Main/Rod Bearing Clearances

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03-12-2019 | 09:39 AM

automobili_v12

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From: Miami, FL

Main/Rod Bearing Clearances

Hi, Im building a 454 Stroker, what Main & Rod Bearing Clearances would be recommended.

03-12-2019 | 11:15 AM

beaver 3

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From: Lagrange ky

I built mine to .0025 - .003. I run 20/50 oil oil pressure is always good. Only about a season and a half on the motor now though probably around 20 hours.

03-12-2019 | 12:22 PM

getrdunn

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From: NW Michigan

Going off memory and not manual but .0027-.003 on rods and .003-0035 on mains. Some shops run slightly more clearance or the rear main. Closed or open cooling? I've always went by marine engine speed shop and seems like we always ran on the higher side due to the cooler water and oil temps. BUP should be able to get you spot on if he chimes in.

03-17-2019 | 11:06 AM

flashgordon

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From: new baltimore mi

i have 0028 on rods and 0035 on the mains

04-18-2019 | 07:40 PM

automobili_v12

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From: Miami, FL

Can anyone else chime in,

Thx

04-18-2019 | 09:13 PM

sutphen 30

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From: taxachusetts

Quote:

Originally Posted by automobili_v12

Can anyone else chime in,

Thx

why,,how tight are yours?

04-18-2019 | 09:31 PM

Rookie

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From: Grand Rapids, MI

Quote:

Originally Posted by automobili_v12

Can anyone else chime in,

Thx

Those are the proper tolerances. What more are you looking for? I run on the higher end. Cooler engines (120°F) and oil 165°F, 15/50 Mobil 1 oil.

04-19-2019 | 09:21 AM

automobili_v12

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Should I run the bearings -.001 extra on the clearances for more Lubrication?

04-19-2019 | 10:34 AM

ph1971

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From: North Florida

.0028 main and .0025 rods in my 540

04-19-2019 | 10:20 PM

#10

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From: Grand Rapids, MI

Quote:

Originally Posted by automobili_v12

Should I run the bearings -.001 extra on the clearances for more Lubrication?

No, you should run within the tolerances given. Lubrication is a little portion of oil. More importantly it works as a hydraulic stabilizer when the charge is set off in the combustion chamber. The oil is a non-compressible fluid and creates a cushion between the journals and crank so they don't slam into one another. Tolerances are critical and no need for you to try to engineer new tolerances. Between the given tolerances is personal preference and build design specific.