Author Topic: Piston interchangability  (Read 2589 times)

Col Webb

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Piston interchangability
« on: December 24, 2014, 17:00:07 »
Does anyone know if pistons are interchangeable. I have the 230 SL m 127 engine and just got shocked by the cost of new pistons. Mahle makes pistons for the 280 SL (m-130) and I think for the 250 SL (m - 129). The 280 pistons are less than 1/2 half the price of the 230 pistons. I know that the diameter is different for the piston/cylinder for each engine but I would assume that the machine shop could fix. I guess that a main issue is whether the 230 connecting rod would fit a 250/280 piston. I know the wrist pins are different sizes.  Alternatively, could you use 250 connecting rods on a 230 crank? I question using the 250 connecting rods for I understand that that engine has a longer stroke. Any thoughts would be appreciated. Yours Chuck

ja17

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Re: Piston interchangability
« Reply #1 on: December 25, 2014, 14:57:11 »
The pistons cannot be interchanged. The bore size is very different, the configuration of the rings is different,  the wrist pin diameter is different, the rods are different. The connecting rod bearings would not work with other rods.  Possibly oversize pistons from a M180 (230 finback sedan engine) with connecting rods, could be an easy adaption. I am not sure about the pricing on these pistons.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback