Cylinder Honing
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G
Guest
·unless the cylinder is scored i wouldn't bother... if the cross-hatch and plating are in place it should be fine. like a said earlier... if you're going to replate 'em you should seriously consider boring them out and replating them for a 944 kit
NICASIL??? Our cylinder walls are NICASIL?
Same nicasil BMW used on E38 7-series V8 engines? The one that deteriorated due to exposure to sulfur in US gasoline and made BMW recall all the cars for leakdown tests and replace engines with the new Alusil ones?
Say it ain't so
Same nicasil BMW used on E38 7-series V8 engines? The one that deteriorated due to exposure to sulfur in US gasoline and made BMW recall all the cars for leakdown tests and replace engines with the new Alusil ones?
Say it ain't so
I've been told that most, if not all, modern motorcycle cylinders are nikasil plated (not to mention most aluminum block car engines). Nobody sleeves aluminum cylinders anymore (I think the CR500 is still sleeved, but that's a 10+ year old design.)
I did have the plating fail on one of my KTMs (It was about 3 years old at the time). The plating kinda 'blistered' and took out the entire top end of the bike. I was told that the factories use a minimal thickness of nikasil, like .002 - 003". When professional engine shops bore and re-coat a cylinder they'll typically open the cylinder up enough to have a plating thickness of at least twice that.
When my cylinder got jacked, I looked into other plating methods like alusil, kanisil, and even ceramic and the input that I got from most of the people in the motorcycle engine building business was that although nikasil occasionally had it's problems, the other plating methods had their own weaknesses that made them even less desirable for use in cylinder plating.
BTW, Nikasil (notice the capital 'N') is a proprietary process of Mahle industries, but nickle - silicon carbide coatings, typically referred to as nikasil, is available from several sources in the US.
--Fillmore
I did have the plating fail on one of my KTMs (It was about 3 years old at the time). The plating kinda 'blistered' and took out the entire top end of the bike. I was told that the factories use a minimal thickness of nikasil, like .002 - 003". When professional engine shops bore and re-coat a cylinder they'll typically open the cylinder up enough to have a plating thickness of at least twice that.
When my cylinder got jacked, I looked into other plating methods like alusil, kanisil, and even ceramic and the input that I got from most of the people in the motorcycle engine building business was that although nikasil occasionally had it's problems, the other plating methods had their own weaknesses that made them even less desirable for use in cylinder plating.
BTW, Nikasil (notice the capital 'N') is a proprietary process of Mahle industries, but nickle - silicon carbide coatings, typically referred to as nikasil, is available from several sources in the US.
--Fillmore
G
Guest
·You know too much.
The issue with 7-series (and 5 series with 4.4L engines) was with gasoline engines. BMW has not had a single failure with Nikasil blocks in Europe and massive rate of failure in the US. This resulted in them switching to Alusil and offering to replace the blocks with a new one upon leakdown test failure.
BMW blamed high levels of sulphur in US gasolines for cylinder wall deterioration. If you do a search in Google on Nikasil and BMW you'll find tons of info on this
G
Guest
·I've alwys wanted a ceramic coated engine.
G
Guest
·that's easy just go buy an r1...
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