M127 III motor (220se) with a 230sl head (127 010 4220)

[getsmart]

Hi all,

This question is for our engine experts

Would an M127 III motor (220se) with a 230sl head (127 010 4220) have had to have had a rebore (with 230sl pistons) to take that 230sl head ? What would be the expected compression per cylinder ?

My motor is this coniguration so I'm just curious what the power output is going to be. I bought my project in pieces so have yet to start the engine since its not in the car yet

Rgds all,

Joe
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Copied from an Achim post....

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. Cool

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. Sad
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. Wink

Achim

[ja17]

Considering that the 250-SE/SL head is an usable upgrade for a 230SL engine, I am fairly certain that the 250 series head with larger valves is usable on a 220SE engine. In fact, they use the same head gaskets.

[getsmart]

Thanks Joe, so its appearing like the 220se engine is probably at its original state and bore, Benz Dr replied me with this too below. One day I might remove the head and check the bore. I wonder if I will notice a HP difference between this and a 230sl engine

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"A 230SL engine is really only about 140 HP. Trying to modify a 220SE engine into a 230SL engine is fraught with difficult and uncertain purpose"

Dan