Hey Russ, I can probably hit the 42 degrees at 3000 RPM's right now without making any adjustments, except moving the vacuum line.
As it stands the vacuum is always on and is currently on the retard side of the distritubutor. It is set to 800 RPM 4 ATDC as stated by the book & plate on frame. If I remove the vacuum the timing moves up to about 10 BTDC but is cyling at about 1200 RPM (going from memory right now. might be alot higher) I'm sure if I move the vacuum to the advance port it will be in the 42 degree range and IDELING at 3000 RPM. So my question is where do I set my idle speed? is it 800 RPM 8 BTDC? or do I attach the vaccum to advance, and bring the RPMs down with the idle screw on the carbs? If so down to 800? 1000? ... Do I lock down the distributor as is or do I still need to fiddle with it? Thanks George -------------- Original message -------------- > Well, I dug out my W114 technical data manual -- it says timing should > be 42 to 50 degrees at 3000 rpm with vacuum advance operating (funny -- > only 31-39 degrees at that RPM for the '71). I'd set the engine at speed > and see if the timing at idle sorts itself out. > > The TDM also says 8 degrees BTDC at starter speed without vacuum as an > "installation value." > > I also have a British aftermarket manual by Intereurope that specifies > TDC at 800 rpm with vacuum diaphragm disconnected. Also, 19 to 28 > degrees at 1500 rpm, 29-35 degrees at 3000, both with vacuum > disconnected. FWIW. The manual covers all W114s for all model years, so > I take its technical data with a grain of salt. > > As you can see by the above numbers, specs are pretty broad. I think > you can get the spark timing close just by listening to the engine. If > it idles smoothly and doesn't ping under load, I'd declare it to be at spec. > > Russ >
