[Vwdiesel] Add just turbo to NA

[Tad]

Interesting discussion.  I'm surprised nobody has mentioned injection
timing with regards to EGTs.  At least in the TDI world, retarded
timing will significantly increase EGT.

On 4/1/12, pmdolan at sasktel.net <pmdolan at sasktel.net> wrote:
> There is more to it when considering EGTs and turbocharging:  The
> increased mass of air entering the combustion chamber COOLS the whole
> process, whereas adding fuel INCREASES temps.  Not easy to see in a
> car, but if you have a truck handy, run it up a big hill heavily loaded
> and watch the EGT at a constant speed in the highest gear you can use
> to sustain speed.  Then, drop one gear and watch the EGT drop like a
> brick as you maintain the same speed (i.e., use the same amount of
> energy & fuel).  It is both the engine RPM and turbo working in a more
> efficient part of its map that throw a LOT more air into the same fuel,
> resulting in dramatically LOWER EGTs for a "leaner" mixture.
>
> Maybe that will help some of us to appreciate while a dedicated diesel
> head is disgusted in so many ways by seeing black smoke coming out of a
> stack.
>
> Further comment:: the valves, pistons and heads on an NA really are NOT
> very robust.  That is why we have cracked cylinder heads, and why you
> really need oil cooling jets to prevent the pistons from melting down
> when the power gets much over 70HP or so.
>
> On Sun, 1 Apr 2012 08:43:17 -0700, "Andrew .Libby"
> <libbybapa at gmail.com> wrote:
> A "leaner" burn on a diesel does not increase EGTs.  That is gasser
>> thinking.  Increasing the fuel for a given amount of air increases EGTs in
>> the functional range of fueling for these engines.  Decreasing the fuel to
>> air decreases the temps (this includes increasing the air side of the
>> ratio).
>>
>>
>> On Sun, Apr 1, 2012 at 8:11 AM, Val Christian
>> <val at mongo.mongobird.com>wrote:
>>
>> >
>> > A "leaner" burn will raise the temps, but is unlikely to cause a
>> > problem,
>> > as the valves, cylinderhead and pistons tend to be fairly robust, and
>> > they are far from marginal in the NA engine.
>> >
>> >
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>
>
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