From: "Paul Dorsey" <dorpaul@negia.net>
> Although my freshly rebuilt TR4 engine turns over well with the spark plugs
> out (and builds up to 20psi after about 10 seconds of cranking), if you put
> the plugs in its quite a different story. In fact, with the plugs in it
> will only turn over 3-4 times. With jumper cables from my truck's battery
> togather with a freshly charged 'jump box' it was still too heavy a load to
> start my new engine.
Paul, almost certainly that means you are not getting a good enough connection
to the starter or to ground. This is a very common problem when you start
trying to use jumper cables without a good battery in the vehicle being jumped,
and is particularly a problem with the rather current-hungry Lucas starters.
Rather than trying to hook up more voltage, I would suggest that instead you
get some proper battery cables and connect them properly. The battery doesn't
have to be installed, you can even leave it sitting on the floor if the cables
are long enough, but get battery clamp connections to the battery and a good
bolted connection to both the starter solenoid and a convenient ground point on
the engine and I think you will find it will turn your engine over fine against
compression.
If not, it's time to start looking for a new or rebuilt starter. Slow spinning
(it should turn very fast with the plugs out) may also explain your rather low
oil pressure. And a bad starter brush or winding can cause exactly that
symptom.
> Tomorrow I was also planning on using another vehicle with more jumper
> cables. If this fails to be enough juice then I might hook up two of the
> batteries (red to black)(I forget if this is parallel or series) but it
> would yield 24volts. Since I've only got the starter and coil wired up,
> what would be the harm of doing this?
_Probably_ won't hurt anything, for short bursts. But if you actually get 24v
to the starter, you will be overloading it and taking a chance on burning it
up. Twice the voltage means 4 times the power and 4 times the heat ... and
they overheat fairly quickly anyway. Likewise the coil will be seeing 4 times
as much power and heat as it is designed for, and the points will be seeing
twice as much current.
Far better to solve the actual problem, in my opinion, than to make matters
worse by trying to work around it.
Randall
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|