Löysin mielenkiintoisen tekstin mailmalta.
Sillä taitaa tosiaan hieman olla merkitystä mistä tiivisteet ostaa.
Toki Beisan haluaa omiansa mainostaa, mutta kannattaa lukea.
You need to be careful of what seals material you are getting. There are many variations of Teflon and to some extent Viton.
Teflon isn't usually used in it's virgin (white) form because it's susceptible to wear and deformation. So normally fillers are added to improve this. Choosing the correct type and grade of the filler is very important. In this vanos application BMW chose a very high grade carbon as the filler. This is correct for several reasons. The vanos has soft non-anodized aluminum cylinder walls and the engine oil pressure is very low, 7.5-60 PSI, compared to the normal hydraulic applications 1,500 PSI. So you need a material that doesn't eat the cylinder walls as the Teflon slides against it, and that allows low enough friction to provide good performance (speed). Graphite would not damage the cylinder walls and has very low friction, but it is fairly susceptible to wear and wouldn't last long. Bronze and glass-moly are too harsh and would damage the cylinder walls and provide poor performance.
When I (Beisan) first looked into this I connected with the largest seals company in the world. They recommended a turquoise Teflon that was essentially virgin Teflon colored green. Once I understood what they were recommending I objected. They said they were right and I needed to follow their advise. I said it would wear quickly. They said that was no problem because you could just replace it when it wears. That was the end of the relationship. I connected with another world class seals company. They agreed carbon was the correct filler. But I was not happy because their carbon wasn't as fine and slick as the OEM. I had them assess the OEM and they found it was carbon but couldn't identify a grade. We launched the seals kit with the standard carbon and ran into issues. It would take 500 city miles for the seals to break in before achieving the performance benefits. Some people had codes during this period. I complained to the seals company. Then I connected with a world class seals materials company. They assess the OEM Teflon and told me that it had a very special very expensive high grade carbon filler that had a single source in the world. This filler had the wear longevity of carbon but was almost as low in friction as virgin Teflon. They recommended it for this vanos application. I switched to this material and the issues significantly resolved. The seals were breaking in in 200 miles. Most of the code issues were gone. We would infrequently see a code just after install before the seals broke in. I found out new vanos units can also experience this. I then had the Teflon rings polished when manufactured. This resolved all the issues and even further reduced the break in period. I had to switch to a smaller seals company to use this material. Essentially no large seals company will offer or use this material because it's too expensive and they are all about reducing costs and increasing profits. With the new seals company we had custom molds made for the seals, $3k each. This allowed creating Teflon billets close to the final dimensions of the seals before sintering and then machining. This notably reduced material loss from machining and facilitated using this very high grade very expensive material.
There are also many variations of Viton rubber. One big issue in the vanos application is compression set. This the flattening of the O-ring. This happens over time due to the compression of the O-ring. There are variations of Viton that facilitate better compression set. We were fortunate to connect with a manufacturer who's O-rings do well with compression set. I have seen many results of compression set over the years and this material does well.
If you look at the ebay listing for i6 Automotive for the double seals kits they specify "Bronze impregnated Teflon". As explained this is too harsh and could damage the vanos soft aluminum cylinder wall and would provide poor performance. Bronze also comes in grades. The standard bronze grade, which is likely what's used, is very course and harsh. We (Beisan) use bronze filler on the S54/S62 Teflon seals. This is appropriate for this application because the cylinder walls are hardened steel and the oil pressure is 1,500 PSI. But we use a very high grade fine bronze filler. This is the same as the OEM.
Another ebay offering by i6 Automotive for the double seals kit has light gray Teflon rings. This is indicative of glass-moly filler. This is the cheapest and harshest material available.
Although the Beisan seals kit is expensive, you do get a lot of value with it. It provides very high grade materials that have been proven with years of install and use. You get a very good procedure to guide you through the repair. I am available continuously by phone and email for support. There is a vanos forum on Bimmerboard where I moderate and answer questions. If you damage any of the seals during the install Beisan will send you replacements at no charge. If you have performance issues or the install doesn't resolve your problem I am always ready to help. I have helped thousands of owners with these issue.
On another note, always use OEM valve cover gaskets. I have recently checked them and BMW has switched to Viton. These new gaskets will last a very long time. All the aftermarket valve cover gaskets I'm aware of are Buna and harden and fail.
I will write a separate post about this to let everyone know.
Sillä taitaa tosiaan hieman olla merkitystä mistä tiivisteet ostaa.
Toki Beisan haluaa omiansa mainostaa, mutta kannattaa lukea.
You need to be careful of what seals material you are getting. There are many variations of Teflon and to some extent Viton.
Teflon isn't usually used in it's virgin (white) form because it's susceptible to wear and deformation. So normally fillers are added to improve this. Choosing the correct type and grade of the filler is very important. In this vanos application BMW chose a very high grade carbon as the filler. This is correct for several reasons. The vanos has soft non-anodized aluminum cylinder walls and the engine oil pressure is very low, 7.5-60 PSI, compared to the normal hydraulic applications 1,500 PSI. So you need a material that doesn't eat the cylinder walls as the Teflon slides against it, and that allows low enough friction to provide good performance (speed). Graphite would not damage the cylinder walls and has very low friction, but it is fairly susceptible to wear and wouldn't last long. Bronze and glass-moly are too harsh and would damage the cylinder walls and provide poor performance.
When I (Beisan) first looked into this I connected with the largest seals company in the world. They recommended a turquoise Teflon that was essentially virgin Teflon colored green. Once I understood what they were recommending I objected. They said they were right and I needed to follow their advise. I said it would wear quickly. They said that was no problem because you could just replace it when it wears. That was the end of the relationship. I connected with another world class seals company. They agreed carbon was the correct filler. But I was not happy because their carbon wasn't as fine and slick as the OEM. I had them assess the OEM and they found it was carbon but couldn't identify a grade. We launched the seals kit with the standard carbon and ran into issues. It would take 500 city miles for the seals to break in before achieving the performance benefits. Some people had codes during this period. I complained to the seals company. Then I connected with a world class seals materials company. They assess the OEM Teflon and told me that it had a very special very expensive high grade carbon filler that had a single source in the world. This filler had the wear longevity of carbon but was almost as low in friction as virgin Teflon. They recommended it for this vanos application. I switched to this material and the issues significantly resolved. The seals were breaking in in 200 miles. Most of the code issues were gone. We would infrequently see a code just after install before the seals broke in. I found out new vanos units can also experience this. I then had the Teflon rings polished when manufactured. This resolved all the issues and even further reduced the break in period. I had to switch to a smaller seals company to use this material. Essentially no large seals company will offer or use this material because it's too expensive and they are all about reducing costs and increasing profits. With the new seals company we had custom molds made for the seals, $3k each. This allowed creating Teflon billets close to the final dimensions of the seals before sintering and then machining. This notably reduced material loss from machining and facilitated using this very high grade very expensive material.
There are also many variations of Viton rubber. One big issue in the vanos application is compression set. This the flattening of the O-ring. This happens over time due to the compression of the O-ring. There are variations of Viton that facilitate better compression set. We were fortunate to connect with a manufacturer who's O-rings do well with compression set. I have seen many results of compression set over the years and this material does well.
If you look at the ebay listing for i6 Automotive for the double seals kits they specify "Bronze impregnated Teflon". As explained this is too harsh and could damage the vanos soft aluminum cylinder wall and would provide poor performance. Bronze also comes in grades. The standard bronze grade, which is likely what's used, is very course and harsh. We (Beisan) use bronze filler on the S54/S62 Teflon seals. This is appropriate for this application because the cylinder walls are hardened steel and the oil pressure is 1,500 PSI. But we use a very high grade fine bronze filler. This is the same as the OEM.
Another ebay offering by i6 Automotive for the double seals kit has light gray Teflon rings. This is indicative of glass-moly filler. This is the cheapest and harshest material available.
Although the Beisan seals kit is expensive, you do get a lot of value with it. It provides very high grade materials that have been proven with years of install and use. You get a very good procedure to guide you through the repair. I am available continuously by phone and email for support. There is a vanos forum on Bimmerboard where I moderate and answer questions. If you damage any of the seals during the install Beisan will send you replacements at no charge. If you have performance issues or the install doesn't resolve your problem I am always ready to help. I have helped thousands of owners with these issue.
On another note, always use OEM valve cover gaskets. I have recently checked them and BMW has switched to Viton. These new gaskets will last a very long time. All the aftermarket valve cover gaskets I'm aware of are Buna and harden and fail.
I will write a separate post about this to let everyone know.
Vanhoilla oli menty jo 10tkm ja oli mittatikun alarajassa. Tein samalla huuhtelun. En sitten tiedä lähtikö sieltä joku tukos pois tuolla huuhtelulla vai johtuiko öljyn vähyydestä.
Comment