Roller cam bearings

[Mark Ugrich]

Are there any real advantages to using a roller vs. a Babbitt bearing? I’ve never had any personal experience using them.

[FED 387]

depends on the application--

[voltdr]

A very good friend of mine that knows a few things about engine building and find HP told me that when the engine is running, the camshaft is spinning on a film of oil. It isn't dragging against the bearing material.
Dan

[Mark Ugrich]

Thanks to everyone for your comments and insights. I think I’ll stick with Babbitt bearings.

[nhramnl]

Originally Posted by Mark Ugrich

Are there any real advantages to using a roller vs. a Babbitt bearing? I’ve never had any personal experience using them.

Really interesting question. A person's intuitive reaction would be "of course, look at things like roller lifters and rockers", but I'll bet there aren't many engine builders who have actually done an A-B-A comparison of cam bearings.

[SSDiv6]

Babbitt is the only way to go.

Roller bearings, when turning the camshaft on the engine stand, the camshaft feels drag free and it turns easily. However, during engine operation and load, there is more drag while turning. When using high spring pressures, the loading may cause the needle bearings to fail.

[Todd Gross]

The biggest advantage of roller bearings are that they do not need pressurized oiling. So in most V8's you are blocking off 5 oil leaks inside an engine.

[HP HUNTER]

Originally Posted by Todd Gross

The biggest advantage of roller bearings are that they do not need pressurized oiling. So in most V8's you are blocking off 5 oil leaks inside an engine.

YES

[Mark Ugrich]

Originally Posted by Todd Gross

The biggest advantage of roller bearings are that they do not need pressurized oiling. So in most V8's you are blocking off 5 oil leaks inside an engine.

So the advantage would relate to less oil coming from the cam journals, reducing windage in the crankcase?

[SSDiv6]

Originally Posted by Todd Gross

The biggest advantage of roller bearings are that they do not need pressurized oiling. So in most V8's you are blocking off 5 oil leaks inside an engine.

The roller bearings still need some pressurized oiling; they do not oil by themselves and although there are claims oil splash is enough, I have seen enough damaged roller bearings due to lack of oiling especially on endurance engines.
If you have the right cam journal an lifter bore clearance, you will not have to worry.
Yes, they are known to create harmonics issues and it shows in Spintron testing.