010 distributor ignition timing

[Travis71280]

Hi All,

Does anybody know what the ignition timing should be set to on a Bosch 010 distributor used on the later 1971 280SL? I just installed a Pertronix Ignitor II and was wondering if setting the timing at 38 BTDC degrees at 3,000 rpm with the vacuum hooked up still applies like the 051.

[Benz Dr.]

That's not the same unit that would be used in a late car but it does replace the 051. If you still have the constant vacuum throttle body it really won't work like it should. Changing to a vacuum retard throttle body will make it work right and yes, set to 38 degrees BTDC.
If you still have all of the vacuum switch over gear, and it still works, you should be using a 062 or 061 distributor.

[Travis71280]

Thanks, what does the vacuum retard throttle body look like? I think I have it as it has a vacuum port on the side of it on the same side as the throttle sensor where the ignition advance hooks up and a port on the opposite side for the vacuum throttle actuator. I don't think the distributor has ever been replaced, but the motor in the car must have been replaced sometime before 1986 because the motor serial number doesn't match what the car had from the factory.

[Benz Dr.]

Vacuum port is at the bottom of the throttle housing for VR and at the top for VA. If you have vacuum ports on each side then you ave the late constant vacuum housing.

[Travis71280]

Thanks, I'll take a look at it tonight. Correct me if I'm wrong, but are you saying that the 010 needs to see manifold vacuum and the later constant vacuum housing is just giving me ported vacuum instead?

[Benz Dr.]

The 010 needs manifold vacuum at idle. The late throttle housing gives constant manifold vacuum. So yes, I'd say you have it figured out.

[Travis71280]

I think I have the vacuum retard throttle body. Im assuming it is since the vacuum port is on the manifold side of the throttle plate.

[Benz Dr.]

Vacuum retard is on the bottom of the throttle body.

[kampala]

Travis,

from your photo it appears you have the stock throttle body for a USA 1970/1971 Pagoda - this throttle body provides vacuum all-the-time (continuous) and the vacuum to the distributor is turned on and off via  a two-way valve located near the coil area.  Just follow the vac lines - if your system is still stock.