[Vwdiesel] Cetane and mileage

[James Hansen]

Doug.
With a lean running engine such as a diesel, you need to have an exhaust
temp gauge, then time away.  Remember the melt point of aluminum, and all
will be well.  If not, well, that will be all.
What you are actually referring to in your cetane statement of cetane
affecting timing would fall under flame front progression rather than timing
I think. Different fuels burn with differing quickness, but since the time
of injection start for differing fuels is the same all things being equal,
and when injection starts, burn starts. Fuel quality dramatically effects
burn speed/time.
 Timing by ear for performance on a diesel is a bad thing- can get real
expensive real quick.
I set mine at 1.00 mm usually. A hair higher if its an older lower
compression engine.
Incidentally, the pump stroke volume delivered varies with governor demand.
Performance tuning is a combination of max allowable fuel delivery, boost
aneroid setting, boost pressure, charge air temps, injector break pressure
and phasing,  and timing.
-James

> -----Original Message-----
> From: vwdiesel-bounces+jhsg=sasktel.net at vwfans.com
> [mailto:vwdiesel-bounces+jhsg=sasktel.net at vwfans.com]On Behalf Of
> HWY9FERGS at cs.com
> Sent: Monday, March 08, 2004 11:00 PM
> To: Vwdiesel at vwfans.com
> Subject: [Vwdiesel] Cetane and mileage
>
>
> New guy  here.  I wanted to correct my statement about varying
> the stroke of
> the pump when tuning.  It is actually just varying WHEN the pump
> stroke starts
> (as in timing, duh).  The stroke always stays the same.  Anyway,
> it seems to
> me when you are running a higher cetane fuel, then it's increased
> tendancy to
> ignite effectively advances the timing, and is better for efficiency.  So
> stands to reason if you are running crappy low cetane fuel,
> perhaps advancing the
> pump timing (a little beyond specs) might be called for. The
> question is-how
> much can you bump up the timing without risking damage and should
> it even be
> considered?? You could compare it to timing your gas engine by
> advancing until
> you hear the pinging and then backing off a tad. I know from
> experience my gas
> engines run stronger and get better mileage when I run the timing more
> advanced.  Anyone ever experiment with running with timing more
> advanced on their TD?
> Just some food for thought.  Later on, Doug
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel
> ---
> Incoming mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.593 / Virus Database: 376 - Release Date: 02/20/2004
>
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.593 / Virus Database: 376 - Release Date: 02/20/2004