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#15
by
TDIMeister
on 16 May, 2004 10:25
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I have an HTTP/FTP server set-up on my personal machine, but uptime is not 100% as my computer (a desktop/portable hybrid) moves with me when I got on trips. I can do some wizardy with PDFs to make em smaller if you could send me raw scanned images as a single TIFF file, or a Postcript output, or even the finished PDF as you have it, in that order of preference.
I can have you upload the paper to my work FTP site and try to pare down the file size. If you're interested, send me a PM and I'll send you the log-in details.
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#16
by
fspGTD
on 16 May, 2004 13:01
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Wow, all sorts of various people up here trying to be helpful... thanks for the offers folks but for the time being, I have a solution! I was able to find some additional web storage space on another e-mail account and so I put the file up there. Feel free to download it directly. Before you click to it, be forewarned that it is a 20MB PDF file. IE: You might want to save this link directly to your hard drive rather than re-loading it every time you need to look at it! OK, the link is:
http://home.comcast.net/~jakeru/15dsae.pdfEnjoy!
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#17
by
fspGTD
on 16 May, 2004 13:06
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Wow, all sorts of various people up here trying to be helpful... THANKS for the gracious offers folks, but for the time being, I have found a solution!
I was able to find some additional web storage space on another e-mail account and so I put the file up there. Feel free to download it directly. Before you click to it, be forewarned that it is a 20MB PDF file. IE: You might want to save this link directly to your hard drive rather than re-loading it every time you need to look at it! OK, the link is:
http://home.comcast.net/~jakeru/15dsae.pdf
Enjoy!
This file will work for the time being - until I get to scanning in the individual pictures (which will be common JPEGS) and entering the text into HTML format. That way we can refer and embed specific, individual pictures when we post so everyone knows what we're talking about!
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#18
by
fspGTD
on 16 May, 2004 13:16
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Here is a quote I like from the 1.5D SAE paper:
"Only swirl chambers will permit rated engine speeds in excess of 83 U/sec of 5,000 rpm and a specific power output of 34 BHP per liter (25 kw)."
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#19
by
DieselsRcool
on 16 May, 2004 13:26
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Wow Jake! This paper is so cool. Thanks for taking the time to share this with all of us.
Larry
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#20
by
fspGTD
on 16 May, 2004 13:52
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You guys are most welcome. I am reading through it again myself! Everything I look through it, I learn something new it seems.
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#21
by
DVST8R
on 16 May, 2004 15:21
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Definatly worth the 1min download time
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#22
by
BlackTieTD
on 16 May, 2004 18:39
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aha! just in time to hit 'print' on the big office laser jet tomorrow AM with a coffee
thanks jake
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#23
by
VWRacer
on 16 May, 2004 19:18
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Thirty-one seconds to download...
Thanks Jake!
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#24
by
TDIMeister
on 16 May, 2004 22:21
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Wholy moly!! Author of the paper is "P. Hofbauer and K. Sator, Volkswagenwerk AG"! He must have been a walking diesel encyclopedia of knowledge.
Peter Hofbauer is Senior Technical Advisor at FEV Engine Technology in Auburn Hills, MI, where I worked between October 2000 until January, 2003. I didn't have a chance to work directly with him on any projects, but I was well aware of a number of his activities. Most of my time was spent on a project designing a new family of locomotive Diesel engines (4500 HP V12 and 6750 HP V16 :shock: ), although I did spend some time at Ford in Dearborn and also working on some EPA/DOE engine design projects.
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#25
by
BlackTieTD
on 17 May, 2004 09:13
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great read jake... i'm hardly into it, can't wait to read more.
TDImeister... are you the same guy who posted before/after pics of your silver passat on the vortex? if so.. tasteful, i like your car. i'll take 1 of those 6000hp jobbies!
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#26
by
VWRacer
on 17 May, 2004 14:43
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I'm still slowly reading my way through the paper, but am already struck by a few passages.
Here are a couple...
The compression ratios which permit attaining optimum fuel consumption in small swirl-chamber engines range between 16 and 18.
What do you think about that? Other texts on diesels I have remark that fuel efficiency goes up in NA diesels until the CR is about 26:1, when increasing mechanical stresses overcome further gains. I have to wonder about the effect of turbcharging.
and...
The 1.5l 50 BHP Diesel and the 1.6l 110 BHP spark ignition engine use the same internal engine components (crankshaft, pistons, conrods and bearings).
So why does it say that diesels are "necessarily" more expensive than their gassers?
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#27
by
BlackTieTD
on 17 May, 2004 15:05
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regarding your second point...
the 1.6L 110hp engine they refer to i believe is the herron head, early european GTI engine, that we never got this side of the water... it certainly isn't a regular old late-70s watercooled 8v, and i'm sure it would cost more to produce than an 80hp 1.8L GTI engine that we got for instance.
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#28
by
VWRacer
on 17 May, 2004 16:45
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Good points, BlackTieTD, but IIRC we did get a 1.6l GTI here in North America. Don't know if it was the same engine, though... :?
In any event, one of my diesel engine books slams VW for using gasser parts in their early diesel engines. Compared it to GM's failed effort employing the same economizing. Unfair, AFAIK, since the 1.6TD in particular has a great rep.
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#29
by
fspGTD
on 17 May, 2004 18:00
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I'll take a crack at these...
I'm still slowly reading my way through the paper, but am already struck by a few passages.
Here are a couple...
The compression ratios which permit attaining optimum fuel consumption in small swirl-chamber engines range between 16 and 18.
What do you think about that? Other texts on diesels I have remark that fuel efficiency goes up in NA diesels until the CR is about 26:1, when increasing mechanical stresses overcome further gains. I have to wonder about the effect of turbcharging.
I'd say I've got no reason to doubt the optimal CR's as presented for these motors, but I haven't read other sources that give conflicting information either. Have read some that supports it. I'd be surprised if the optimal CR were above 23:1, because the paper goes into a lot of discussion about "engineering tradeoff" of raising the CR to 23:1 to promote good cold starting and cold idling. I think the optimal CR depends on how much frictional losses increase as the CR increases, which is not the same for every engine. It would be increased on an IDI motor with all the combustion chamber surface area where more heat can be lost.
and...
The 1.5l 50 BHP Diesel and the 1.6l 110 BHP spark ignition engine use the same internal engine components (crankshaft, pistons, conrods and bearings).
So why does it say that diesels are "necessarily" more expensive than their gassers?
Where does it say that? The original 1.5 diesel engine block I think may be from the same casting at the 1.5l gasser, or might even be the same machined part number (not really clear on that), but I think may be different (they talk about reinforcements in certain areas for the diesel?), so I am not sure, would have to compare part numbers. The conrods are I think the same and I wouldn't be surprised if the bearings were as well. It does say that component tolerances are held smaller by selecting the ones most blueprinted for the diesel, also by using multiple head gasket thicknesses. This additional manufacturing complexity seems like it would add to the cost. Other sources of cost difference could be in the fuel injection components (injection pumps, etc) also there is the benefit of no spark system. The pistons are definitely different with a metal reinforcement inside the dieel version that's not in the gas, also a different shape on the surface. The paper goes into great length describing their development. Machining tolerances are higher with the diesel - they even matched pistons to bores according to "honing groups" to achieve the tight piston-wall clearance required in the Diesel. None of this is necessary in manufacturing the gas engine.