Hi Gents,
Thought of sharing this.
I have a long list of services to perform on Nick's M3, some mini projects are boring but will
share the interesting stuff.
Nick had his bearings replaced pretty recently like ~1000 miles ago. Oil pan gasket
is leaking like a pig to a point he was afraid to drive the car to my shop...but he made it.
The bearing replacements were done with STD-Glyco OE bearings and they were sent out to
WPC treatment.
Attention. To each our own.
WPC has absolutely no benefits whatsoever from any point of view for bearings. I have proved
this times and times again. It's money spent in a very wrong direction. Its surface treatment
that has absolute no benefits in this specific application.
The best choice one can choose for bearings is Molybdenum Disulfide known as Moly or
Irox coating. They are similar.
S54 with its inline-6 platform the crank is subject to constant twists at hi revs. The factory original
clearance of 0.038mm is fine for lower revving engine concept. But not ideal choice for 8000rpm and
up..because when the crankshaft twist it will reduce the oil clearance at the edges. Please note at
~1000miles how the bearings are worn out at the edges where the crank has been twisting.
The best choice for high revving engines and what it has been working for me on S14/S38/S54/S65/S85 etc
hi revving platform is bearings with Moly with increased oil film. This concept is for longevity and keeping the
rods in the block. Not rods shooting holes thru the block.
It is thru that tight tolerances will produce tiny more HP, on NASCAR engines the bearing clearances are very
tight, and they run thin oil. Well after 500-1000 miles with 9000rpm the bearings will require replacement for sure.
(race engine maintenance)
So, I will trade 5hp at 9000rpm for longevity and 5hp less at 9000rpm.
My #1 choice of bearing is ACL HX with increased clearance. From that point on I prep the bearings for Moly coating.
The HX ACL bearings on std not polished S54 crank is 0.051mm. My target with Moly coating not less than 0.051mm,
in this instance I ended up with 0.055mm. Have been doing the moly coating for a long time and I have mastered this
process.
I have tried every possible concept of lubricant to dress parts during engine build in various areas. In this area
I use Driven hi preassure assembly line grease for the bearings. Before one comments about the feel on turning
the parts one can assemble with let say 0W20 and check how the parts will turn and then disassemble and use
the Driven high pressure grease. In this case were we know the engine is running perfect no need to perform a test.
So directly Driven is used. The oil pump is also apart for inspection, after start the initial oil pressure build up will be
longer than normal.
During rod bearing replacement the spark plugs are out so that the grease will not be completely squeezed
due to building unwanted combustion pressure during turning the crank.
Moving forward.
Regards,
Anri
1000miles
1000 miles
Thought of sharing this.
I have a long list of services to perform on Nick's M3, some mini projects are boring but will
share the interesting stuff.
Nick had his bearings replaced pretty recently like ~1000 miles ago. Oil pan gasket
is leaking like a pig to a point he was afraid to drive the car to my shop...but he made it.
The bearing replacements were done with STD-Glyco OE bearings and they were sent out to
WPC treatment.
Attention. To each our own.
WPC has absolutely no benefits whatsoever from any point of view for bearings. I have proved
this times and times again. It's money spent in a very wrong direction. Its surface treatment
that has absolute no benefits in this specific application.
The best choice one can choose for bearings is Molybdenum Disulfide known as Moly or
Irox coating. They are similar.
S54 with its inline-6 platform the crank is subject to constant twists at hi revs. The factory original
clearance of 0.038mm is fine for lower revving engine concept. But not ideal choice for 8000rpm and
up..because when the crankshaft twist it will reduce the oil clearance at the edges. Please note at
~1000miles how the bearings are worn out at the edges where the crank has been twisting.
The best choice for high revving engines and what it has been working for me on S14/S38/S54/S65/S85 etc
hi revving platform is bearings with Moly with increased oil film. This concept is for longevity and keeping the
rods in the block. Not rods shooting holes thru the block.
It is thru that tight tolerances will produce tiny more HP, on NASCAR engines the bearing clearances are very
tight, and they run thin oil. Well after 500-1000 miles with 9000rpm the bearings will require replacement for sure.
(race engine maintenance)
So, I will trade 5hp at 9000rpm for longevity and 5hp less at 9000rpm.
My #1 choice of bearing is ACL HX with increased clearance. From that point on I prep the bearings for Moly coating.
The HX ACL bearings on std not polished S54 crank is 0.051mm. My target with Moly coating not less than 0.051mm,
in this instance I ended up with 0.055mm. Have been doing the moly coating for a long time and I have mastered this
process.
I have tried every possible concept of lubricant to dress parts during engine build in various areas. In this area
I use Driven hi preassure assembly line grease for the bearings. Before one comments about the feel on turning
the parts one can assemble with let say 0W20 and check how the parts will turn and then disassemble and use
the Driven high pressure grease. In this case were we know the engine is running perfect no need to perform a test.
So directly Driven is used. The oil pump is also apart for inspection, after start the initial oil pressure build up will be
longer than normal.
During rod bearing replacement the spark plugs are out so that the grease will not be completely squeezed
due to building unwanted combustion pressure during turning the crank.
Moving forward.
Regards,
Anri
1000miles
1000 miles