Dan,

The DB2 is a little different animal than what we use on the DeltaHawk.
The DeltaHawk uses an independent, high pressure, plunger style pump
element for each cylinder. These run at significantly higher pressure
than the DB2 and also allow for redundancy in that the failure of a
single pump element will only take out a cylinder not the entire fuel
system. While in the DeltaHawk application there are some significant
advantages to the plunger style pump, what is commercially available in
this style of pump is not as fault tolerant to fuel lubrisity as the
DB2. However, although we currently use an off the shelf element, there
are some improvements that can be realized when volumes will allow us to
create a high pressure injection pump tailored to our specific
application. The long and short of things, with the current pump is
that while repriming once or twice isn't going to destroy the engine, it
isn't something that should become routine.

Dave Driscoll
DeltaHawk LLC

Dan Youngquist wrote:

On Sun, 28 Mar 2004, Dave Driscoll wrote:



This however is not a good practice as the high pressure pumps will be
operating without lubrication on the top side until the fuel is
reintroduced. The collective thoughts of the group are that you can
certainly get away with it a couple of times, but better be thinking
about inspecting the high pressure plungers after the 2nd full dry
restart.



Most of my diesel experience is with engines using Stanadyne DB2 injection
pumps. Stanadyne makes what they call an "Arctic kit" for this pump that
makes it insensitive to fuel lubricity by, if I understand correctly,
changing the material of some parts so any fuel, even gasoline, can be
used without damage to the injection pump. I've always wondered why they
don't make all the pumps that way to begin with; maybe there's a downside
I'm not aware of. Why doesn't DeltaHawk set up the injection pump that
way? Speaking strictly as a layman, it seems it would solve the run-dry
damage problem, as well as providing some emergency fuel flexibility.

-Dan