"Charlie B." <cb1500@erols.com> responded to an
earlier question (which I missed) on coil voltage for
Crane ignition-equiped spitfires:
>I'm running a Crane XR700 and an after market 12v. coil, with the
>ballast resistor wire bypassed, on both my Spits. So far I've had no
>problems with my Crane units. The Crane unit doesn't care if the ballast
>is external or internal to the coil. Other units . . . I'm not so sure.
>The Crane instructions do indicate that if you're using a non-ballasted
>coil, external resistance must be used.
The real issue here is not the voltage applied to the coil,
but the input voltage applied to the Crane unit. My crane unit (on
1500 cc Midget; same engine) requires 6V, not 12 V, which is
not very clear from the instructions which serve to confuse the issue
with the language Charlie quotes above.
If the Crane unit is powered by the 12 V input, it will run fine--
for about 5 months, at least in my experience. My unit is now
driven at 6 V, by the use of the ballast resistor, and it has been
trouble-free for probably two years.
I suggest to anyone who has installed a Crane unit, and had questions
about the ballast resistance language, that you should reread the
ambiguous directions with my interpretations in mind, and if you
are running a crane unit at 12 V, rewire it for 6 V. If the Crane
unit is too hot to put your hand on it while operating, there is
something wrong, and you can expect a premature failure.
Best regards,
Ray
-------------------------------------
Ray W. James, P.E., Ph.D.
Texas Transportation Institute
Civil Engineering Department
Texas A&M University
College Station, TX 77843
Phone (409)845-7436; Fax (409)845-3410
E-mail: r-james@tamu.edu
Date: 1/4/98 Time: 10:57:04 AM
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