Brain fade - half shelling a .010 bearing for more clearance
Moderator: Team
-
- Guru
- Posts: 1564
- Joined: Thu Sep 16, 2010 10:01 am
- Location: Virginia
- Contact:
Re: Brain fade - half shelling a .010 bearing for more clearance
There are some automotive applications where oversize o.d. bearings are available. I've line bored a couple of BBC's for .010" over mains. The strangest o.s. I've seen is a .015" over for the Kent Ford 1.6 that's used in many things, Formula Ford being one of them. King now makes a .002" and a .005" for Subaru's.
"do it right or do it right away"
http://www.motionmachineinc.com/
https://www.youtube.com/watch?v=ZgIZbveknDs
http://www.motionmachineinc.com/
https://www.youtube.com/watch?v=ZgIZbveknDs
Re: Brain fade - half shelling a .010 bearing for more clearance
Who's on first.
Honored to be a member of the Luxemburg Speedway Hall of Fame Class of 2019
-
- Guru
- Posts: 1980
- Joined: Sat Mar 08, 2008 3:08 pm
- Location: Minneapolis
Re: Brain fade - half shelling a .010 bearing for more clearance
Actually posts like this get you thinking which is good...
Honored to be a member of the Luxemburg Speedway Hall of Fame Class of 2019
-
- Guru
- Posts: 1264
- Joined: Fri Feb 26, 2010 11:15 am
- Location: Gold Canyon, AZ
Re: Brain fade - half shelling a .010 bearing for more clearance
Think of it this way - when a crankshaft journal is ground undersize, a corresponding "undersize" bearing is needed. Therefore a journal that is ground .010" undersize will need -10 (-.010') bearing set which has thicker shells than a STD bearing set does. SO -.009" bearing has thinner shells than a -.010" and -.011 bearing has thicker shells that the -.010". Therefore, a -.009 bearing will result in additional clearance over the -.010" bearing and the -.011" bearing will have less clearance than the -.010" bearing.
When mix/matching bearing shell sizes, the bearing manufacturers recommend that the thicker shell be placed in the cap side of the main bearing and in the rod body of connecting rods. However, I have done it both ways and have not seen any difference/problems.
When mix/matching bearing shell sizes, the bearing manufacturers recommend that the thicker shell be placed in the cap side of the main bearing and in the rod body of connecting rods. However, I have done it both ways and have not seen any difference/problems.
Last edited by engineguyBill on Fri Jun 08, 2018 1:26 pm, edited 1 time in total.
Bill
Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
Re: Brain fade - half shelling a .010 bearing for more clearance
Lol, if I read you right Bill, you contradicted yourself.engineguyBill wrote: ↑Fri Jun 08, 2018 1:25 pm Think of it this way - when a crankshaft journal is ground undersize, a corresponding "undersize" bearing is needed. Therefore a journal that is ground .010" undersize will need -10 (-.010') bearing set which has thicker shells than a STD bearing set does. SO -.009" bearing has thinner shells than a -.010" and -.011 bearing has thicker shells that the -.010". Therefore, a -.009 bearing will result in additional clearance over the -.010" bearing and the -.011" bearing will have less clearance than the -.010" bearing.
When mix/matching bearing shell sizes, the bearing manufacturers recommend that the thicker shell be placed in the cap side of the main bearing and in the rod body of connecting rods. However, I have done it both ways and have not seen any difference/problems.
Time to get the ball mic out.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
-
- Guru
- Posts: 1980
- Joined: Sat Mar 08, 2008 3:08 pm
- Location: Minneapolis
Re: Brain fade - half shelling a .010 bearing for more clearance
haha.. reread it again.. he has it right. And even I understood it.. which means he succeeded in dumbing it down enough to get the point across to most knuckle headed nut jockeys. errr.. wait.. that didn't sound right.In-Tech wrote: ↑Fri Jun 08, 2018 1:32 pmLol, if I read you right Bill, you contradicted yourself.engineguyBill wrote: ↑Fri Jun 08, 2018 1:25 pm Think of it this way - when a crankshaft journal is ground undersize, a corresponding "undersize" bearing is needed. Therefore a journal that is ground .010" undersize will need -10 (-.010') bearing set which has thicker shells than a STD bearing set does. SO -.009" bearing has thinner shells than a -.010" and -.011 bearing has thicker shells that the -.010". Therefore, a -.009 bearing will result in additional clearance over the -.010" bearing and the -.011" bearing will have less clearance than the -.010" bearing.
When mix/matching bearing shell sizes, the bearing manufacturers recommend that the thicker shell be placed in the cap side of the main bearing and in the rod body of connecting rods. However, I have done it both ways and have not seen any difference/problems.
Time to get the ball mic out.
Like I said in the above when I replied too quickly.. I just went through this with my too loosely clearanced SBF mains. I bought the crank off ebay after it was freshened so ended up doing things ass backwards from a building/clearancing standpoint. Bought coated -.011" mains and all was good again.
Re: Brain fade - half shelling a .010 bearing for more clearance
Hahahaha, I did have to reread it.SO -.009" bearing has thinner shells than a -.010" and -.011 bearing has thicker shells that the -.010". Therefore, a -.009 bearing will result in additional clearance over the -.010" bearing and the -.011" bearing will have less clearance than the -.010" bearing.
Std journal bearing is 2.100" O.D crank (forget built in clearance for this convo)
-.009 journal bearing is for 2.091" O.D. crank, thicker by .009" per pair of shells vs Std. More clearance
-.010 journal bearing is for 2.090" O.D. crank, thicker by .010" per pair of shells vs Std
-.011 journal bearing is for 2.089" O.D. crank, thicker by .011" per pair of shells vs Std. Less clearance
Krooser was right, this was a good memory lesson.
Sorry Bill, I know you know your stuff.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl