Was hat das eine mit dem anderen zu tun?
lG
Bastian
PT u. ABH Zylinderbeschichtung - Dokumentiert?
77 Beiträge · 33.440 Aufrufe · gestartet
Ja,
das klingt verdammt stark nach AluSil. Ich werde das prüfen.
Danke!
Bastian
das klingt verdammt stark nach AluSil. Ich werde das prüfen.
Danke!
Bastian
Jetzt wird's prickelnd:
http://www.audiv8.com/forum/files/182559-Zylinder.jpg
Sieht irgendwie gleich aus... wie gesagt, ich möchte noch hören, was in der Liste zu dem Verfahren gesagt wird. Aber ich wette, dass es sich hier _nicht_ um NiKaSil handelt.
Bastian
http://www.audiv8.com/forum/files/182559-Zylinder.jpg
Sieht irgendwie gleich aus... wie gesagt, ich möchte noch hören, was in der Liste zu dem Verfahren gesagt wird. Aber ich wette, dass es sich hier _nicht_ um NiKaSil handelt.
Bastian
........die von Euch oben genannte Firma hat auch im Katalog AluSil stehen..............wäre schon interessant zu wissen.......finde ich klasse das dies hier mal nachgeforscht wird.............
na das war eine "deiner" Aussagen.... wenn überhitzt dann mehr Ölverbrauch... weisst du nicht mal mehr was du schreibst?? 
Nicht WÄHREND er überhitzt, sondern NACHDEM er einmal/mehrmals stark überhitzte.
Bastian
Bastian
So was neues:
Sehr geehrter Herr Freiberg,
lt. den uns vorliegenden Unterlagen wurden die Motorblöcke aus Alu-Silizium hergestellt.
Ob die Lauffläche herstellerseitig nochmals beschichtet wurde können wir leider nicht sagen.
Insofern bitte wir Sie, sich an den Hersteller zu wenden.
Sollten Kolben mit Eisenbeschichtung oder Zinnbeschichtung verbaut wurden sein ist allerdings davon auszugehen, dass die Laufflächen nicht nochmals beschichtet wurden.
Die Kolben bzw. Kolbenringe laufen in diesem Fall auf den durch das Honverfahren freigelegten Siliziumkristallen.
Kann Euch das weiterhelfen!?
Sehr geehrter Herr Freiberg,
lt. den uns vorliegenden Unterlagen wurden die Motorblöcke aus Alu-Silizium hergestellt.
Ob die Lauffläche herstellerseitig nochmals beschichtet wurde können wir leider nicht sagen.
Insofern bitte wir Sie, sich an den Hersteller zu wenden.
Sollten Kolben mit Eisenbeschichtung oder Zinnbeschichtung verbaut wurden sein ist allerdings davon auszugehen, dass die Laufflächen nicht nochmals beschichtet wurden.
Die Kolben bzw. Kolbenringe laufen in diesem Fall auf den durch das Honverfahren freigelegten Siliziumkristallen.
Kann Euch das weiterhelfen!?
Hi Frank,
ja, sehr sogar - es deckt sich mit dem, was zwischenzeitig wieder über die V8-Mailingliste an Infos reingekommen ist (ein wahrer Berg von).
Um nix zu verwechseln, poste ich mal, was rausgekommen ist. Englischkenntnisse Voraussetzung.
lG
Bastian
ja, sehr sogar - es deckt sich mit dem, was zwischenzeitig wieder über die V8-Mailingliste an Infos reingekommen ist (ein wahrer Berg von).
Um nix zu verwechseln, poste ich mal, was rausgekommen ist. Englischkenntnisse Voraussetzung.
lG
Bastian
> >Hi,
> >
> >finally I got some "official" information concerning the ABH:
> >
> >The internal product information for the introduction of the V8 4.2
> >(10/91) says:
> >
> >"The engine block is made of an aluminium alloy with 17% silicon
> >contingent. In a special etch process the hard silicium cores are
> >exposed, which form the piston contact surface. Usual piston liners are
> >therefore needless.
> >
> >The light alloy pistons have galvanically applied iron coatings with a
> >flimsy tin film on it. Benefit: Highest friction resistance."
> >
> >The press map of 12/1991 says the same thing.
> >
> >So, what is it?
> >
Alumsil - The piston coatings are identical to the Porsche and GM ( Vega) engine technologies of that era- that's why Audi used
similar techniques- it was well proven by the late '80's.
These engines need really GOOD quality rings to withstand the abrasive nature of the silicon that is left
in the bores. Also the break-in procedure is critical to seat the rings ( see the Porsche 928 shop manuals for one such procedure)
In the original designs (circa 1972-1980) iron coatings ( over alum pistons) was the preferred method to insure that the piston
skirts would also survive the rigors of the silicon bores.
One cause of high oil consumption in these engines can be due to poor rings and/or bad break-in procedures. Also heavy piston side loads
can really screw up the ring/bore surfaces.
Modern plasma coatings can also withstand the silicon bores but they are more costly than the iron coatings.
I've been racing and/or rebuilding alumsil engines for over 30 years ( ran 200 hp Vega and 450 hp 928 engines) so I'm more than a little
familiar with the technologies.
> >
> >finally I got some "official" information concerning the ABH:
> >
> >The internal product information for the introduction of the V8 4.2
> >(10/91) says:
> >
> >"The engine block is made of an aluminium alloy with 17% silicon
> >contingent. In a special etch process the hard silicium cores are
> >exposed, which form the piston contact surface. Usual piston liners are
> >therefore needless.
> >
> >The light alloy pistons have galvanically applied iron coatings with a
> >flimsy tin film on it. Benefit: Highest friction resistance."
> >
> >The press map of 12/1991 says the same thing.
> >
> >So, what is it?
> >
Alumsil - The piston coatings are identical to the Porsche and GM ( Vega) engine technologies of that era- that's why Audi used
similar techniques- it was well proven by the late '80's.
These engines need really GOOD quality rings to withstand the abrasive nature of the silicon that is left
in the bores. Also the break-in procedure is critical to seat the rings ( see the Porsche 928 shop manuals for one such procedure)
In the original designs (circa 1972-1980) iron coatings ( over alum pistons) was the preferred method to insure that the piston
skirts would also survive the rigors of the silicon bores.
One cause of high oil consumption in these engines can be due to poor rings and/or bad break-in procedures. Also heavy piston side loads
can really screw up the ring/bore surfaces.
Modern plasma coatings can also withstand the silicon bores but they are more costly than the iron coatings.
I've been racing and/or rebuilding alumsil engines for over 30 years ( ran 200 hp Vega and 450 hp 928 engines) so I'm more than a little
familiar with the technologies.
One of the MAJOR issues with the silicon/aluminum engines is that they ARE subject to cylinder scuffing especially in hi-load, low RPM
situations. GM saw this in the early Vega ( one of the first aluminum-silicon engine designs) as has Porsche in the 944/968 4 cylinder engines.
The V8's I've looked at have all had oil issues due to adverse/high side loads on the piston or oil contamination causing cylinder wall
damage.
Since I've helped rebuild a dozen or so Alumisil engines from multiple vendors that's what I've seen.
I still think the Nikisil rumors are just that- rumours.
Best regards-
--
//************************
Paul R. Cole:
'83 Urq Helios Blue ( SAR) #900335
'91 CQ Indigo Mettalic Blue, 165k miles- daily driver
'91 200 TQ 20V- new DD @ 263k miles
'91 200 TQ 20v- needs a few things but going strong @358k!!. Old cars-84x2 CGT, 89 200tq
'90,91 V8q- SAR
Bloomington,MN
pcolegrps@comcast.net # Powered by OS/2 Warp 4
//---------------------------------------
situations. GM saw this in the early Vega ( one of the first aluminum-silicon engine designs) as has Porsche in the 944/968 4 cylinder engines.
The V8's I've looked at have all had oil issues due to adverse/high side loads on the piston or oil contamination causing cylinder wall
damage.
Since I've helped rebuild a dozen or so Alumisil engines from multiple vendors that's what I've seen.
I still think the Nikisil rumors are just that- rumours.
Best regards-
--
//************************
Paul R. Cole:
'83 Urq Helios Blue ( SAR) #900335
'91 CQ Indigo Mettalic Blue, 165k miles- daily driver
'91 200 TQ 20V- new DD @ 263k miles
'91 200 TQ 20v- needs a few things but going strong @358k!!. Old cars-84x2 CGT, 89 200tq
'90,91 V8q- SAR
Bloomington,MN
pcolegrps@comcast.net # Powered by OS/2 Warp 4
//---------------------------------------
On Mon, 25 Aug 2008 19:09:32 +0200 (CEST), Bastian Preindl wrote:
> >4,2 cylinder bores are NiKaSil coated
AH- NO. at least for the 32valve engines I'm aware of.
The information from the folks that actually cast the blocks( Kolbenschmidt-Pierburg) indicates that ALL 32 valve
V8 castings were Alumisil ( alloy AlSi17Cu4Mg )
Links-
http://www.kspg-ag.de/index.php?fid=866&lang=3
Motor-Service home http://www.ms-motor-service.com/content_kataloge.asp?area=hauptmenue&site=katalog&cls=02
Catalog of KS technical manuals http://www.ms-motor-service.com/content2.asp?area=hauptmenue&site=technischebroschueren&cls=02
PDF link on reconditioning ALL alumisil KS blocks
http://www.ms-motor-service.com/download/prospekte/KS_50003804-02_WEB.pdf
news article here http://findarticles.com/p/articles/mi_m3012/is_10_183/ai_109505538
Basically if you have access to a machine shop that has the RIGHT equipment (Sunnen VC-20 for example) refinishing ( even after boring)
these engines isn't an issue.
I've rebuilt 2 Porsche 928 engines that use the same ( basically) material- no problems.
> >4,2 cylinder bores are NiKaSil coated
AH- NO. at least for the 32valve engines I'm aware of.
The information from the folks that actually cast the blocks( Kolbenschmidt-Pierburg) indicates that ALL 32 valve
V8 castings were Alumisil ( alloy AlSi17Cu4Mg )
Links-
http://www.kspg-ag.de/index.php?fid=866&lang=3
Motor-Service home http://www.ms-motor-service.com/content_kataloge.asp?area=hauptmenue&site=katalog&cls=02
Catalog of KS technical manuals http://www.ms-motor-service.com/content2.asp?area=hauptmenue&site=technischebroschueren&cls=02
PDF link on reconditioning ALL alumisil KS blocks
http://www.ms-motor-service.com/download/prospekte/KS_50003804-02_WEB.pdf
news article here http://findarticles.com/p/articles/mi_m3012/is_10_183/ai_109505538
Basically if you have access to a machine shop that has the RIGHT equipment (Sunnen VC-20 for example) refinishing ( even after boring)
these engines isn't an issue.
I've rebuilt 2 Porsche 928 engines that use the same ( basically) material- no problems.
Happy Labor Day weekend to all ..
Re-post of some info I posted on this subject the last time it came up
BMW info here: http://www.bmw4life.com/nikasil.htm
Some of the first patents on this technology (AKA: Alusil) were from work
done by GM/Reynolds with a Reynolds 390 Silicon alloy (etched).
Nikasil, was used as I recall, on early Porsche 911/917 race cars and
manufactured for them by; Mahle. Which was a thin-film coating type technology (As
BMW later used too).
Later 911/928 cars (and Ferrari) migrated to the Reynolds 390
silicon-and-aluminum alloy design, manufactured by 'KS'
Who manufactures many V-Aluminium blocks today including Audi.
KS Aluminium-Technologie AG (ATAG):
http://www.rheinmetall.com/index.php?fid=2046&lang=3
A more scholarly look at the technologies can be read here:
http://www.ncccoat.com/PDF/MercuryNCCSAEtechnicalpapers.pdf
Re-post of some info I posted on this subject the last time it came up
BMW info here: http://www.bmw4life.com/nikasil.htm
Some of the first patents on this technology (AKA: Alusil) were from work
done by GM/Reynolds with a Reynolds 390 Silicon alloy (etched).
Nikasil, was used as I recall, on early Porsche 911/917 race cars and
manufactured for them by; Mahle. Which was a thin-film coating type technology (As
BMW later used too).
Later 911/928 cars (and Ferrari) migrated to the Reynolds 390
silicon-and-aluminum alloy design, manufactured by 'KS'
Who manufactures many V-Aluminium blocks today including Audi.
KS Aluminium-Technologie AG (ATAG):
http://www.rheinmetall.com/index.php?fid=2046&lang=3
A more scholarly look at the technologies can be read here:
http://www.ncccoat.com/PDF/MercuryNCCSAEtechnicalpapers.pdf
Cheap rings . . . (no, not the four of them on the back of the car, THOSE sure aren't cheap!)
What may be happening is that since Audi knows the block is substantially more expensive than the
rings and the labor to replace them, they decided to use less wear-resistant rings instead of
super-duper never burns a drop of oil rings which would make the block wear out first.
One or the other will wear out - I prefer replacing rings to replacing engine blocks.
Same system is used on airplane engines - barrels are chromed internally, the rings wear, not the
cylinders, and it is FAR cheaper to replace pistons and rings than jugs. Airplane engines do burn
more oil than car engines, but that's because the clearances are looser to compensate for expansion
at wide open throttle and the vagaries of air cooling.
(Note that some aircraft cylinders are nitrided instead of chromed, a few are just plain steel with
nothing special done, these are the cheapest and don't last as long.)
We can give Audi the benefit of the doubt, and say they were planning for long-term ownership, or we
can also say it was obvious that the bean counters and team doorhandle spec'ed the rings. Your choice.
Best Regards,
Mike Arman
90V8Q
What may be happening is that since Audi knows the block is substantially more expensive than the
rings and the labor to replace them, they decided to use less wear-resistant rings instead of
super-duper never burns a drop of oil rings which would make the block wear out first.
One or the other will wear out - I prefer replacing rings to replacing engine blocks.
Same system is used on airplane engines - barrels are chromed internally, the rings wear, not the
cylinders, and it is FAR cheaper to replace pistons and rings than jugs. Airplane engines do burn
more oil than car engines, but that's because the clearances are looser to compensate for expansion
at wide open throttle and the vagaries of air cooling.
(Note that some aircraft cylinders are nitrided instead of chromed, a few are just plain steel with
nothing special done, these are the cheapest and don't last as long.)
We can give Audi the benefit of the doubt, and say they were planning for long-term ownership, or we
can also say it was obvious that the bean counters and team doorhandle spec'ed the rings. Your choice.
Best Regards,
Mike Arman
90V8Q
Yup. Also in my original press kit -- though even that was wrong wrt
engine displacement. ;-)
It is ALUSIL -- most definitely!
-Ingo Rautenberg
MIT Zwei PT Motoren und ein ABH Motor
engine displacement. ;-)
It is ALUSIL -- most definitely!
-Ingo Rautenberg
MIT Zwei PT Motoren und ein ABH Motor
You know, I never thought of the steel wool thing. In Classic and Exotic (hemmings) a couple of months ago they did the same for an old MG. That would work nicely int eh V8. I'll pull a set of vasve convers off the spare and see just how tough that would be.
Tony
----- Original Message -----
From: "urq" <urq@pacbell.net>
To: <v8@audifans.com>
Sent: Wednesday, August 27, 2008 9:48 PM
Subject: Re: [V8] Engine rebuild options
IMO we're not talking about the head design, rather the design of the oil vapor recovery system that sits in the valley between the heads. Years ago Scott and I compared notes on this ... What I found in my research of oil vapor recovery systems was that some manufacturers use brass or steel wool as a surface onto which the oil could collect ... where it would hopefully drain into the return galleries as Dr. Oeldrucker intended. What happens on acceleration is the oil sloshes up to the line where only fumes are intended to pass. One time I pulled the line at the front of the engine where the oil recovery line attaches to the intake manifold and saw signs of liquid oil. If someone wanted proof positive they could block the line at the intake manifold, feed the vapor recovery line to some sort of container ... and then go around and have some fun for a little while ... decelerating down long hills and then punching it at the bottom, or replicating any other sequence that in the past has caused a smokescreen a battleship captain would be proud of. I suspect the issue will be resolved ...
My theory as to why a rebuilt motor resolves the problem is that the tighter rings/valve seals reduce the amount of blow by gasses, which leads to less oil vapor to build up in the recovery system. I have a pad of brass wool which I was planning to drop into the recovery system on the PT I have sitting in the garage (that engine that came from #2).
Steve B
San José, CA (USA)
Tony
----- Original Message -----
From: "urq" <urq@pacbell.net>
To: <v8@audifans.com>
Sent: Wednesday, August 27, 2008 9:48 PM
Subject: Re: [V8] Engine rebuild options
IMO we're not talking about the head design, rather the design of the oil vapor recovery system that sits in the valley between the heads. Years ago Scott and I compared notes on this ... What I found in my research of oil vapor recovery systems was that some manufacturers use brass or steel wool as a surface onto which the oil could collect ... where it would hopefully drain into the return galleries as Dr. Oeldrucker intended. What happens on acceleration is the oil sloshes up to the line where only fumes are intended to pass. One time I pulled the line at the front of the engine where the oil recovery line attaches to the intake manifold and saw signs of liquid oil. If someone wanted proof positive they could block the line at the intake manifold, feed the vapor recovery line to some sort of container ... and then go around and have some fun for a little while ... decelerating down long hills and then punching it at the bottom, or replicating any other sequence that in the past has caused a smokescreen a battleship captain would be proud of. I suspect the issue will be resolved ...
My theory as to why a rebuilt motor resolves the problem is that the tighter rings/valve seals reduce the amount of blow by gasses, which leads to less oil vapor to build up in the recovery system. I have a pad of brass wool which I was planning to drop into the recovery system on the PT I have sitting in the garage (that engine that came from #2).
Steve B
San José, CA (USA)
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