Vacuum Guage Timing (was 1275 timing advance)

[Greg MAHNEY <mahney@central.murdoch.edu.au>]

I seem to recall that the "How to be a Home Mechanic" course I went to
about 20 years ago recommended just using a vacuum guage to do your timing.

Basically, you set the idle to about 4000rpm and then turn the distributor
until you get the highest, steady reading.  I've given it a go and it seems
OK (but I wouldn't know if it is optimal).

Has anyone got a view (as if you haven't!) on this method?

Greg




>Set yor timing at speed not idle.  Most of the books call for 35 deg @
>4000 rpm, I find that 37-38 deg is about all you want to go for total
>advance at 4000 rpm.  As to what this is at idle depends on the
>distributor and points dwell it can vary a lot. My bug-i with 948cc and
>mechanical advance distributor is static timed at 12 deg BTDC with a
>points dwell of 60 deg to get 37 deg @4000rmp total advance.
>               Crash