1965 230SL was rebuilt once

[Koolmarca]

Update on my engine rebuild status....   after a bunch of crossed wires, my mechanic here in Berkeley is finally in contact with Mike at Metric Motors (they are in the LA area) and my engine will soon be on its way and hopefully I will have my baby again and then can get advice for getting her "makeup refreshed".

[Benz Dr.]

Forgot about the FI pump. 220SE block would not work either. For one reason, FI pump has the wrong drive ratio.

If someone, who is not that familiar with the hardware, looks into the engine bay and sees the intake manifold and the cylinder head, he may mistake the motor for all-aluminum alloy.

I'm not sure what you mean by '' drive ratio. ''  Could you explain that for us?

[MikeSimon]

I'm not sure what you mean by '' drive ratio. ''  Could you explain that for us?

The 6-plunger FI pump on the SL was driven at half engine speed as opposed to the 220SE which rotated at engine speed. Thus, it had a different "drive ratio"

[Benz Dr.]

Are you saying that the distributor drive gear is half the size of a regular drive gear? How would they get the ignition distributor to work and somehow have the IP run at twice that speed? It's been a few years since I rebuilt one of those engines but I don't remember seeing anything different in the chain case or drive gears. Kind of confused here.

[MikeSimon]

The distributor always rotates at half the engine speed, because you fire each cylinder only at every other turn. The Fuel Injection pump drive gear is the difference. The 220SE pump ran at engine speed, the 230SL and all later SLs do not. I have not looked at a 220SE FI pump, but I would assume the drive gear looks quite a bit different to that of an SL

[Benz Dr.]

I have to respectfully disagree here. The injection pump on the 220 runs from the same shaft as the distributor drive and is essentially the same as the 230SL. Since the cam gear and distributor drive gears are twice the size as the crank gear, both of those shafts turn at half crank speed. The IP is connected directly to the distributor drive gear shaft and so could only turn at the same speed.

The timing on a 220SE can be set at either TDC or BTC as it sprays into the intake manifold right at the parting surface of the cylinder head. The 220SE and the 230SL are more similar than they are different.

[MikeSimon]

Dan: You are the expert here, so I will not dispute that any further. The only thing is, the final speed of the FI pump is determined by the ratio between the shaft and the gear on the FI pump. As the 220 Pump does not have a separate piston for each cylinder, it will have to actuate more often than the 6-piston pump for the SL. I remember a write up at the introduction of the 230SL where the author referred to the difference in the FI pumps between the 127 and 127II engine being the drive speed. I may be able to find that.

[mbzse]

.../... I never heard back from the Mercedes factory in Stuttgart about whether they do engine rebuilds or swaps in any of their factories.../...

You can forget about the M-B factories... they of course produce the current, modern cars and cannot worry about 50 yr old stuff!
You should communicate with Mercedes Classic, they can help
https://www.mercedes-benz.com/en/mercedes-benz/classic/classic-service-parts/mercedes-benz-classic-world-wide/

[Benz Dr.]

Ah, I think I know the difference. The 230SL has one lobe per cylinder on the camshaft inside the IP. The 220SE has two lobes for each of two cylinders inside the IP. So, in effect, it sprays twice per cycle rather than running twice as fast.