Author Topic: Crankshafts 250/280  (Read 2738 times)

jvcarrier

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Crankshafts 250/280
« on: March 15, 2013, 12:25:31 »
Hi
I am in the uk and restoring a 250sl. The crank has reached the end of its regrinding tollerance.
There is a 280sl short engine available (condition unknown) - is the crank from a 280sl interchangable with a 250sl  if so do I need to change rods as well?
Pistons will need to be made anyway so I have some flexibility there.
 Regards

John



Benz Dr.

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Re: Crankshafts 250/280
« Reply #1 on: March 15, 2013, 13:59:55 »
The rods are different but I believe the cranks are the same.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

w113dude

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Re: Crankshafts 250/280
« Reply #2 on: March 15, 2013, 14:05:09 »
I recently had both out side by side, one from a 250 and one from a 280, they looked identical but I did not use a micrometer to look through all the specs.

ja17

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Re: Crankshafts 250/280
« Reply #3 on: March 16, 2013, 19:48:52 »
Check the casting numbers on the crankshaft itself.  I believe that there are three different crankshafts for the 250 series. I see three completely differentmain  bearing sets supplied for the various 250 S, SE crankshafts. The 280 S, SE used only one crankshaft, however it did use two different main  bearing sets depending on the block style. None of the 280 series bearing sets are the same as the bearing sets for the 250 series.   The latest version 250 crankshaft could be the same as a 280 but be sure to check the width of the thrust bearing on main journal #3 also check all the oil hole locations. The casting number on the crankshaft is the best way to be sure.

You probably can find someone on this site who has a good used 250 series crankshaft as an alternative.  
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