The
Oldcorollas FAQ
An FAQ dealing with KE1x to KE7x Toyota Corollas
Supplement to http://groups.yahoo.com/groups/oldcorollas
There are two basic types of alternator used on K motors. They are
fully interchangeable, as long as you get the accompanying top and
bottom brackets.
The Denso manufactured unit is the japanese production alternator. It's
a 35A three-phase unit with an external regulator, quite limiting once
you start to add goodies that steal your ignition voltage (90/100
headlights, gauges, etc). The later Bosch alternator is a bit better,
it supplies 40A and has an internal regulator, so your engine bay looks
neater and you don't have to worry about wiring during a transplant. In
my experience, you usually find Denso alternators on early models
(KE1x, 2x, 3x) and Bosch ones on later models (KE5x, 7x) but this is
not always the case.
However, here's the beauty part. Bosch design all their alternators
with the same rear housing, just with different front housings to suit
the motor they are intended for. So you can buy yourself a 60A Ford
Falcon alternator, or an 80A VL Turbo alternator, and rebuild it with a
Bosch KE front housing and longer stator bolts, and whack it straight
onto your K motor. If you want to underdrive the alternator (say you're
bulding a big-rpm race motor, use a Mitsubishi Sigma front pulley)
The charge wire through the wiring loom is also quite small, at most it
could supply maybe 30A, it is reccomended that once you start upgrading
bits, disconnect the charge wire to the loom and run a thick wire from
the B pole of the alternator to the + of the battery. If you do this,
and have an alternator with an external regulator, don't forget to wire
the applicable regulator terminal back up to the B pole (look at a
wiring diagram) or your alternator will overcharge and your battery
could explode!