David Christman wrote:
>
> I have a few questions about some of the electrical
> components on spridgets:
>
> 1) What is the expected lifetime of a Lucas distributor?
Till just before you have to get somewhere important, or through the end
of driver's school, failing just before time to qualify for your first
road race.
> In the Vizard book he mentions that the bearings wear out
> quickly. Any experience with modifications?
Yes. Use a 45D4 if at all possible, in place of the 25D4 that's
(probably) in there now.
Why so? The 25D4 (used through the 1974 model year at least) has a ring
of pot-metal cast into the base, to which the pinch bolt applies
pressure when you tighten the distributor after adjusting the timing.
Over the intervening 20 or 30 years, these cast rings crack. In mild
cases the cracked rings make the timing jump all over the place; in
extreme cases the distributor can actually pop out of the engine block.
When it does this between Turn 2 and Turn 3 at Sears Point Raceway,
it'll make you think you've grenaded the engine (because unburned fuel
meets in the header collector and explodes just under your butt with a
huge KABOOM) and you'll have to walk all the way back to the pits to
tell your co-driver that he isn't going to get a turn after all. And
you'll wish you had a quick-release steering wheel so you could just
hand it to him, saying nothing.
The 45D4 distributor has a plate-shaped boss instead of a ring -- that
is, where the 25D4 has what looks like a 2mm long section of pipe
sticking out of it, the 45D4 has what looks like a 2mm long filled
circle of metal sticking out of it. MUCH sturdier.
You'll need different points, as the LT lead on the 45D4 is a "new and
improved" method. Mini Mania was selling them, they were used on many
years of Minis apparently (as well as MGBs in 1975 -- the last year
before going to electronic ignition). Or I suppose you could put in a
Pertronix; I haven't done that on any of my cars yet.
> 2) If one wanted to replace a generator with an alternator,
> is the 72-74 midget setup a good option? I have noticed that there
> has been some discussion of alternators from other cars being adapted.
Alternators have been greatly enhanced since the early Seventies; you
can get them in much smaller packages that have much better reliability,
with much lower weight and power consumption (not that this is too big a
deal, though).
The only problem I ever had with my '74 Midget's alternator was that the
built-in regulator went out in such a way that it started cranking out
18 volts (something about spending most of the day at 6000 RPM, on a run
down Highway 1, may have contributed to this...) It boiled the water
out of my battery, causing the car to quit on me 26 miles north of
Cambria, California.
I would undergo every piece of tribulation, stupidity, expense, injury,
humiliation, despair and degradation I ever experienced with all my
British (and other) cars, *all over again,* just to have that one day
with my orange Midget. That, bar none, was the single best day I've
ever spent with a car -- *including* having it quit and being towed to
Cambria and the rest.
I am, however, hoping to do much better with the yellow Midget I'm
getting in another couple of weeks...
> 3) Is the stock starting motor adequate for a 9.5:1 CR engine?
Yes, assuming the brushes and armature are in good shape and that you
have new, low-resistance wires to the starter. You shouldn't expect to
see compression-related problems on stock starters till you're up in the
11:1 range -- Miq, what CR was the red Spridget running that we used to
have to bump-start (till we broke the axle, anyway :-)?
> I have seen other starting motors adapted for spridgets.
Actually, here's a weird starter problem I experienced once, on
*another* brand of under-1300-cc sports car (Alfa GT Junior, but we all
know that "Marelli" is just the Italian word for "Lucas"):
Had the starter go out on me intermittently. Sometimes it just wouldn't
turn the car over at all, sometimes it worked slow, sometimes okay.
After doing The Stupid Thing (starting with the most expensive component
first -- the starter -- then the next-most expensive component -- the
battery), I finally went through the real troubleshooting drill (what
works, how far is the power getting, will the starter turn without load,
etc.) and discovered that the hot cable from the battery to the input
terminal of the starter was internally corroded.
To be specific: when I shorted the starter terminals under load, smoke
started coming out of the *cable*. Knowing what happens when you let
the smoke out of an electrical component, I replaced it.
So after a $165 starter and a $50 battery that still wouldn't start the
car, a $6 cable from Pep Boys got me back on the road again.
So... if you're going to put any additional strain on the starter, make
sure the cables to and from it are sound.
Oh, and you already know about making sure the engine ground is in good
shape so you don't run all your starting current through the throttle
cable, yes?
--Scott Fisher
|