mixing Coated and NON Coated Bearings

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
Kenny M
Member
Member
Posts: 82
Joined: Sun Mar 24, 2013 12:31 pm
Location:

mixing Coated and NON Coated Bearings

Post by Kenny M »

Has anyone used Half Coated and Half Non Coated bearings to set clearance??
englertracing
Guru
Guru
Posts: 1547
Joined: Thu Sep 29, 2011 8:55 am
Location:

Re: mixing Coated and NON Coated Bearings

Post by englertracing »

I havent but i cant imagine why it would be an issue.
jed
HotPass
HotPass
Posts: 875
Joined: Tue Nov 18, 2008 4:18 pm
Location: Dallas

Re: mixing Coated and NON Coated Bearings

Post by jed »

I have done it several times in rod and main bearings with no problems.
BlitzA64
Expert
Expert
Posts: 731
Joined: Sun Feb 28, 2010 8:49 pm
Location:

Re: mixing Coated and NON Coated Bearings

Post by BlitzA64 »

Yep
Kenny M
Member
Member
Posts: 82
Joined: Sun Mar 24, 2013 12:31 pm
Location:

Re: mixing Coated and NON Coated Bearings

Post by Kenny M »

Thanks for the reply's. The Clevites are .005 thicker than the non coated and ACLs are a full.001 thicker than the Clevite.
BlitzA64
Expert
Expert
Posts: 731
Joined: Sun Feb 28, 2010 8:49 pm
Location:

Re: mixing Coated and NON Coated Bearings

Post by BlitzA64 »

The engine I built a few months ago has both. I had 3 sets of mains and rods to mix and match. I was being overly anal on with it but a lot of time and money invested and I wanted what I wanted
User avatar
Dave Koehler
Vendor
Posts: 7197
Joined: Mon Oct 04, 2004 11:19 pm
Location: Urbana, IL USA
Contact:

Re: mixing Coated and NON Coated Bearings

Post by Dave Koehler »

Kenny M wrote: Sat Jan 11, 2020 12:31 pm Thanks for the reply's. The Clevites are .005 thicker than the non coated and ACLs are a full.001 thicker than the Clevite.
I believe you might be missing a 0 in your dimensions.
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
engineguyBill
Guru
Guru
Posts: 1264
Joined: Fri Feb 26, 2010 11:15 am
Location: Gold Canyon, AZ

Re: mixing Coated and NON Coated Bearings

Post by engineguyBill »

Coating on a typical Clevite plated bearing is .00035" per shell, therefore the total difference on vertical oil clearance on the coated shells is .0007" per journal. Therefore the coated shell may be used with an uncoated shell to juggle the oil clearance just the same as utilizing a shell from a .001" journal set. i.e. .00035" versus .0005 clearance difference.
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
bentvalves
Expert
Expert
Posts: 537
Joined: Mon Dec 12, 2016 3:37 pm
Location:

Re: mixing Coated and NON Coated Bearings

Post by bentvalves »

I would put the coated shell on the bottom of the mains and top of the rods and at least put that coating to work.
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: mixing Coated and NON Coated Bearings

Post by MadBill »

The write up I read (I forget which bearing company) said the coating thickness should be ignored in measuring the clearance. In other words, if they coat a standard size pair of shells it's still considered a standard size set.:-k
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
engineguyBill
Guru
Guru
Posts: 1264
Joined: Fri Feb 26, 2010 11:15 am
Location: Gold Canyon, AZ

Re: mixing Coated and NON Coated Bearings

Post by engineguyBill »

MadBill wrote: Sun Jan 12, 2020 9:56 pm The write up I read (I forget which bearing company) said the coating thickness should be ignored in measuring the clearance. In other words, if they coat a standard size pair of shells it's still considered a standard size set.:-k
No, you need to take the coating thickness into account when checking bearing oil clearances. For instance a Clevite STD COATED bearing will have approximately .0007" LESS oil clearance than the same bearing STD size. "Ignoring" the coating thickness will result in problems when calculating oil clearances.
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
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: mixing Coated and NON Coated Bearings

Post by MadBill »

I think my info was from Calico; I'll have to check my records. Here's their FAQ reference:

https://www.calicocoatings.com/company/coating-faqs/

"Will I have to change my clearances to use coatings?
Calico's CT-1 dry film lubricant used on engine bearings, valve springs, oil pump gears, timing and transmission gears is 0.0002" to 0.0004" thick and generally does not require extra clearances. A benefit of Calico coated bearings is the allowance for tighter clearances. Keeping in mind that bearing clearances of .002" to .003" are typical for high performance applications."
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
User avatar
modok
Guru
Guru
Posts: 3321
Joined: Sun Jun 06, 2010 1:50 am
Location:

Re: mixing Coated and NON Coated Bearings

Post by modok »

engineguyBill wrote: Sat Jan 11, 2020 5:04 pm Coating on a typical Clevite plated bearing is .00035" per shell, therefore the total difference on vertical oil clearance on the coated shells is .0007" per journal. Therefore the coated shell may be used with an uncoated shell to juggle the oil clearance just the same as utilizing a shell from a .001" journal set. i.e. .00035" versus .0005 clearance difference.
Agree 100%
Clevite will not steer you wrong if you follow recommendations in the catalog.

Or, as a general guess I'd say far as target clearance, you -can- run .0005" less clearance with coated bearings, or in this case .00025 less with one coated shell.

IMO you can mix different brands of bearing shell, even different materials, and never have I heard a single problem from it.
Tho for whatever reason people rarely do that, so.... can't say we know for sure in every scenario.
Even some OE engines use tri-metal bearing for the top shell of the conrod, with an aluminum bottom shell. Seems pretty clever. I setup a few other oddball engines I rebuilt that same way and they all did fine.

IMO go for it.
Post Reply