127 II and 127 III

[folo86]

what differences there are between M127II and M127III?   

The engine 127.982.10.021862 can be mounted on a Mercedes 230 SL Pagoda of 1963?   

[114015]

Hello Folo,

Yes, it <<could>> .
The M127 II is the original 230 SL engine, and the engine serial numbers always start with 127.981-

The M127III is the regular 220 SE engine (from 1959 - 1965, serial numbers start with 127.982-) of the W111 sedan chassis (fintail) only. W111 Coupés and Convertibles had the M127IV, which is basically identical with the M127III but contains additionally the mechanical tach drive.

The M127III is the weaker 220SE engine with only 120 bhp (brake horse power; don't ask me for SAE numbers; 135 or so I believe) and has only the two-plunger fuel injection with the six individual nozzles in the intake manifold.

Instead the 230 SL engine has 82 mm (millimeter) bore instead of 80 mm (220 SE) and develops 150 bhp (170 hp SAE) and has an in-line 6-plunger fuel injection pump with direct fuel lines towards each cylinder/fuel injection nozzle, which themselves are located in the cylinder head (right side of the car/engine) injecting the fuel directly into the corresponding comubstion chamber thereby passing (and cooling) the inlet valves.
250 and 280 engines have basically the identical set up of the 230 engine.

The 220 SE engine can be used in either Pagoda; however, make sure to use the correct SL motor mounting arms from the SL engine. The SE motor mounting arms cannot be used. There was a discussion about this difference on the forum a while ago. Please use the "Search" function for this.
You have to live with the less performance of the SE engine then...

If I were you .... let it be.
Hunt for a decent used M127II engine or get yours overhauled; on the long run only the cars with the correct engine for the chassis are acepted by the today's Pagoda fans and aficionados. But basically it can be done and it is your car.

Achim
(ex M127III owner)

[Benz Dr.]

Just a small point of clairification.
The engines used for 113 cars are NOT directly fuel injected - they are port injection. The 220SE engines are manifold injection while only the 300SL and 300SC engines of the 1950's and early 60's were direct injection.
It is possible to bore out some 220SE engines to fit 230SL pistons but you need at least 8mm of cylinder wall thickness. Anything less than 7mm is a no go.