[Vwdiesel] "leaning out" diesel????????

[slatersfb at aol.com]

Well, after screwing around for the past 15 or so years, I finally put a dial indicator on Gina, 91 Jetta 1.6 N/A, and on Clean Phil, 81 pick up, 1.6 N/A just to see where timing ended up & you are on the money in your prediction.
1.1 mm for Gina and 1.0 for Phil.
But, yeah, we could all just stick a dial indicator in the pump & be done with it, like you say. The kick for me any ways is trying to figure out what is going on in there and why my 15 years of diddling got my cars timing where it did. Each of these discussions brings me better understanding of what goes on. I seem to seek out the associated headaches.
 
Bob in the Entire State
 
*************  
 
In fact, I would be really curious to know what the final numbers are for those
tuning by guess and by golly. I bet it is a tick either way of 1mm.   
 
-----Original Message-----
From: James Hansen <jhsg at sasktel.net>
To: vwdiesel at vwfans.com
Sent: Fri, 09 Dec 2005 01:01:30 -0600
Subject: RE: [Vwdiesel] "leaning out" diesel????????



I can tell he is real close to the --nitty gritty..-----Black Smoke
  ----is too rich ?

___________________________________-
Black smoke is overfueled.  Rich and lean is a term traditionally used to
describe an air-fuel mixture on either side of stoichiometric mix in a
gasoline engine.
Try using consistent terms that the rest of the world uses, and you will
confuse less people. Eschew obfuscation and newbies will be less
misconstrued.



RIGHT.   can we regulate that ?  --you bet , Apple Pie.  --the fueling
screw.---now can we
go too lean ? on a NA ?  yes you loose power.  ---so ?  we adjust for an
optimum ---right
? RIGHT. ( TUNING ).
Remember this is assuming that Fuel is injected at the right TIME.----I am
just getting
warmed up.

Lets say that pressure is 30 inches of mercury ?  OK ? so far --Ja ? gut.

Leave everything the way it is ---then use a supercharger to make it 60
inches of mercury
? --Ja ?    how's do you like them for Apples ?---all is the same ?  ----NO
way
Jose.. ---what improves ? ---combustion efficiency --that's what.
__________________________________

Superchargers draw power from the crankshaft, and to pump 60 inches mercury
column or roughly 30 pounds per square inch pressure you will suck back
significant crankshaft horsepower, combustion efficiency be damned.  IDI
Volks run at max 10psi, wastegate controlled turbocharger.
High boost pressures are solely to get more O2 in the chamber, so you can
stuff in more fuel and make more power.  Cummins run up to 45 psi...(
slightly modded that it) so they can burn more fuel to make 580 hp out of a
block that used to top out at 350.



---so what ?   ---well
less smoke more smileage ---you cant loose.--

____________________________

In a diesel engine, installing a brick beneath the gas pedal in the real
world will do the same thing as turning on the max fueling screw and
reducing the fueling until you can't see smoke. It's easier to undo when you
need to drive at speed also.

Remember, this is a diesel, you aren't tuning a gas engine- the fuel screw
adjust the load capacity of the engine.  Swirl, turbulence and many many
variables present on a gas engine are not at all present on a diesel to any
great extent (cam timing, overlap, duration etc...).  Almost all the air
gets stuffed through the great equalizer-  the dime sized hole  in the
precombustion chamber that negates swirl.  Correct timing and good injectors
have more to do with performance than anything else, and in a diesel,
performance translates into mileage.    Once you embark into the land of
computer controlled tdi's the game changes a bit, but for the idi diesels,
set the pump to 1mm, the original "performance setting"  and have at it.  In
fact, I would be really curious to know what the final numbers are for those
tuning by guess and by golly. I bet it is a tick either way of 1mm.  It
doesn't take too much advance past 1.2mm before your egt gets high, and
power suffers, so be careful with that.

This just doesn't have to be so complicated.  It's a pump setting using an
accurate ruler called a dial indicator.   It can't get much easier, and
certainly doesn't need to be turned into a big wizard's art thing..

I guess this means I'm not a pump gang member.
Oh well
-james

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