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whats the spring pressure on that cam? Thats one of the advantages to roller cam bearings, 700+lbs open and the cam will tend to squish all the oil off a regular bearing and possibly stick.
 

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We run those on the circle track motor, extremely cool bearings =). Pro's are pretty clear, less rolling resistance/friction etc. Also as Woody1 mentioned above, they can take much higher spring pressure. The main drawback is the block has to be machined by someone who knows what they're doing specifically for those bearings as they have a larger OD than regular bearings. If it weren't for that, I'd use them on every motor =).

Cris
 

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Also, I just talked to my dad, and he said that at least in his aluminum blocks these bearings wear out. They needles indent into the soft material of the bearing race. He IS however running them in his iron block at the moment and hasn't had a problem. He stressed to me again that the machinist installing them know what they are doing, as the interferance fit of these is QUITE different than a regular cam bearing. If you machine just a hair too much, they will simply fall out of the block.

Hope this helps

Cris
 

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The main drawback is the block has to be machined by someone who knows what they're doing specifically for those bearings as they have a larger OD than regular bearings. If it weren't for that, I'd use them on every motor =).
Why not have the cam machined for a smaller ID bearing instead of machining the block?
 

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Umm...don't think they make a smaller ID bearing in a roller style? I don't know lol. I know that the roller bearings have a standard ID, with a much larger OD. I guess the thinking might be that once you machine the block you can use any cam you want. If they made them with a smaller ID, you'd have to have every cam you put in that block machined down.

Cris
 

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Hmmm i thought i heard also that the cam had to have a harder bearing surface designed to ride on the hard steel rollers?? any thought on that sub??
 

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Dunno, when my dad replaced his original solid roller with the same grind 4-7 swap cam (yeah, SBC bleh) he didn't specify any particular bearing. Maybe because it's a billet roller grind? I couldn't say though about any other application...just what we use them for.
 

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Not being an expert on the subject but when I mentioned needle roller cam bearings to my engine builder his initial response was they are overkill for all but the most specialist applications. His logic was how many times do you see a failed standard cam bearing?

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Martyn
 

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On 2006-09-25 09:15, martynUK wrote:
Not being an expert on the subject but when I mentioned needle roller cam bearings to my engine builder his initial response was they are overkill for all but the most specialist applications. His logic was how many times do you see a failed standard cam bearing?

Regards,
Martyn
when you run high spring pressure you can very likely see a stuck bearing
 

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On 2006-09-25 09:15, martynUK wrote:
Not being an expert on the subject but when I mentioned needle roller cam bearings to my engine builder his initial response was they are overkill for all but the most specialist applications. His logic was how many times do you see a failed standard cam bearing?

Regards,
Martyn
It is overkill, from a durability standpoint. But when you are wanting to extract every ounce of horsepower from a motor, it's not really that big an investment for the return. Every race motor we build for the circle track car will have them. Our machinist has seen the difference on the dyno as well. I'll have to ask him for some specifics if he can give them to me. I mean, imagine turning a standard cam by hand...it turns a few turns, maybe. Trust me though...you can spin my dads cam, and it goes on and on and on... bzzzzzzzzzzzzzzz...lol, extremely cool =).

That has to be worth some horsepower I'd think =).

Cris
 
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