If anyone is planning on attending the Blackhawk Classic vintage race this
weekend at Blackhawk Farms Raceway, Rockton, IL...stop by an say hi. Look for
a red mini #42, parked near some teutonic bathtubs. BTW, they are supposed to
have 32 vintage aircraft at the meet plus Stirling Moss is the GOH.
jim
jfuerstenberg@dcmdc.dla.mil or xgg2356@dcmdc.dla.mil
"It has been said that motor racing shares in common with sex the distinction
of being of the most popular, most maligned and least understood of human
activities.
Charles Beaumont and William F. Nolan from "Omnibus of Speed"
From rwg1@postoffice.mail.cornell.edu Tue Sep 11 11:40:22 2001
From: (Roger Garnett) rwg1@postoffice.mail.cornell.edu
To: ahrendt@cg-atla.agfa.com (Dave Ahrendt),
Date: 17 Jun 93 11:25:55
Subject: Re: TC Charging Problems
Dave, who's net connection seems fixed at least, sez:
> As long as I've owned my 46 MG-TC I've had a small problem with the
> charging system; normally everything works fine until the headlamps
> are turned on. With the lights on I run at a discharge of about 7 amps.
Isn't that how it's supposed to work? Couldn't you fit a modern
60 Amp alternator? (Sorry about that)
> I reset the regulator to spec. It was set to approx. 13.5 volts
> at around 70 degrees. This was reset to 15.6 volts ...
> with the lamps off I them turned them on. As the book mentioned as norm
> the amp meter showed a discharge for a few miles and then started
> showing a charge of couple amps. Great! Except that the ignition started
> to stumble only under load. Just a small miss but bad enough. Turn
> lamps off..miss goes away.
Scott F. has responded with some comments about freshening the dynamo,
but, showing his debility in things electric, has neglected to address
the actual problem, misfiring when those Lucas "King of the Road" lamps
are fired up.
OK, I see 2 possible sources of the trouble: electrical or mechanical,
or a combination thereof.
First order of business, is to check if you have somehow angered the
creator, Lucas, by tampering with the powers that be, as it were. Make an
offering of burnt wires at midnight on the upcomming solistice, then make
sure of the quality of all connections- battery, engine & battery
ground, coil, distributer, etc. Check the contacts in the cut-out.
(Part of the archaic regulation system, for those unfamiliar with
the system). It's possible that with the headlamps on, the increased
current draw is creating an increased voltage drop accross a marginal
connect, allowing reduced voltage at the coil. Test for this by
attaching a voltmeter to the hot side of the coil, and monitor the
voltage under operating and misfiring conditions.
Resistive connections can be traced by checking the voltage along
parts of a circuit, (with a low voltage setting on the meter), under
both no-load, and maximum load conditions. Under higher load (more
current), the voltage accross such a connection will increase, robbing
desired voltage from the component(s) that should get it. A drop of more
than 0.5 to 1 volt between battery and the lights or starter should
be investegated.
ie: between battery ground & engine, or hot & starter, while starting, or
between hot & the lights in this case. If you get an increased voltage
reading under load, you can then check smaller and smaller portions of the
circuit until you discover where the problem lies. You may have corrosion
on the fuse contacts on the cut-out, in the wiring at the ignition
switch, or elsewhere under the facia, or a a flakey fuse itself, .
A second possibility, is increased load on the engine has pushed it
towards it's limit. By increasing the output of the dynamo, you have
increased the engine power needed to drive it, and possibly disclosed
a marginal ignition system or something.
Either way, also suspect your points condition & gap, the condensor, coil,
distributer, coil, wires, and plugs.
Or maybe your light are just too bright now...
________
/___ _ \ Roger Garnett (Roger-Garnett@cornell.edu)
/| || \ \ Agricultural Economics | "The South Lansing Centre
| |___|| _ | 3 Warren Hall | For Wayward Sports Cars"
| | \ | | | Cornell University | (Lansing, NY)
\| \ |__/ / Ithaca, N.Y. 14853-7801 | (607) 533-7735
\________/ (607) 255-2522 | Safety Fast!
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