Distributor RPM

Edwardatherton · Post by **Edwardatherton** » Tue Sep 04, 2007 11:39 am

I have just noticed in the manual that the centrifugal advance is quoted as...

0-1 degrees at 500 distributor RPM, and 18-20 degrees at 2250 distributor RPM.

Does this mean 1000 and 4500 crankshaft RPM?

If so this would make sense because 4500RPM is the max revs. I think this would mean the highest advance would be 53 degrees at the top right end of the map which doesn't seem unreasonable to me (I don't suppose it would ever use that bit of the map anyway!)

Oliver Sedlacek · Post by **Oliver Sedlacek** » Thu Sep 06, 2007 9:47 pm

Those numbers make sense if it's distributor RPM and spark advance in crank degrees. I don't understand where you're getting 53 degrees from, but distributors will usually lock the advance above about 4000 (crank) RPM.

aarc240 · Post by **aarc240** » Fri Sep 07, 2007 11:08 am

I believe the 53 degrees is 'all in' - ie intial plus centrifugal plus vacuum.
For a relatively low performance engine as in a Land Rover I would consider that pretty normal and yes, the top right box is where you would find it.
Be careful about those sort of advance figures on LPG though - a reasonable maximum for that fuel is around 36 degrees 'all in'.
Use the second map for LPG and sneak up on the mapping.