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 This tech tip/FAQ reveals the correct torque specifications and steps to properly install the Brian Crower H-beam connecting rods with the ARP 2000 12 pint fasteners in the Chrysler 2.2 and 2.5 engine. For proper rod bolt installation on Brian Crower connecting rods, please follow these important steps.
- Rod bolt threads and underside of bolt head should be lubricated thoroughly with supplied BC/ARP lube.
- Cap should be seated on rod by aligning cap by hand and tapping in place using a rubber mallet.
- Alternate tightening of bolt to avoid cocking the cap.
- Torque the fastener to achieve bolt stretch using the torque range below.
- Use a quality rod bolt stretch gauge, as improper bolt stretch will cause premature failure.
- If using a torque wrench sequence, torque initially to 10 ft lbs, then use one consistent pull to achieve the proper torque specification listed below.
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BOLT DIAMETER
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MATERIAL
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U.H.I
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BOLT STRETCH
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TORQUE SPEC.
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5/16”
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ARP 2000 - 220,000 psi
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1.500”
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.0050” to .0055”
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25-28 ft/lbs
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3/8”
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ARP 2000 - 220,000 psi
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1.600”
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.0055” to .0060”
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45-50 ft/lbs
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3/8”
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ARP625+ 280,000 psi
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1.600”
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.0063” to .0067”
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50-55 ft/lbs
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7/16”
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ARP 2000 - 220,000 psi
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1.600”
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.0055” to .0060”
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65-70 ft/lbs
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7/16”
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ARP 2000 - 220,000 psi
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1.800”
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.0060” to .0065”
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70-75 ft/lbs
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Torque used during manufacturing: 26 ft lbs – 5/16”, 45 ft lbs – 3/8” and 70 ft lbs – 7/16”
To accurately determine the life of a fastener, it is recommended to log the fastener’s original un-torqued free length and compare to free length after tear downs. If the free length increases by more than .001”, or there is any deformation or galling, the bolts must be replaced or failure could result.
Fasteners are susceptible to corrosion so caution must be used when handling with bare hands or left out in the open to prevent exposure.
Clearances below are a general guideline and may vary according to the application and engine builder preferences.
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ROD BEARINGS
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.002 to .003
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SIDE CLEARANCE
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.015” to .025”
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PISTON PIN
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.0008” to .0015”
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ROD TO BLOCK OR CAM
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Minimum .060”
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