Don't like the adverts?  Click here to remove them

direct injection diesel / huge starter motor

G

Guest

Guest
Hi Folks,
My eye caught the e-mail from CB mentioning direct injection
and a huge starter motor.
Does that also imply that I for example shall be able to bumpstart
my LC3 D-4D 120KDJ ?, does the engine start on the heat generated from
the compression only, and thus ready to fire when the injection happens?
If a bump start is used, will that cause any problems with the catalytic
converter if the engine does not fire-up immediately?
Regards Jorgen KDJ120 UK
 
Jorgen

Apologies if you already know the below, but here is a brief explanation
of diesel engine starting.

Diesel engines are "compression ignition", meaning that the heat
generated by compressing the air in the cylinders is enough to ignite
the diesel when it it injected. You can feel this for yourself if you
pump up a bicycle tyre using a hand pump: the end will get hot, and if
you do it vigorously enough it can be too hot to touch - the mechanical
work of compressing the air is turned into heat. So diesels don't need,
and don't have, spark plugs.

Some diesel engines have glow plugs, which literally glow red hot due to
electric current, to help with starting when they are cold; but these
are usually "indirect injection" engines, in which there is a small
cavity above the cylinder where the fuel is injected. Typically they
glow for a few seconds before starting to warm things up, and turn off
automatically a few seconds after the engine has started.

"Direct injection" engines, in which the fuel is injected straight into
the cylinder, don't normally need glow plugs as the heating effect from
compressing the air is enough to start the engine. However it does mean
that direct injection engines need powerful starter motors, and the Euro
spec 80 series diesel has a huge 24 volt starter for this purpose -
hence my comment. (I don't know its exact rating, but it is around 2kW
which is about 3hp.)


I don't know anything about the D-4D engine other than that it is direct
injection, but if yours has a manual gearbox I should think it will
bump-start OK. When I had battery trouble I bump-started my 80 series
very easily in 2nd gear. If you have an auto box don't even think about
it!

Again I don't know about diesel catalysts, but so long as you don't
squirt masses of unburnt fuel down the exhaust I don't see that it will
be a problem. So as long as it bump-starts reasonably quickly it should
be fine.

Christopher Bell
________________________________
From: [Email address removed]
[mailto:[Email address removed]] On Behalf Of Jorgen Gronberg
Sent: 23 January 2006 22:07
To: [Email address removed]
Subject: [ELCO] direct injection diesel / huge starter motor
=09
=09
Hi Folks,

My eye caught the e-mail from CB mentioning direct injection
and a huge starter motor.

Does that also imply that I for example shall be able to
bumpstart
my LC3 D-4D 120KDJ ?, does the engine start on the heat
generated from
the compression only, and thus ready to fire when the injection
happens?

If a bump start is used, will that cause any problems with the
catalytic
converter if the engine does not fire-up immediately?

Regards Jorgen KDJ120 UK

____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses
 
Back
Top