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Air to Turbo
06-13-2008, 04:41
Post: #4
Air to Turbo
Turbo Diesels are by nature very "Air Rich", in that respect they have very
different needs than a gas engine. Putting in 25% more air will yield nothing.
To get more power is simple, just add fuel. Different injectors {or timing on
computer controlled engines) is how you do it. Want economy? Reduce the fuel
input.
How fast you want to go? = How much fuel you want to burn?

Pete


-------------- Original message ----------------------
From: Pete Masterson
> While I worked at NASA Ames Research Center, I learned that "fluid
> dynamics" often applies very directly to air flow. So, observations
> about hydrodynamics very often directly applies.
>
> Air for combustion is best obtained from the coolest source. On my DD
> Series 60 (and I think the 8v92s) there is an "air charge cooler"
> that is used to cool the air after it passes through the turbocharger
> and before it goes into the combustion chamber. Cooling the air makes
> it denser. Compressing air makes it hotter.
>
> I've heard a fair amount of anecdotal reports of improved 3208
> performance by routing air intake to the front of the engine
> compartment, away from the behind the radiator. (Other FC owners with
> experience on this point would be far more help.) With a naturally
> aspirated front engine, a proper shape of the air inlet can result in
> "ram air" that gives a slight power boost. Ram air is much less of
> an issue with a turbo charger, but would have a minor positive impact.
>
> On the PT models, getting air from outside the engine compartment is
> ideal. I believe my coach has its combustion air inlet on the curb
> side above the large grate side access door. There is no scoop or
> other effort to increase air flow -- but my DD Series 60 shows no
> signs of lacking sufficient air.
>
> I've seen some sort of scoop at the top rear on some coaches with the
> 8v92. The problem is that if it faces forward (for the ram air
> effect) it tends to pick up undesirable debris. I think the main
> effort is to ensure that the engine has good access to fresh air from
> outside the engine compartment. Since the 8v92 (and 6v92) are all
> turbocharged, the ram air effect isn't especially important.
> Sufficient cross section and control of air-movement restrictions for
> what ever reason are important for ideal combustion.
>
> FWIW, I often wonder how the generator manages to work with its very
> restricted source of combustion air inside the sound compartment.
> (Indeed, my generator starts putting out tons of black smoke when the
> air cleaner is only a little dirty...)
>
> Pete Masterson
> '95 Blue Bird Wanderlodge WBDA 42
> El Sobrante CA
> aeonix1@...
>
>
>
> On Jun 13, 2008, at 7:15 AM, Gregory OConnor wrote:
>
> > Bill, like in our topic of door wind noise, turbulance of air causes
> > restriction of flow.Wind noise is a visual result of air
> > turbulance??? I removed a big acordian scoop from a tractor that
> > collected cleaner air from out of the hot engine compartment and
> > reduced the black smoke immediatly????? I learned that there was no
> > restriction in the pipe but my thinking is the air restricted its
> > self. you may notice corrigated 2 foot drain pipes stay cleaner than
> > smooth and bigger concrete pipe. the turbulant flow of water
> > restricts flow and uses the energy to work up otherwise settling
> > silt. I am sure air flow has major diffs than hydrodynamics??? But
> > turbulance causes heat and I wonder if 'just heated air' has
> > density lost??
> >
> > I am not sure 'hot air 'is that much less dence than cooler air. I
> > understood the advantage to be 'air just cooled'.?????
> >
> > Now DavidB and PeteM can add some math to convince you to look for
> > another project... Dig a pit and wait for the WhatsHisName's kids.
> > it's more fun than knocking beer cans off'a fence.
> >
> > GregoryO'Connor
> > 94ptRomolandCa
> >
> >
> > --- In WanderlodgeForum@yahoogroups.com, Wilhelmus Schreurs
> > wrote:
> >>
> >>
> >> When I purchased my coach, I noticed that the top of the air
> > cleaner (cage) and the ducting to the intake was removed. I believe
> > this was done as it is commonly believed to be known, that it does
> > not appear to get enough air from the outside.
> >> Some quick calculations show that the intake is 27in by 1 1/2
> > inches = 40 sq in.
> >> Intake to filter is 5 in round or equivalent to 20 square inches,
> > this should be adequate air flow, or maybe the intake to the filter
> > should be increased say to 7 inches. (38 square inches)
> >> Also does the turbo not suck the air in as well??
> >> What I am planning to do is to restore everything, as right now it
> > is getting the very hot air from around the engine, and I believe it
> > should be getting the colder air from outside?
> >> Any advice, pros and cons would be appreciated.
> >> Thanks in advance.
> >>
> >> Bill 84 FC 35 SB "$quanderlodge"
> >> Terrace, B.C. Canada
> >>
> >>
> >>
> > __________________________________________________________________
> >> Connect with friends from any web browser - no download required.
> > Try the new Yahoo! Canada Messenger for the Web BETA at
> > http://ca.messenger.yahoo.com/webmessengerpromo.php
> >>
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>





While I worked at NASA Ames Research Center, I learned that "fluid dynamics" often applies very directly to air flow. So, observations about hydrodynamics very often directly applies. 
Air for combustion is best obtained from the coolest source. On my DD Series 60 (and I think the 8v92s) there is an "air charge cooler" that is used to cool the air after it passes through the turbocharger and before it goes into the combustion chamber. Cooling the air makes it denser. Compressing air makes it hotter. 
I've heard a fair amount of anecdotal reports of improved 3208 performance by routing air intake to the front of the engine compartment, away from the behind the radiator. (Other FC owners with experience on this point would be far more help.) With a naturally aspirated front engine, a proper shape of the air inlet can result in "ram air" that gives a slight power boost.  Ram air is much less of an issue with a turbo charger, but would have a minor positive impact. 
On the PT models, getting air from outside the engine compartment is ideal. I believe my coach has its combustion air inlet on the curb side above the large grate side access door. There is no scoop or other effort to increase air flow -- but my DD Series 60 shows no signs of lacking sufficient air.
I've seen some sort of scoop at the top rear on some coaches with the 8v92. The problem is that if it faces forward (for the ram air effect) it tends to pick up undesirable debris. I think the main effort is to ensure that the engine has good access to fresh air from outside the engine compartment. Since the 8v92 (and 6v92) are all turbocharged, the ram air effect isn't especially important. Sufficient cross section and control of air-movement restrictions for what ever reason are important for ideal combustion.
FWIW, I often wonder how the generator manages to work with its very restricted source of combustion air inside the sound compartment. (Indeed, my generator starts putting out tons of black smoke when the air cleaner is only a little dirty...)
Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
"aeonix1@mac.com"


On Jun 13, 2008, at 7:15 AM, Gregory OConnor wrote:

Bill, like in our topic of door wind noise, turbulance of air causes 
restriction of flow.Wind  noise is a visual result  of air 
turbulance??? I removed a big acordian scoop from a tractor that 
collected cleaner air from out of the hot engine compartment and 
reduced the black smoke immediatly????? I learned that there was no 
restriction in the pipe but my thinking is the air restricted its 
self. you may notice corrigated 2 foot drain pipes stay cleaner than 
smooth and bigger concrete pipe. the turbulant flow of water 
restricts flow and uses the energy to work up otherwise settling 
silt.  I am sure air flow has major diffs than hydrodynamics??? But 
turbulance causes heat and I wonder if 'just heated air' has  
density lost??
 I am not sure 'hot air 'is that much less dence than cooler air. I 
understood the advantage to be  'air just cooled'.?????
Now DavidB and PeteM can add some math to convince you to look for 
another project... Dig a pit and wait for the WhatsHisName's kids. 
it's more fun than knocking beer cans off'a fence.
GregoryO'Connor
94ptRomolandCa
  --- In "WanderlodgeForum@yahoogroups.com", Wilhelmus Schreurs 
...> wrote:
When I purchased my coach, I noticed that the top of the air 
cleaner (cage) and the ducting to the intake was removed.  I believe 
this was done as it is commonly believed to be known, that it does 
not appear to get enough air from the outside.
Some quick calculations show that the intake is 27in by 1 1/2 
inches = 40 sq in.
Intake to filter is 5 in round or equivalent to 20 square inches, 
this should be adequate air flow, or maybe the intake to the filter 
should be increased say to 7 inches. (38 square inches)
Also does the turbo not suck the air in as well??
What I am planning to do is to restore everything, as right now it 
is getting the very hot air from around the engine, and I believe it 
should be getting the colder air from outside?
Any advice, pros and cons would be appreciated.
Thanks in advance.
Bill 84 FC 35 SB  "$quanderlodge"
Terrace, B.C.  Canada
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Messages In This Thread
Air to Turbo - Wilhelmus Schreurs - 06-12-2008, 18:39
Air to Turbo - Gregory OConnor - 06-13-2008, 02:15
Air to Turbo - Pete Masterson - 06-13-2008, 03:48
Air to Turbo - PM7088@... - 06-13-2008 04:41
Air to Turbo - Scott Forman - 06-13-2008, 04:57
Air to Turbo - Glenn Allen - 06-13-2008, 18:54
Air to Turbo - Gregory OConnor - 06-14-2008, 01:55
Air to Turbo - Glenn Allen - 06-14-2008, 08:05
Air to Turbo - Gregory OConnor - 06-14-2008, 16:51
Air to Turbo - Wilhelmus Schreurs - 06-15-2008, 04:53
Air to Turbo - Wilhelmus Schreurs - 06-23-2008, 09:07
Air to Turbo - David Brady - 06-23-2008, 09:26
Air to Turbo - michaelhohnstein - 06-24-2008, 05:08



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