Roller Cam Bearings?
01-08-2016 | 07:37 AM
#54
Banned
Joined: Oct 2015
Posts: 277
Likes: 1
Absolutely no experience here, just round table thinking out loud talk.
The lifters and cam lobes are getting oiled right ? Of course...so, this could be plenty of oil getting to the cam bearing.
Back to 2 strokes and roller bearing connecting rod and cranks, remember, they are using 60:1 - 70:1 fuel
il ratios now. This means the roller bearings are seeing 60 to 70 parts fuel to 1 part oil, and surviving. Also remember, this is all in crankcase 'windage mist' - no splash and no direct oiling. Fuel is a cleaner, not to mention the stergents in pump fuel and the dtergents in the oil itself. Yes, some of us older blowhards are modifying our oil systems to get back to old school 50:1 ratios with our 2 strokes, but this is more for piston protection. These are spinning 8000-10,000 crank rpm vs camshafts which in a 4 stroke the cam spins 1/2 crank speed.
The only roller crank bearing failures in 2 trokes are usually because they are not large enough for the forces they see. In these applications, when larger bearings are used, problems go away. Anyone tell that I'm a Polaris guy ? Hah !
Ending my out loud thinking, I would call Dart. Your worry may become a non worry....Hopefully. LOL.
The lifters and cam lobes are getting oiled right ? Of course...so, this could be plenty of oil getting to the cam bearing.
Back to 2 strokes and roller bearing connecting rod and cranks, remember, they are using 60:1 - 70:1 fuel
il ratios now. This means the roller bearings are seeing 60 to 70 parts fuel to 1 part oil, and surviving. Also remember, this is all in crankcase 'windage mist' - no splash and no direct oiling. Fuel is a cleaner, not to mention the stergents in pump fuel and the dtergents in the oil itself. Yes, some of us older blowhards are modifying our oil systems to get back to old school 50:1 ratios with our 2 strokes, but this is more for piston protection. These are spinning 8000-10,000 crank rpm vs camshafts which in a 4 stroke the cam spins 1/2 crank speed.The only roller crank bearing failures in 2 trokes are usually because they are not large enough for the forces they see. In these applications, when larger bearings are used, problems go away. Anyone tell that I'm a Polaris guy ? Hah !
Ending my out loud thinking, I would call Dart. Your worry may become a non worry....Hopefully. LOL.
01-09-2016 | 07:35 AM
#58
Registered
Joined: Jan 2006
Posts: 3,598
Likes: 1,168
From: taxachusetts
