I'm having problems with the starter motor on the old Rover. It's a fairly
recent recon unit - but has had a fair amount of abuse since I've fitted
an after market engine management system which of course produced starting
problems until tuned. And even although it's running well now the injector
pulses at cranking are set separately so rather hit or miss to adjust for
a very cold start. As the O2 sensor can't help with telling you what the
mixture is 'till it's running...

I've stuck my DC clamp meter (not the most accurate of devices) and
looked at the cranking current on a cold day. It's saying 550 amps - close
to the battery max - and it's turning over slower than I remember. So I'm
guessing at a shorted turn somewhere through overheating. Have had this
before.

Many Jap cars use a Denso starter which uses a smaller but faster motor
and reduction gearing. Said to use a lot less current and produce more
torque. And I can buy one with a specially made mounting for my engine.
For more than an exchange Lucas one - but not so much as to be out of the
question.

Seems to me a win win solution as it's much lighter as well. And of
course the lower current will give more volts to the ignition which might
help too. And if it should fail, I can get a secondhand motor only and fit
that to the adaptor plate for much less than the original cost - I'm told
they don't fail often so are cheap secondhand.

Any advice?

--
*Many people quit looking for work when they find a job *

Dave Plowman London SW
To e-mail, change noise into sound.

On 29 Jan, 11:10, "Dave Plowman (News)" wrote:

Any advice?

Get the mini motor (I had one on my Rangie). They work, they're often
a hell of a lot easier to fit to a big '80s lump as starters of that
period had grown huge and unwieldy. Just saving an hour's spanner work
can make it worthwhile (Volvo 960!)

Land Rover may carry them as cheap spares on a straight exhange. Many
of these old motors aren't refurbed for exchange any more, they give
you a geared mini style instead. Work enquiring, if you have a
friendly spares duffer.

In an earlier contribution to this discussion,
Dave Plowman (News) wrote:


Many Jap cars use a Denso starter which uses a smaller but faster
motor and reduction gearing. Said to use a lot less current and
produce more torque. And I can buy one with a specially made mounting
for my engine. For more than an exchange Lucas one - but not so much
as to be out of the question.


I don't understand that - it appears to defy the laws of physics! So the
motor itself runs at higher speed and lower torque - working through
reduction gearing - but the engine needs a certain amount of *power* to
crank it - based on the product of cranking torque and cranking speed. The
starter motor has to produce that power , so - unless it's dramatically more
efficient - it's wattage will be the same as the original Lucas motor. Since
watts = volts x amps, and you can't do much about the voltage, then surely
the current is going to be the same?
--
Cheers,
Roger
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In article ,
Roger Mills wrote:
Many Jap cars use a Denso starter which uses a smaller but faster
motor and reduction gearing. Said to use a lot less current and
produce more torque. And I can buy one with a specially made mounting
for my engine. For more than an exchange Lucas one - but not so much
as to be out of the question.


I don't understand that - it appears to defy the laws of physics! So the
motor itself runs at higher speed and lower torque - working through
reduction gearing - but the engine needs a certain amount of *power* to
crank it - based on the product of cranking torque and cranking speed.
The starter motor has to produce that power , so - unless it's
dramatically more efficient - it's wattage will be the same as the
original Lucas motor. Since watts = volts x amps, and you can't do much
about the voltage, then surely the current is going to be the same?

I *think* it's because a series wound motor isn't very efficient at stall
or close to that. They are very much better at their natural quite high
speeds. I've been told the Denso has a permanent magnet motor but can't
confirm this. Certainly old car wiper motors etc used to be series wound,
but changed to permanent magnet when better ones became more affordable.

--
*Plagiarism saves time *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Huge wrote:
On 2010-01-29, Dave Plowman (News) wrote:

Any advice?

I had a Bosch Heavy Duty starter motor fitted to my RV8 powered TVR
because of slow cranking problems, especially when hot, about 4 years
ago and it's been fine ever since.

I *think* that's what later Rangies etc than my engine use - certainly a
neighbour's one whizzes round compared to mine. But I've been told they
don't make one which fits the SD1 - the solenoid is in a different place,
and would foul the exhaust.

--
*Experience is something you don't get until just after you need it.*

Dave Plowman London SW
To e-mail, change noise into sound.

In article
,
Andy Dingley wrote:
Any advice?

Get the mini motor (I had one on my Rangie). They work, they're often
a hell of a lot easier to fit to a big '80s lump as starters of that
period had grown huge and unwieldy. Just saving an hour's spanner work
can make it worthwhile (Volvo 960!)

Yes - it's not an easy job on the SD1 either. So just being so much
lighter will help.

Land Rover may carry them as cheap spares on a straight exhange. Many
of these old motors aren't refurbed for exchange any more, they give
you a geared mini style instead. Work enquiring, if you have a
friendly spares duffer.

Sadly the SD1 uses a different design - the solenoid is in a different
place to clear the exhaust.

--
*Two wrongs are only the beginning *

Dave Plowman London SW
To e-mail, change noise into sound.

On 29 Jan, 11:40, "Roger Mills" wrote:

unless it's dramatically more efficient

It is. Different technology, with much better power/volume. However
it's not a high-torque technology, so gearing it makes sense.

Starter motors were geared in the 1950s, for starting big diesels.
Electric starter motors have always been able to run much faster than
the engines they were starting, so this was always a practical option.
It becomes a sensible option when the torque required starts to exceed
the direct torque of a motor with adequate power. So for crude low-
power motors gearing was only sensible for huge engines (obviously
gearing has an extra cost), but the better the motor tech, the smaller
the break-even point becomes.

A modern pod-car (like our Honda Jizz) is full of tiny geared motors
running seemingly huge output torques. I blame the cordless drill
makers.

On Fri, 29 Jan 2010 11:10:36 +0000, Dave Plowman (News) wrote:

I'm having problems with the starter motor on the old Rover. It's a fairly
recent recon unit - but has had a fair amount of abuse since

Hmm, I dismantled our truck one last year - the bearings had all gone
dry (the exhaust runs right next to it) and a seal had failed such that it
was slowy filling up with crud. It was much better afterwards :-)

I've stuck my DC clamp meter (not the most accurate of devices) and
looked at the cranking current on a cold day. It's saying 550 amps -
close to the battery max - and it's turning over slower than I remember.
So I'm guessing at a shorted turn somewhere through overheating. Have
had this before.

Are you certain it's not the battery or wiring issue? Any minor problems
can really mess with starting even if there are no signs of trouble when
things are running. I realise you've probably looked into it already, but
it doesn't hurt to ask - changing the starter is expensive faff if it
turns out to not solve the problem (or mask the real one)

cheers

Jules

On Fri, 29 Jan 2010 05:03:39 -0800, Andy Dingley wrote:
Starter motors were geared in the 1950s, for starting big diesels.

Bah, real engines use coffman starters or compressed air ;-)

In article . com,
Jules wrote:
I've stuck my DC clamp meter (not the most accurate of devices) and
looked at the cranking current on a cold day. It's saying 550 amps -
close to the battery max - and it's turning over slower than I
remember. So I'm guessing at a shorted turn somewhere through
overheating. Have had this before.

Are you certain it's not the battery or wiring issue? Any minor problems
can really mess with starting even if there are no signs of trouble when
things are running. I realise you've probably looked into it already, but
it doesn't hurt to ask - changing the starter is expensive faff if it
turns out to not solve the problem (or mask the real one)

Yes - I've cleaned and checked all the connections including the grounds.
The high current suggests a shorted turn somewhere in the motor due to
overheating. Remember we're talking Lucas here. ;-)

--
*I have plenty of talent and vision. I just don't care.

Dave Plowman London SW
To e-mail, change noise into sound.

Jules wrote:

Bah, real engines use coffman starters or compressed air ;-)



Real engines have maximum torque at zero revs, and don't need starters :P

Andy

"Dave Plowman (News)" gurgled happily, sounding
much like they were saying:

Many Jap cars use a Denso starter which uses a smaller but faster motor
and reduction gearing. Said to use a lot less current and produce more
torque. And I can buy one with a specially made mounting for my engine.
For more than an exchange Lucas one - but not so much as to be out of
the question.

A few years ago, I had a replacement starter on the old CX - and it was a
reduction gear type. It was astonishing how much more quickly it spun it
over. No probs with it before I sold the car.