| Author | Message | ||
| Jere Dunham (Questioner)
New member Username: Questioner Post Number: 16 Registered: 1-2003 |
Remember, BMW found the problem, repaired all the cars that had problems, spoke with the refiners to remove more of the excess sulfur and switched to Nikisil to prevent further problems. There has been no reoccurence of the problem since. BTW, BMW supplied to the owners of the cars affected a 100,000 mile warranty on the engine after the repair. Seems to me like they did their part. | ||
| Hans E. Hansen (4re_gt4)
Member Username: 4re_gt4 Post Number: 821 Registered: 4-2002 |
That's why I only eat Mexican Chili beans. | ||
| Jim E (Jimpo1)
Intermediate Member Username: Jimpo1 Post Number: 1213 Registered: 7-2001 |
No Martin, you just have to have your gas imported. | ||
| Martin - Cavallino Motors (Miami348ts)
Advanced Member Username: Miami348ts Post Number: 3692 Registered: 5-2001 |
...and you are talking a Ferrari is expensive to maintain? You have to fly the damn BMW back to Germany to fill up the tank to avoid engine malfunctions! | ||
| Jere Dunham (Questioner)
New member Username: Questioner Post Number: 15 Registered: 1-2003 |
At the time BMW had the problem with their cylinders, it was because they were using Galnickel (SP?),not Nikisil. The Galnickel had an adverse reaction to the excess sulfur that was in the crude oil being imported from South America. It was a localized problem, concentrating mostly along the Gulf Coast and upper West Coast as this is the entry point for the South American crude oil. The crude oil is better refined before shipping now and BMW switched to Nikisil afterward. There was no trouble found with the design of the engines themselves but plenty with the cylinder coating. The problem was not found during research and development of the engine in Germany because they get their crude from a different area. It took a number of years to finally determine what was causing this problem and many different theories were put out. | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 656 Registered: 11-2002 |
Porsche has used Nikasil and Alusil for 30 years at least, maybe longer on varying models of 911's & 930's (also, 4 cam Carreras used Nikasil ). For the high performance and racing variants the Nikasil is the preffered choice and in most instances the only choice. So the process has a very long, tried and true success rate. It is far from being a modern experiment. | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 307 Registered: 4-2002 |
In the 928 engine, Porsche used an aluminum with high silicon content. The cylinders were bored undersized, and then an acid was used to increase the size of the bore, leaving the silicon (dioxide?) above the aluminum walls. Silicon is much harder than the aluminum, increasing the wear of the bores (at least in concept). The Chevy Vega engine used a similar technique (quite unsuccessfully). | ||
| Greg Rodgers (Joechristmas)
Member Username: Joechristmas Post Number: 613 Registered: 3-2001 |
I have an 88' Esprit. It is a nice car. I like the 750ils too. I think they are built very well. | ||
| Dave Penhale (Dapper)
Member Username: Dapper Post Number: 498 Registered: 4-2002 |
Vague recollection of Porsche using something like this for the 928 bores, the opposite way around to more common approach, reverse reynolds principle(?) | ||
| Hubert Otlik (Hugh)
Member Username: Hugh Post Number: 445 Registered: 1-2002 |
omar- Nikasil is used to reduce the amount of wear and abuse on the cylinder walls from pistons scuffing the iron (or mostly Al, now) cylinder walls. Nikasil is nickel silicon carbide (carbides, by defenition are: binary compounds composed of carbon and a metal. There are various types of carbides; saline (group 1 & 2 elements and Al); metallic ( which are metallically conductive and have luster. Formed by d-block elements.); and metalloid (boron and silicon), the silicon carbide, however, only makes up for about 4% of the coating. The silicon carbide created adhesion spots that the oil can collect on, are responsible for increasing the longevity of the wearing surfaces on the cylinder walls. Increasing the lubrication adds to the longevity of the motor; i.e. service life, rebuild, oil consumption. Porsche has been using the Nikasil coating on this generation 911 TT motor w/ no adverse, reported, effects. The nickel is used because of it is comparitively ductile to stock sleeve. However, in recent times, auto maker have begun using FRM (Fiber reinforced material) cylinder sleeves which are composed of, in the case of the '97+ NSX's, 0.5-mm-thick layer with fibers of carbon and alumina (aluminum oxide, or Al2O2) in the aluminum alloy. The cylinder block's aluminum alloy is poured around cylinder cores composed of these two fibers. The cores absorb the molten aluminum during the casting. After casting, the cylinders are bored to a slightly smaller diameter than the cores, leaving a tough, wear resistant, composite cylinder wall integral with the block but reinforced by the fibers. The process allows larger bores within the same external block dimensions and bore spacing, and makes open-deck block construction possible. In the case of the NSX, they were able to bore out the same block casing (3.0 to 3.2), eliminate iron cylinder sleeves, and reduce the weight of the engine by ~ 6 pounds. Pretty cool, I think. Hope this helps, Hubert PS- The problems you're hearing about, I assume, with the E46 M3 engines is, by my account, due to incorrect crank clearances, rod strech, and an inability to properly lubricate the bottom end. The piston speeds, in that engine, approach those of an F1 engine, and to keep the motor together require that you have proper lubrication. BMW has changed the reccomended oil weight for those engines since their introduction; they came out using 10w-40, and are now up to 20w-60, someone correct me if I'm off here, which points to oil starvation, somewhere, in the engine. | ||
| Omar (Auraraptor)
Member Username: Auraraptor Post Number: 280 Registered: 9-2002 |
Umm Peter, I respectfully disagree. As the owner of 2 of them, in my experiance, I would say otherwhise. One thing, I can tell you I love self-tunning V12s  That said, any thoughts on why then? BTW Jake, You really love Lotuses(Loti?) dont you? Hope they treat you well. I was thinking of getting a 88, but was scared away  | ||
| Peter S�derlund /328 GTB -88 (Corsa)
Member Username: Corsa Post Number: 296 Registered: 4-2001 |
I think that's a BMW-problem. Everybody thinks that a BMW is a high quality product. It's not. Ciao Peter | ||
| jake diamond (Rampante)
New member Username: Rampante Post Number: 49 Registered: 4-2002 |
Lotus has used Nikasil liners since the 80's....no problems in that dept. , either. | ||
| Omar (Auraraptor)
Member Username: Auraraptor Post Number: 274 Registered: 9-2002 |
Interesting, Why did poor BMW have so many problems that f-car and p-car avoided? | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 651 Registered: 11-2002 |
Porsche used Nikasil in everything long before BMW and never had problems. But a Cylinder Leakage test is a VERY Wise Idea anyway. | ||
| Omar (Auraraptor)
Member Username: Auraraptor Post Number: 272 Registered: 9-2002 |
I was reading and have learned most modern f-cars are nickisil treated...ok whatever. But then remember this topic on roadfly...nickisil=bad. BMW had major problems with nickisil in M60 series engines (M60B30, M60B35 and M60B40 if I remember correct)..to the point they were replacing the engines free of charge to bmw owners if the over wear problem existed. The sulfer in US feul killed the nickil liineing by reaciting with it..and leakdown tests are performed to make sure that everything is still ok in the chambers. My thoughts are this, we all say in genneral a driven ferrari is better than a gargae queen..but the use of gas alone wears the lining away...so wouldn't higher mileage engines aldo be prone to failture as the bmw blocks? My thoughts are anyone considering buyng a f-car with over 35k miles MUST preform a leak down test to make sure everying is ok in the engine befere buying it. Am I right in my thoughts..or just a boy crying wolf? |