Offshoreonly.com - Roller Cam Bearings?

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Quote:

Originally Posted by horsepower1 (Post 4387122)

If you're starting with a round lobe core then the lobe size isn't really an issue. The only real benefit is stability and I don't think you can get too much of that in these off shore deals, especially in something high end like you're building. If the bore is already there and the 60 is in your budget, then I'd say go for it and use a babbitt bearing. What size lifter are you running? Might as well go .937 at that point.

.937 Jesels
What would be the benefit from the larger core and what if any would be the pitfalls?

who's block did you get??

Quote:

Originally Posted by Black Baja (Post 4387185)

Dart

time for A 5" crank!!

Quote:

Originally Posted by adk61 (Post 4387188)

time for A 5" crank!!

And #6 Drive

Quote:

Originally Posted by adk61 (Post 4387188)

time for A 5" crank!!

I almost went 5-1/2" but when is enough enough?

Quote:

Originally Posted by 14 apache (Post 4387193)

And #6 Drive

#5 unless I hit the lottery again

Quote:

Originally Posted by Black Baja (Post 4387158)

.937 Jesels
What would be the benefit from the larger core and what if any would be the pitfalls?

Larger base circle and lobe circumference. More rigid and the lobes can be ground much more precisely. Combined with the larger wheel on the lifter it reduces pressure angle and lifter side loading. No pitfalls.

Quote:

Originally Posted by horsepower1 (Post 4387284)

Here is what bothers me at this point. Increased bearing journal diameter at some point has to become an issue. Why? More surface area... More surface area = more heat. At this point the Pro-Stockers are going to a 68mm cam but they are using Clam Shell bearings. Why? Well that's above my pay grade but based on my experience I would have to say for two reasons. The first one is obvious. But I believe the second one is to free-up some of the bearing surface area. Largest motor I ever worked on had a 96mm cam yes 96 not 69. It had roller bearings in it. When you hold a cam of that size in your hands and you think 9,500 rpm how much heat is this baby going to generate?
The other thing that's going to happen with this build is the lifter is going to be moved up higher and the oil galley for the lifters will have to be addressed with possibly bushing or cutting a groove in the lifter.
So instead of buying an $800 cam and scrapping what I have it's going to turn into $2000 before all is said and done. And again I ask myself when is enough enough?

The larger the bearing, the bearing speed slows down yes....? I always was under the impression that was true. Slower bearing speed, less heat, then higher rpm durability.

More load carrying area too...?