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Discussion Starter · #1 ·
I was looking at a BMW web page and they were discussing the bad effects of high sulfur gas and what it does to Nikasil blocks.
Anyone have this prob? Does anyone know what brands of gas have high sulfur content?
Thanks,Ken
 

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Ken, don't worry unless you have aluminum nikasil cylinders on your Harley.

JMS in TX
 

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http://65.38.172.84/forums/showthread.php?t=67435&highlight=nikasil

Internet = Information

Google this

The Boring Truth, Everybody's got ideas about treating cylinder bores; strong ideas

Wow. Little did we know what a fire-storm we'd start with a seemingly innocuous mention of aluminum engine cylinder-bore treatment alternatives in last September's materials issue (see WAW - Sept. '98, p.61).

There were plenty of letters and calls to point out we'd muffed our facts regarding the Nikasil treatment process - and we'll straighten out that matter directly. But several merely used that mistake as an excuse to expound their opinions - often vociferously - about what cylinder bore-coating strategies the industry really should be employing.

We don't need to be hit over the head to recognize controversy, so for the last few months we've talked to numerous supplier and OEM sources to develop an overview of the aluminum-engine cylinder bore-treatment options used throughout the industry - and to convey the remarkable polarization of opinion on the subject.

Most sources were delighted to discuss their convictions at great length - provided they wouldn't be named, highlighting the submerged political nature of this seemingly innocent subject. Suppliers don't want to rankle customers, OEM sources don't want to openly fuel already contentious philosophical battles within their powertrain groups.

All over cylinder-bore treatments, for gosh sakes.

First, Why? With the now-continual need to drive weight out of passenger vehicles, converting the heavy mass of engine blocks from their traditional cast iron to aluminum is a sure-fire method to deliver a major curb-weight cut; aluminum engine blocks can weigh 40% to 50% less than a comparable cast-iron block. And aluminum's excellent thermal conductivity often permits smaller-capacity cooling systems.

"I doubt there will be very many new passenger-car engine programs in the near future that don't specify an aluminum block," asserts one casting industry source. "And probably not too many (light)-truck engines, either."

But aluminum is an inherently "soft" metal, and cylinder bores of an engine block crafted purely from aluminum wouldn't long withstand the constant, grinding friction of pistons and piston rings scraping their way up and down the bore surface. Most aluminum engine blocks actually are fashioned from an aluminum-intensive alloy that contains other metals, primarily silicon. That helps, but that alone isn't nearly durable enough.

"It's pretty simple," says one OEM powertrain engineer. "You don't want aluminum-to-aluminum contact. You've got to have a bore with a high wear surface, and aluminum has poor wear characteristics."

Thus, the primary reason cylinder bores can't be aluminum. Once it's agreed the bore must be protected, the question is: "How?" Other factors such as cost, manufacturing consequences and performance requirements then must be squeezed into the equation. That's where the cylinder bore-treatment "factions" start to dig in their heels.

The Methods

Broadly, there are two ways to protect aluminum-engine cylinder bores: Either install iron liners or find a way to make the bore surfaces more wear-resistant, usually with some type of coating or treatment of the aluminum. Some approaches use rather exotic and elaborate processes to accomplish this feat.

Iron Liners: The utility infielder

Installing cast iron liners - or "sleeves" - equates to what might be called the industry "default" to answer the cylinder bore-treatment matter. Iron liners have numerous advantages:

n They are probably the most inexpensive method.

n They are delightfully durable.

n They are easily and inexpensively integrated into the manufacturing process.

Cheap and durable - the two words the industry holds most dear, right?

Well, there are problems with iron sleeves.

Sticking iron into your fancy new aluminum engine obviously negates some of what you're trying to do in the first place. Iron is heavy - that's why you switched to aluminum!

Perhaps more importantly, iron liners take up space. A common iron liner is roughly 3 mm thick. Multiply that by the number of cylinders you're dealing with and the engine starts to grow; there has to be a certain amount of block "webbing" between each cylinder to ensure structure, so the room that liners require can't always simply be chopped out of the space between each cylinder.

To now, that hasn't been a big deal in the U.S. One foreign castings supplier, who asks anonymity because he's wooing domestic business, explains: "In the U.S. you have the 'luxury' of displacement. Engines are large, so there is no particular need to use modern (bore treatment) methods. The car companies here always think first of cost and high volumes."

This source's emphasis on the word "modern" is inescapably scathing.

W. Gregory Wuest, vice-president-research and development at Sulzer-Metco, a New York company espousing cylinder-bore spray coating technology, agrees, noting that engines in Europe and Japan must be inherently smaller and more energy dense because fuel prices are so high. "In Japanese engines, for example, there's no room for a liner. They're driven (to other methods) by that factor."

Mr. Wuest notes that spray coatings usually can be applied in thicknesses of no more than 100 microns - one-thirtieth the space each 3 mm iron liner demands.

Iron liners typically are cast into the block as it's being formed. General Motors Corp. employs this method with its Premium V-6- and 8-cyl. OHC engines. Saturn simply presses in the liners. Ford Motor Co., for its Intech all-aluminum V-8s, heats the block and presses in the liners; when the block cools, it "shrinks" around the iron sleeves.

Iron and aluminum exhibit different thermal properties, though, which can be troublesome. And aluminum blocks and iron liners don't completely "bond," regardless of the joining method. That leaves gaps between the liner and the cylinder wall. The bonding and added-weight issues can be improved by using aluminum sleeves instead of cast iron - DaimlerChrysler AG likes aluminum sleeves for Chrysler's 4-cyl. and new V-6 engines - but aluminum liners are tough to cast directly into the block.

If liners are cast into the block - as in the GM method - scrappage becomes an issue. If the entire engine is built, only then to be discovered to be defective, the iron liners must be ripped out and are useless.

"We have some relatively high scrap costs," admits one powertrain engineer.

The Coatings: You pays your money, you takes your chances

This story was born when we first conveyed BMW AG's woes with Nikasil. So let's examine the competing cylinder-coating processes.

n Nikasil: An aluminum engine is dunked in an electrolytic "bath" of free-floating nickel, silicon and other junk. The electrolytic action causes these hardy substances to adhere to the aluminum surfaces.

"It does work very well in a lot of applications," admits one engineer philosophically behind iron liners. But Nikasil's main drawbacks are serious.

First, says Achim Sach, of VAW Motor GmbH, a part of the VAW Group aligned with Mexican casting giant Cifunsa SA, "Nobody wants to have nickel in the plants anymore." Also, as noted in September, high-sulfur fuels eat away at the coating, eventually rendering it useless. Result: ruined engine. And Nikasil has "throughput" issues: The block has to be labor-intensively "masked" before it takes a Nikasil bath, so that the particles cling only to the bore surfaces. And the block has to soak for more than an hour, claim some skeptical sources. Nikasil appears to be on the skids for these reasons. BMWhas abandoned the process. Jaguar Cars and Ferrari SpA still like it, though.

n Alusil: The engine block is fashioned from high-silicon content aluminum alloy. The block undergoes initial machining, then, similar to Nikasil, is dipped in an acidic bath that etches away the aluminum on the bore surfaces, exposing the durable-wearing silicon.

Again, however, there are considerable problems. Alusil blocks must be made in a slow, low-pressure process, says Mr. Sach, and the original alloy itself is more expensive. He believes Alusil is good for low-volume use where cost and manufacturing speed are not the priorities.

Alusil's cost might be bearable even for mainstream vehicles, but a foreign automaker engineer insists, "Throughput time is not acceptable for high-volume lines. We would never consider this process."

n Lokasil: Promoted largely by casting-kahuna Kolbenschimdt Pierburg AG, Lokasil is a "sacrificial" bore liner comprised of silicon fibers in a binding that, when inserted into the block mold, burns out the fibers, leaving the high-content silicon surface directly in the bores.

The Lokasil process is acutely effective. But it also is laborious - slow squeeze-casting is required - and expensive. Currently, Kolbenschmidt's sole customer for the process is Porsche AG.

n Finally, there is spray coating - thermal or plasma - and laser etching. Thermal and plasma spray coating, as a technique, has knocked around for some time; Sulzer Metco believes it eventually can be a prime force in the bore-coating industry. In one spray-coating method, a wire comprised of the material with which you'd like to coat the bore surface is heated and the "droplets" produced essentially are blown in a controlled fashion onto the bore surface.

Better yet, the bore coating, in powdered form, can be heated and blown into the cylinder, where it adheres to the bore surface. Ford, incidentally, owns the rights to the powdered materials themselves.

But Sulzer-Metco's Mr. Wuest is open about the process' drawbacks, particularly the high-velocity oxygen fuel (HVOF) method, which GM, he says, "has been working on for years, but they've never brought it to production." The problem with HVOL is the thermal loadings transferred to the block. One OEM engineer opposed to spray coating says, "That's one thing the spray coating promoters rarely talk about. You've got to bring the blocks up to a pretty high temperature. That's not easy; you've got to have a big investment to do all this, and pump heated coolant around and all that. There are large investments required to get going with that process."

But spray coating is attractive: no space-eating iron liners, the coating material selection is extensive - and it provides an iron-like durability and a "very natural" tribological surface.

But Mr. Wuest says two aspects currently mitigate against spray coating. "From what I've seen, it's cost - and the fact that it's a relatively new technology," he admits. There's plenty of industry dissension about the true cost of spray coating, but Mr. Wuest is frank with his figures: He reckons iron liners cost about $1.50 to $2 per bore; plasma coating probably ranges from $3 to $5 per bore.

Meanwhile, Nikasil runs from $5 to $10 per bore, the cost largely dependent on volume. Alusil and Lokasil cost even more.

VAW's Mr. Sach firmly believes laser etching - where an aluminum/silicon powder is fed into a laser that "etches" the material into the bore surface - is a promising technology. "We're very high on this for the future," he claims, particularly for near-term high-performance applications like direct-injection engines.

Finally, one domestic OEM engineer proposes a radical compromise: "My proposal for a new family of aluminum engines would have aluminum wet liners," the source says. "Wet" liners, around which coolant circulates, could be spray- or otherwise coated then simply dropped into the block - perhaps with the entire piston/con rod assembly already matched to the liner.

"I think people are afraid of wet liners because the design got a certain bad rap. Machining wet liners used to be a problem, but that was 20 years ago. And with separate aluminum liners, any type of treatment process could be more easily incorporated. Using wet liners isn't a lost art."

That might be true. As recently as 1994, GM was still employing wet liners - and for a high-profile engine, the 405-hp Corvette ZR-1 V-8.

Wet liners might have a bad "rap," but it's a reasonable suggestion. One that might bring some pacifism to this "boring" battle.
 

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You mean like these???

JMS said:
Ken, don't worry unless you have aluminum nikasil cylinders on your Harley.

JMS in TX
You mean like these??? :cool:

All Aluminum Axtell Cylinders
Check out our all aluminum cylinders. These cylinders are poured from high-grade aircraft aluminum and plated with a nickel, silicon carbide, composite coating for a diamond hard bore that will last for mile after mile and pass after pass. These cylinders are run by many of today's fastest racers in the AHDRA.
 

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Discussion Starter · #5 ·
Thanks Snowman,very interesting read but that still doesnt tell me if High sulfur fuels still present a problem with these cylinders
Ken
 

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My guess is that high sulfer fuel would still have the problem (I may be wrong). But, it doesn't matter in the US anyway. You can not buy high sulfer stateside. I understand much of europe is now the same way. I did a search for sulfer and EPA and found a lot of information.
I was worried too until I read up on it. Now I have the 98 nickel coated cylinders and love them.


Hope I helped,


Stan
 

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I ran my BMW K75s for 3 years with no problems , as stated hi sulfur gas isn't around anymore here because of the EPA
 

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Try Post #31

KGW said:
Thanks Snowman,very interesting read but that still doesnt tell me if High sulfur fuels still present a problem with these cylinders
Ken
From link previously posted - Post # 31 by HDWrench
"The Nikasil that is being used in the REV kits is not the same as the type used when BMW had the problem with the sulpher. They made cars for thier fuel, not ours, so they had a problem. The type used here in the use on all imports, as well as race engines will not have any issues with fuel type at all. The cylinders do match very closely there are a few small differences but again the cylinder is offering more cooling area. Only way to do that is more fin area, and the lack of the steel liner offers that much cooling of the cylinder. I have many remark from customers that have been watching fuel milage, oil temps all have said better milage, and lower oil temps. What more can you ask for?? And no I am not going to give a kit away sorry maybe Santa will put one in your stocking if you have been good, and have stayed away from the lizard juice"

Just my -2$en#e- but realistically -

a) I don't read about any problems with high sulphur fuels and motorcycles; what I do read about is things that happened in the 90's with BMW, as you started out with your first question.

b) Do you think they would keep on making these cylinders if they didn't last?

c) Have your searched for information on weather or not high sulphur fuel is even available in USA?

c) Now try asking about cam tensioner failures and you will get some replies :gun:
 

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Discussion Starter · #10 ·
Thanks,Snowman and I have all the info and experiance on chain shoes that I will ever need
Ken
 

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...Whew!!! Guess I can quit worrying about whether or not my cylinders are going to go to hell!!! Boy - it's been a good week already - first we learned 2618 alloy isn't going to melt or do something else that's horrible and now this!! Man-oh-man -- what a great start to the New Year!!!;)
 

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Tell 'ya a secret

FXDRYDR said:
...Whew!!! Guess I can quit worrying about whether or not my cylinders are going to go to hell!!! Boy - it's been a good week already - first we learned 2618 alloy isn't going to melt or do something else that's horrible and now this!! Man-oh-man -- what a great start to the New Year!!!;)
Nikasil coating has been around in Germany for at least 35 years on high revving 2 stroke engines. Way back then I had a Kreidler Florette 50 cc, 6.25 hp at 8500 rpm, torque not noticeable and I had a seized piston caused by tinkering too much with carbs and exhausts (some thing never change:duh?: ), piston was beyond repair, almost no visible damage to the bore surface, new piston and rings and off she went.
How about that for confidence?

EDIT: Added a pic I found a few minutes ago. Notice the horizontal cylinder.

 

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Vienna -

Thanks. Most prpobably don't realize how long it's been around or what caused some of the issues BMZ experienced re the gas. I think nikasil issues are :beatdh: !
 

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last year, the ford explorer family experienced non working fuel gauges. it was found that high sulphur fuel caused this.
typical fuel stops were determined to be walmart, brookshires chain store, diamond shamrock and others that resold no-name fuel. and yes this was in louisiana.
 

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Either in 2004 or 2005 around memorial day, a refiner in Houston Texas produced and sold high sulphur gasoline. This gasoline went to most big name oil companies along the Gulf Coast from Texas to Florida. Exxon and Diamond Shamrock were not reported as having bought the fuel. Texaco/Shell, Chevron etc did buy it. The high sulphur gasoline reportedly caused the corrosion of the silver contacts in the fuel tank gauge senders. The oil companies paid for the repairs. I closely watched as best I could on the internet whether any nikasil engines were affected. They may have been, but I never saw any reported as being affected, i.e., Jaguar, BMW etc.. I buy Diamond Shamrock or Exxon since then since I run nikasil. I make sure all my fuel goes on a charge card 'cause if they fry my cylinders I want to know whose fuel did it.

STB
 

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i was at the time selling fords. we got a memo concerning this problem which did in fact list diamond shamrock. may have been an isolated area thing???
 

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I don't doubt they all had it. They are a bit inbred or is that "cartel" word more appropriate. So much for Chevron's refining capacity since they had the high sulphur fuel too.

STB
 

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STB said:
Either in 2004 or 2005 around memorial day, a refiner in Houston Texas produced and sold high sulphur gasoline. This gasoline went to most big name oil companies along the Gulf Coast from Texas to Florida. Exxon and Diamond Shamrock were not reported as having bought the fuel. Texaco/Shell, Chevron etc did buy it. The high sulphur gasoline reportedly caused the corrosion of the silver contacts in the fuel tank gauge senders. The oil companies paid for the repairs. I closely watched as best I could on the internet whether any nikasil engines were affected. They may have been, but I never saw any reported as being affected, i.e., Jaguar, BMW etc.. I buy Diamond Shamrock or Exxon since then since I run nikasil. I make sure all my fuel goes on a charge card 'cause if they fry my cylinders I want to know whose fuel did it.

STB
Now that's interesting. I stay away from "no-name" brands - except if I'm in the boonies and there's nothing else. Usually use Sunoco, Mobil, Exxon, Shell... always premium. I'd have thought they produce gasoline to a spec and that's that. Wouldn't have thunk it! Darn good idea to purchase on a card for documentation. Thanks for the info.
 

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Before this post gets too crazy. I amnot a chemist, but I did ask that question to Brian at REV. Bottom line is that with not enough silca carbide the cylinder is soft add sulpher and it make a form of acid. The formula that they use is not effected by sulpher in fuel. SO rest easy my friends the REV cylinders are not going to be effected. :banana:
 

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good news

Hopefully Brian will post this on his website because I am sure many enthusiasts have not bought his cylinders for this very reason. Thanks for the good news 'cause I have tried to be as careful as I can when I buy fuel.

Seabrook
 
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