M-130 engine differences?

[Raymond]

I am replacing the short-block in my very early 280. Are there any differences I should be concerned about if I get a short block from a late 280?  I will re-use my original cylinder head.

Ray
'68 280SL 4-spd Coupe

[Benz Dr.]

Not interchangeable.

Daniel G Caron

[Naj ✝︎]

Doc,
How can you tell an early block/crank from a late one?
naj

65 230SL
68 280SL

[ja17]

Hello Naj,
You can  probably find the breaking points for the change in the BBB somewhere as I recall. You would have to find the breking point for the late SL engine and the late sedan engine.
The easiest way is to refere to our "cylinder head chart" and identify the engine by the cylinder head number.

There are some external differences that can be noticed easily. The early 280 engines have the external "pod" on the right side of the cylinder head, in which  the temperature sensor and the engine coolant temperature sender is installed. The later engines does not have this "pod" both sender and sensor install directly into the head!

I will try to get back with some engine numbers later Raymond.

Joe Alexander
Blacklick, Ohio

[Naj ✝︎]

Thanks Joe,
I just wondered if there was a way of telling early block from late just by looking at them?
naj

65 230SL
68 280SL

[Cees Klumper]

I pondered this question Naj, and maybe there are external signs, but I can't think of any off-hand. However:

- if the engine you're looking at still has the head on, Joe's suggestion to look at the head (casting number and/or sender configuration will do the trick
- if the engine does not have the head on, I suppose you can tell what version it is from looking at the cylinder and coolant ports configuration, since it will be unique to one of the two different style heads

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Benz Dr.]

There are a number of differences mostly to do with modifications done on the late engine. The blocks look pretty much the same from the oustide but certain holes are either bigger, deeper or moved to a different location.
 The cylinder head is what's really diffent and can only be used on a late engine. Also, the camshaft and cam bearings are different - maybe the rockers as well ( not sure )
The whole engine was redesigned with different head bolts, cumbustion chambers, larger oil drain hole at the back of the block for top end oil, deeper holes for longer head bolts and I think they went to a 8mm screw to fix the IP flange in place ( was 6mm )
The heads are as described and the intake manifolds are different - one for 69/70 and a slightly different one for 71 ( at least 5 or 6 different ones used during production )
  The use of transistorized ignition along with vacuum retard switch gear for distributor timing became common place on most MB engines.
Even then they were starting to think about cleaner running engines and the environment.

Daniel G Caron

[Ben]

Didn't I read somewhere that the sump was different ??  I belive it is finned. Maybe that would be an easier way to identlify a block without the head present, maybe the mounting holes are different...............maybe not !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Benz Dr.]

The late oil pans have windage trays on them and the sub pan is a little bit deeper. This will allow the use of the late oil pump that has a pressure relief valve on it and a rubber flange around the bottom of the pump screen.
 The sub pan is identified buy ribs stamped into the bottom surface - it's what I used on the Rocket engine.

Daniel G Caron

[Raymond]

.

[George Davis]

Ray,

Engelen's book may have the best answer, but I don't have it handy right now.  However, my BBB, page 01-9, indicates that the cylinder head design went from the earlier "square" combustion chamber to the "oval" chamber at chassis number 013615.  The head and block got six additional water ports at the same time.

The block was further modified at chassis number 016450.  The BBB doesn't give corresponding engine numbers.

Hope that's somewhat useful.

George Davis
'69 280 SL Euro manual

[Raymond]

Great news! I have found a short block that should work for me.  Thank you everyone for your help.

While I am doing this, if there are photos for the tech manual that would be helpful, let me know.  I'd love to return the favor for all the great help I have gotten here.

Ray
'68 280SL 4-spd Coupe