access to cities where it will be excluded. Enjoy it as it is and let your contribution to green-ness be walking the shorter trips.

 

[clk208]

Hopefully if the rules stay the same once it hits 40 years old it will be exempt from the various low emissions zones anyway. Not long to go.

Has to be better than the 10 year old worn out VW diesels you always see which even when working properly produced 80 times their quoted emissions.

Regards your need for a bit more speed, a good tune up and service might restore a few lost horses and make the performance more acceptable?

 

[alk]

Thank you for your replies
Regarding its own engine: I bought the car with very little history so i presume that the engine was not looked after religiously.i did my best with regular oil changes etc in the last decade i own it but I think it probably has lost some of its power.
I understand that an engine upgrade is probably a complicated matter and i agree, probably not worth the trouble.
I will look for a mechanic to do some work on the engine soon.
thanks very much

 

[Bellow]

Thank you for your replies
Regarding its own engine: I bought the car with very little history so i presume that the engine was not looked after religiously.i did my best with regular oil changes etc in the last decade i own it but I think it probably has lost some of its power.
I understand that an engine upgrade is probably a complicated matter and i agree, probably not worth the trouble.
I will look for a mechanic to do some work on the engine soon.
thanks very much

It's a tough engine that four pot - my 200 did 230k miles.
A compression test if you're concerned is easily accomplished. A compression tester should be buyable for circa £20 so an easy DIY proposition. The absolute values aren't critical - what you look for is a balance across all cylinders. If they are all low you can calibrate the tester on a known to be good engine (even a strimmer engine - look for 6 bar there). Compression testing tests both ring/cylinder condition and valve leakage. If readings are low, an improvised leak down test can usually identify if the problem is with the bores or valves. If the latter, a head off job and some TLC lapping the valves can work wonders. A bit of cleaning up of the ports and new valve stem seals while you're at it and if the bottom end is good - you're good for thousands more miles.