Main and Big-End bearing selection

[Careless]

hey Fellaz.

 

Maybe someone with RB specific experience will chime in here, or someone might post some RB30 specific info, even better!

 

I'm looking for some bearing selection help. I'm going with CalicoCoatings CT-1 on a set of ACL RACE Series Bearings.

 

Here's the spec sheet (see attached)

 

Problem here is the "X" series bearing. It has an additional .001 of oil clearance. Is this to allow more oil to seep between the bearings, or is this to aid in making up clearance issues where they fall short?

 

I don't have the pages from the FSM for the bearing clearances or the crank snout stampings, and Gregories hasn't shipped my book over, as far as I know (not sure whats going on with them, it's been 3 weeks). Heck I don't even know if that's in the book. So who knows?

 

I suppose that since it's additional clearance, it would be used to increase the ability of the crank to spin up freely with more oil, rather than tighten it up more. I'm just wondering if it's at all worth it, and whether it's a preference related option, rather than a tolerance related one (seeing as the bearings come oversized as well, but that's for cranks that need machining or fall short, right?)

 

Might use plastiguage to do my bearing readings, unless I can find a nice set of Mics. (any leads?). I figure that since the dude doing the machining does his using plastigauge, I might as well go at it myself when I get my ARP Mains (apparently you're supposed to check clearances with the hardware you're gonna use, even if it's just a fastener, which is understandable)

 

Thanks gents.

[triple B]

well increasing the oil clearance increase the amount of oil going over the bearing. remember besides lubricating the bearing surface it also cools the bearings.

 

when you increase the oil clearance this can cause a drop in oil pressure espcially if its big. this is why people upgrade to n1 oil pumps and bigger.

 

i am not sure if .001 is going to cause a huge fluctuation in pressure but it will help prolong the bearing life.

 

also plastaguage is the best thing ( in my expereince) to measure bearing clerances. just make sure everything it torqued down to spec when measuring though

[Careless]

Ok, so I ordered the Calico Coatings CT-1 sprayed on the .0001 extra oil clearance ACL bearings.

 

Total price = 250 dollars for Rod and Main bearings. I found regular ACL bearings on ebay for roughly 150 for the set, but I'm going to go with the coated bearings this time around. Shipping using the "Saturday Delivery" from UPS was free. So considering that I would have paid anywhere from 50+ for shipping from UPS on ebay, I think 250 ain't so bad. It's either 200 without or 250 with coatings.

 

=)

 

now if my Gregory's manual would come... *shakes fist*

 

EDIT: ANNNND i bought their 8 dollar Calico Coatings All American Challenge Sports Cap, too. heheheh =)

 

Hey for 8 bucks, I think it's time to replace my current cap. it's way past its time. Maybe I should order CT-1 coating on the hat too, so it lasts longer and is less prone to "wear"...