Distributor advance limits

[RallyBob]

Here is a listing of US-spec distributor advance limits for 1.9 litre engines. One item worth noting is that automatic-equipped versions of these model year Opels had different advance rates (the advance occurred sooner), which was accomplished by using lighter tension springs on the mechanical advance. This was to help improve acceleration. Part numbers for the distributors for automatic-equipped cars were different than the same-year manual-equipped cars, but they were otherwise identical in operation. Except for 1975 Opels, all US-spec 1.9's had the static (idle) timing set to 0 degrees BTDC (before top dead center). Note that the engines had less and less total timing as the years progressed, in the interest of reducing exhaust emissions. Opel engines make the most power with a total timing figure of between 34-36 degrees.

1968 - 32-36.5 mechanical advance
19.5-22.5 vacuum advance
51.5-59 degrees total

1969 - 32-36 mechanical advance
11.5-14.5 vacuum
43.5-50.5 degrees total

1970 - 32-36 mechanical advance
11.5-14.5 vacuum
43.5-50.5 degrees total

1971 - 28-32 mechanical advance
7-10 vacuum
35-42 degrees total

1972 - 28-32 mechanical advance
7-10 vacuum
35-42 degrees total

1973 - 28-32 mechanical advance
1-5 vacuum
29-37 degrees total

1974 - 28-32 mechanical advance
1-3 vacuum
29-35 degrees total

1975 - 25 mechanical advance
5 degrees static timing
no vacuum advance unit
30 degrees total