View single post by Mark Rosenbaum
 Posted: 05-12-2006 10:41 pm
PM Quote Reply Full Topic
Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
Status: 
Offline
 There are two rotor types available, the inexpensive conventional ones and the expensive rev limiter ones.  You'll find the former available most everywhere, including Delta and the JHPS.  You should be able to order the latter from your local Lotus dealer or Lucas parts distributorship.

I've attached a photo of the correct rev limit rotor for your persual.  Operation is mechanical.  The curved silvery colored arc is in electrical contact with the distributor shaft, which is electrically grounded.  The central section is in electrical contact with the high voltage from the ignition coil.  The central part with the two screws is held in position by springs.  As engine speed increases, this part moves outward against the spring pressure until it makes contact with the raised part of the silvery ring, shorting out the high voltage.  This causes the engine to quit running and begin to slow down.  Eventually the engine is turning slowly enough that the spring forces the central section inward.  At this time the high voltage is no longer shorted out, and the engine begins to run again.

Note that all Lucas rev limiting rotors are marked with the distributor shaft speed at which they operate.  This means that if you want an engine limit speed of 7000 rpm you should use a rotor marked 3500 rpm.  Rotors with several other limit speeds are available

There are two ways to tell what's in your distributor: (a) pop the cap and take a look, or (b) rev the engine and note the speed at which it either quits running or blows up.  Needless to say, case (a) is preferable.  :^}

Attachment: Rotor 54424982 DRB108 3500rpm #2.jpg (Downloaded 148 times)