Getting to Know You--The m180
 

For sure, engines have quirks, personalities, and histories. Part of getting to know (and love) my '66 230 is learning about the m180.945 that came with it.

For my class of car (110/111) I see that the straight six came in 4 displacements. Were these all m180 motors? Also, what characterizes the differences between the last three digits in the motor number? Were all the 180s alloy heads? Are all the heads interchangeable? Why does the 230 and the 230S have the same displacement and compression ratio, yet the 230S has more horsepower? Maybe the carburetion?

I'd love to hear from everyone having experience with these motors.

http://en.wikipedia.org/wiki/Mercedes-Benz_M180_engine

Here is a decent Wikipedia article on the facts and features about these engines to get you started.

On the M180 engines, power differences withing same displacements are mostly due to compression and carb differences. Also, the M180 2.2 engines had a double-row timing-chain, while the M180 2.3 engines used a single-row chain.

Happy Motoring, Mark

Really! So my 2.3 has a single row chain?

Why does that make me uncomfortable?

Yes, but don't worry, the short timing chain length won't be a problem.

It's more of an issue with some of the long timing chains used on the OHC V8s, than the relatively short chains on these sixes.

Happy Motoring, Mark

I owned a 230S for six years and never had a timing chain problem. The big thing is to make sure your tensioner is well-lubed, keep the oil clean.

Mine ran for 190,000 miles until someone ran into it parked and it was totaled.

The M180 started life in 1952 as the 220, in the ponton it was the 220a and then became the 220S with 7.6 compression ,different cam,single side plate on the block and twin carbs. Once the W111 came out ,the ponton engine was a still used but without sideplates and regular damper . By 1960 the m180 had the same carbs but a different cam and 8-1 compression heads were available to special order. Distributors changed a lot over the first 20 years from manual control of the timing for octane tuning to fully automatic for use with air con cars.
The good thing is that M127 engine uses a lot of parts like pistons and rods,crank that can be swapped in to make rebuilding easier and to use the better crank thrust bearing .
To improve performance on a m180 use the 230S 9.0-1 compression head with a cam marked 88 .
This cam has longer duration and deeper lift - more torque.
The chain wheel and tensioner need to be swapped of course.
The later twin carb manifolds marked 114 can be used with the weber conversion and W114 aircleaner for even more useable power and without a trade off for fuel consumption,unless you like gunning the car everywhere .
The greatest engine in the W111,actually W112 is the m189 3.0 liter. A real performance item.

isnt that the sl/gull wing motor?

(the w112 is a fave - only for the wealthy these days)

sorry for going offthread

MercMad--what are the side plates and the damper for?

Also, and in general, why were these heads cast in alloy instead of cast iron?

The water jackets on the first series of m180 engines had a plate on each side held on with LOTS of allen bolts ,These plates rust out are impossible to find new . This was necessary because Daimler was still getting back up from WW2 and couldn't yet afford to cast a block with the water jackets as a whole.
The damper is the vibration damper on the crank shaft . The early engines have a spring loaded device,invented by Lanchester in England .
The later engines have a rubber cored damper,pretty much the same as most engines.
The first pic with the twin carbs is a early 1959 W111 finny engine . Note it only has the freeze plates on the block,no sideplates and the small damper .
Second picture is of the first M180 built,in 1946 . Single carbed ,side plates on the block etc.
Alloy heads are lighter and give better heat transfer . Mercedes Engines ,except the sidevalve six cylinder 230's of the 1930's are all Alloy heads.

The gull wing is a cast iron block M186 . The W112 is a similar engine but with alloy block and plugs in the head.. Most internal parts and the heads interchange though. The gull wing had injection into the block via the spark plug holes. This meant that the head had to have plug holes ,so the m189 head was designed for that purpose.
I have several here and i'm tossing up what to do with them. i have a salt lake racing car which may get a m189 engine yet...:cool:

The first W187s with 180.920 engines had cast iron heads.
Later production 180.920s and everything that followed used aluminum.
The 180 engine was used in the unimog 404 till 1980.